## ABSTRACT

application of basic embedding algorithm with preserving the signal norm and minimizing distortions;

concentration of vector coordinates in narrow frequency band and application of OFDM-like multichannel embedding algorithm;

selection a suitable audio frame for embedding in asynchronous watermarking regime and

using error correcting BCH codes.

https://www.w3.org/1998/Math/MathML"> ρ e n c = h Δ σ long   σ frame   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ,

where https://www.w3.org/1998/Math/MathML"> h = 0.5 … 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - a certain threshold factor that specifies data payload; Δ - quantization step; https://www.w3.org/1998/Math/MathML"> σ long   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - long term root mean square (rms) of the host signal in the interval of https://www.w3.org/1998/Math/MathML"> ( 3 - 5 ) s e c ; σ frame   - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> short term rms of the current frame. The floating threshold implements asynchronous mode of watermarked frame transfer and provides approximately constant data payload subject to peak-factor of watermarking signal. 6. 2.5 Error-correction encoding To enhance interference immunity the BoseChaudhuri-Hocquenghem error-correcting code https://www.w3.org/1998/Math/MathML"> B C H ( 63,30,6 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was used. It includes https://www.w3.org/1998/Math/MathML"> k = 30 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> information bits for total block length of https://www.w3.org/1998/Math/MathML"> n = 63 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bits and is capable to correct up to https://www.w3.org/1998/Math/MathML"> t = 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> errors per block [9]. In the maritime mobile service with digital selective calling (DSC) the identification is produced by using of 9-digit number called as maritime mobile service identity (MMSI). According recommendation [10] MMSI is encoded into 30 bit sequence. In this regard https://www.w3.org/1998/Math/MathML"> B C H ( 63,30,6 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> code is just suitable for presenting the entire MMSI by a single watermark. BCH code doesn't belong to class of perfection codes for which every arbitrary sequence from n bit is necessarily decoded to a certain information block. Having decoding inability BCH decoder sets a rejection decoding flag. The probability of decoding failure (or not correcting) one can obtain from the formula: https://www.w3.org/1998/Math/MathML"> P ac = 2 n - 2 k 1 + ∑ i = 1 t   C n i 2 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where https://www.w3.org/1998/Math/MathML"> C n i = n ! i ! ( n - i ) ! - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> binomial coefficients. For https://www.w3.org/1998/Math/MathML"> B C H ( 63,30,6 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> code https://www.w3.org/1998/Math/MathML"> P nc = 0.9912 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Utilization the state of decoding flag provides decreasing of false-negative probability in the detecting algorithm. 7. WATERMARK DETECTION AND Watermark detection is produced by sliding analysis of the received frame of length N samples in the frequency FFT domain. It is essential that detection and decoding processes do not require any starting synchronization and marking. Detection algorithm may be summarized as follows. On every frame AW decoder tries detecting and decoding watermark. The same lattices https://www.w3.org/1998/Math/MathML"> Λ 0 , Λ 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and random sequence u as in AW encoder are used. The basic formulas for single frame processing are presented in the Table 2. Table 2. Detection and decoding In every frequency sub channel correlation coefficient https://www.w3.org/1998/Math/MathML"> y ˘ i https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is computed. Then distances from number https://www.w3.org/1998/Math/MathML"> y ‾ i https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to the nearest lattice node in every sub channel and the total distance D along all channel are calculated. AW decoder approves decision on watermark detection by comparing D to a certain threshold https://www.w3.org/1998/Math/MathML"> ρ det   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> as shown on step 3 in the Table 2 . The value https://www.w3.org/1998/Math/MathML"> ρ det   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> must be set assuming the following conditions. Distance D presents a random value. Its distribution may be approximated by gamma distribution. In the case of watermark gabsence within analyzed frame D is expressed by a sum of n independent uniformly distributed values in the interval https://www.w3.org/1998/Math/MathML"> [ 0 , Δ / 4 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with equal means and root mean square. Mean and rms of D are evidently written taking into account https://www.w3.org/1998/Math/MathML"> m D = m d n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> σ D = σ d n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by the next relations: https://www.w3.org/1998/Math/MathML"> m D = Δn 8 , σ D = Δ 3 n 24 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> In the watermark presence deflections https://www.w3.org/1998/Math/MathML"> d i https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are caused by external interferences. In the absence of any interferences absolute values of correlation coefficients are placed exactly in the lattice nodes https://www.w3.org/1998/Math/MathML"> y ‾ i ∈ Λ 10 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Distributions of D for cases watermark present/absent are shown in Fig. 3 . In watermark application for automatic identification it is necessary to minimize falsenegative probability (shown black). Herewith falsepositive errors (shading) are not critical because the same watermark is permanently transmitted in the form of MMSI. We set decision boundary to https://www.w3.org/1998/Math/MathML"> ρ det   = m D - 5 σ D https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . On account of central limit theorem distribution of D in the watermark presence is satisfactory approximated by normal law https://www.w3.org/1998/Math/MathML"> D ∼ N m D , σ D https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Therefore falsenegative probability may be estimated through error function that gives https://www.w3.org/1998/Math/MathML"> P PN ≈ 2 × 10 - 7 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for parameters https://www.w3.org/1998/Math/MathML"> Δ = 1 , n = 63 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Figure 3 . Distributions of D BCH decoder decreases the total false-negative probability on account of rejection of decoding with the previously computed probability https://www.w3.org/1998/Math/MathML"> P nc = 0.9912 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Hence the resulting false-negative probability assuming formula (3) comes to the value https://www.w3.org/1998/Math/MathML"> P false   = P FN 1 - P nc ≈ 2 × 10 - 9 .   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 8. RESULTS OF SIMULATION AND EXPERIMENT Proposed AW algorithms was thoroughly investigated in conditions of varying independent parameters and influence the whole spectrum of interferences which can take place in the real channel. Computer simulation was carried out in MatLab environment for speech wav-files with sampling frequency https://www.w3.org/1998/Math/MathML"> F s = 8 k H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Simulation results that refer to data payload and fidelity subjected to step size Δ and threshold factor h from formula (2) are shown in the Table 3. Data payload is considered as the total number of pure bits related to the file duration and calculated by the formula: https://www.w3.org/1998/Math/MathML"> DP = N Tx k l MEN   F x , https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where https://www.w3.org/1998/Math/MathML"> N TX - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> number of transmitted watermarked frames; https://www.w3.org/1998/Math/MathML"> l rax   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - length of the tested file in number of samples per file; k - number of information bits per block of BCH code. Fidelity was evaluated as Watermark-to-Signal https://www.w3.org/1998/Math/MathML"> WSR = 10 l g ⁡ ∑ j = 1 T SP     ∑ i = 1 N Sρ     X ij - S ij 2 ∑ j = 1 T SP     ∑ i = 1 N Sp     X ij 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where https://www.w3.org/1998/Math/MathML"> X ij , S ij https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - amplitude of spectrograms of dimension [Time, Frequency] https://www.w3.org/1998/Math/MathML"> = T SP , N SP https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Table 3. Data payload and fidelity versus step size and threshold factor Step size Threshold factor Data payload, bps Fidelity, dB 0.25 0.5 102 https://www.w3.org/1998/Math/MathML"> - 49.04 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 1 136 https://www.w3.org/1998/Math/MathML"> - 41.36 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2 255 https://www.w3.org/1998/Math/MathML"> - 31.57 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 4 356 https://www.w3.org/1998/Math/MathML"> - 25.12 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.5 0.5 102 https://www.w3.org/1998/Math/MathML"> - 42.16 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 1 136 https://www.w3.org/1998/Math/MathML"> - 34.82 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2 272 https://www.w3.org/1998/Math/MathML"> - 24.56 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 4 365 https://www.w3.org/1998/Math/MathML"> - 18.87 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 1 0.5 102 https://www.w3.org/1998/Math/MathML"> - 36.56 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 1 144 https://www.w3.org/1998/Math/MathML"> - 28.5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2 297 https://www.w3.org/1998/Math/MathML"> - 18.71 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 4 399 https://www.w3.org/1998/Math/MathML"> - 12.17 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2 0.5 110 https://www.w3.org/1998/Math/MathML"> - 28.97 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 1 178 https://www.w3.org/1998/Math/MathML"> - 20.19 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2 322 https://www.w3.org/1998/Math/MathML"> - 11.85 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 4 450 https://www.w3.org/1998/Math/MathML"> - 6.05 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Spectrograms were computed in accordance of ITU Recommendation [11] by mapping the time signals to the time-frequency domain using a shortterm FFT with a Hann window of size 256 samples. Considering an acceptable level of speech signal degradation under proposals to WSR from [7] of magnitude https://www.w3.org/1998/Math/MathML"> - 20   d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or less the independent parameters Δ and h may be chosen from Table 3 for practical implementation. Other AW system parameters were taken as follows: vectors length https://www.w3.org/1998/Math/MathML"> L = 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , FFT dimension https://www.w3.org/1998/Math/MathML"> N = 512 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , number of embedded bits per frame https://www.w3.org/1998/Math/MathML"> n = 63 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , parameters of BCH code https://www.w3.org/1998/Math/MathML"> ( n , k , t ) = ( 63,30,6 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . AW robustness was evaluated as true-positive probability in the form of relation of received and correctly decoded watermarked frames to the total number of transmitted frames https://www.w3.org/1998/Math/MathML"> P cor = N RX / N TX https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Influence of channel attacks on is presented in the Table 4. Ratio in the frequency domain: Table 4. Probability of frame correct detection versus step size subjected to various channel attacks ** For the thresholds https://www.w3.org/1998/Math/MathML"> h = 2 / 0.5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> accordingly Specifications of variety channel attacks, the watermarked signal is subjected to, are shown below: 1 Resampling: The watermarked signal, originally sampled at https://www.w3.org/1998/Math/MathML"> F s = 8 k H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , was interpolated at 16 https://www.w3.org/1998/Math/MathML"> k H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , shifted by one sample and then restored back at https://www.w3.org/1998/Math/MathML"> 8 k H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Appropriate procedure interp https://www.w3.org/1998/Math/MathML"> ( s , 4 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2 MP3 compression https://www.w3.org/1998/Math/MathML"> 9.6 k b p s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> : The watermarked signal was compressed at the bitrate of https://www.w3.org/1998/Math/MathML"> 9.6 k b p s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and then decompressed back to wav format. 3 Compressing - Expanding (companding): The watermarked signal undergoes standard companding procedure according μ-law. lin2mu (s), mu2lin(y) 4 Filtering: The watermarked signal was passed through the passband Butterworth filter of order 2 and cutting frequencies https://www.w3.org/1998/Math/MathML"> 400   H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 2 k H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . butter ( https://www.w3.org/1998/Math/MathML"> 1 , . 1 0.5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , filter (bb, aa, s) 5 Additive White Gaussian Noise (AWGN): White Gaussian noise was added at the level measured for the whole signal fragment. awgn (s, SNR, ' measured' ) 6 Quantization: The watermarked signal was quantized by Q levels. https://www.w3.org/1998/Math/MathML"> 1 / Q https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> * round https://www.w3.org/1998/Math/MathML"> ( s * Q ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 7 Clipping: The watermarked signal was cut with saturation at levels https://www.w3.org/1998/Math/MathML"> ± 0.5 m a x | s | ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 8 Flat fading: The watermarked signal undergoes sinusoidal amplitude modulation with a modulation frequency of https://www.w3.org/1998/Math/MathML"> 3   H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and a modulation depth of 0.5. 9 Complex interference: A simultaneous influence of attacks https://www.w3.org/1998/Math/MathML"> ( 4 ) + ( 5 ) - 30   d B + ( 8 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> For channel attacks (1), (2) no robustness degradation was registered. In all experiments no false-negative errors were registered. Reasonably high level of false-positive errors is not meaningful for watermarking in AI application, because of repeatedly transmitted same watermark in the view of MMSI. Single true-positive watermark detection within https://www.w3.org/1998/Math/MathML"> ( 1 - 3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sec to consider identification successful is sufficient. Signalograms that illustrate asynchronous watermarking and influence channel attacks on its detection are shown in Fig. 4 for parameters https://www.w3.org/1998/Math/MathML"> Δ = 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , https://www.w3.org/1998/Math/MathML"> h = 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Peak-factor for the tested voice signal comes to https://www.w3.org/1998/Math/MathML"> 12.7   d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The total number of watermarked frames amounted to 17 , at that the data payload amounted to 63 watermarked (including 30 pure) bits per frame. An evident tendency of watermarked frames is placing them within pauses (intervals https://www.w3.org/1998/Math/MathML"> 1.8 - 2.1 s e c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 3.2 - 3.5 s e c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) and unvoiced phonemes (all the rest) as shown in Fig. 4 a). Companding attack No 3 from attack specification destroyed no watermarks and all 17 data packets were detected and correctly decoded. For more complicated situation against complex attack No 9: Filtering + additive noise https://www.w3.org/1998/Math/MathML"> ( - 30 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> d B ) + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> flat fading only 5 data blocks were restored. For AI implementation such outcome is quite accessible. Recommended parameters and related characteristics separately for VHF analog R/T identification and satellite hidden communication are shown in the Table 5. Requirements to watermark robustness in digital satellite channels may be reduced because the codec itself is responsible for stable communication. Therefore proposed hidden communication will be supported as long as the main link is possible. In particular the value of step size Δ and correcting strength t of https://www.w3.org/1998/Math/MathML"> B C H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> may be decreased in favor of data payload. Table 5. Recommended independent parameters and related characteristics VHF analog R/T identification Satellite hidden communication Independent parameters: 1;2 0.25;0.5 Step size Δ 2;4 Threshold factor h 0.5;1 512 FFT dimension N 512 https://www.w3.org/1998/Math/MathML"> ( 63,30,6 ) ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> BCH code https://www.w3.org/1998/Math/MathML"> ( n , k , t ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> ( 63,30,6 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> ( 63,36,5 ) ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> ( 63,39,4 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Vector length L 2 2 Related characteristics: https://www.w3.org/1998/Math/MathML"> 255 * … 365 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Data payload, bps 102…178 https://www.w3.org/1998/Math/MathML"> - 25 … - 19 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Fidelity, dB https://www.w3.org/1998/Math/MathML"> - 36 … - 20 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 64 Delay, msec 64 For BCH code https://www.w3.org/1998/Math/MathML"> ( 63,30,6 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 9. CONCLUSION Presented philosophy of watermarked radiotelephone terrestrial and satellite maritime communication gives new possibilities of enhancing navigational safety and security. The comprehensive design of AW system makes possible its application in analog and digital communication channel irrespective of radio installation already involved. A single hardware upgrading includes two electronic chips. One of them is placed directly into the handset at the transmitting part and another one is switched to standard audio output at the receiving part. No other invasions in operating radios and operational procedures are needed. Besides, the designed system is fully compatible with the installation without AW function. AW for VHF radiotelephone identification is exclusively appropriate for smart and addressed ship-to-ship and ship-to-shore with all priorities radiotelephony, especially taking into account obligatory watch on channel 16[12]. It is also helpful to monitor intentional and accidental violations of radiocommunication. AW application in digital satellite voice communication gives additional chances for hidden data communication for the sake of security. The proposed AW system has rather easy implementation because embedding/detection algorithms are based on standard FFT and BCH encoding/decoding procedures. All calculations are also suitable to vectorization. Figure 4. Watermarked audio signals and disposition of watermarked frames (black): a) before channel attacks and after channel attacks b) μ-law companding c) complex interference: Filtering + additive noise https://www.w3.org/1998/Math/MathML"> - 30   d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> + flat fading 10. REFERENCE [1] Automatic Transmission of the Identification of the Radiotelephone Station. COMSAR 16/7, Submitted by Poland, December 2011. [2] Proposals to Amend the Performance Standards for Shipborne VHF Radiotelephone Facilities. COMSAR 14/7/5, Submitted by the Republic of Korea, December 2009. [3] ETSI EN 300698-1. Radio telephone transmitters and receivers for the maritime mobile service operating in the VHF bands used on inland waterways; Part 1: Technical characteristics and methods of measurement. https://www.w3.org/1998/Math/MathML"> 50 p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . [4] K. Hofbauer, G. Kubin, W.Kleijn "Speech Watermarking for Analog Flat-Fading Bandpass Channels", IEEE Transactions on Audio, Speech and Language Processing, November 2008, Vol. 17, No. 8, pp. 1624 - 1637 [5] Shishkin A. V. "Identification of radiotelephony transmissions in VHF band of maritime radio communications", Radioelectronics and Communication Systems, November 2012, Vol. 55, No. 11, pp. 482-489 [6] Shishkin A. V., Koshevoy V.M. "Stealthy Information Transmission in the Terrestrial GMDSS Radiotelephone Communication", TransNav - International Journal on Marine Navigation and Safety of Sea Transportation, Vol. 7, No. 4, pp. 541-548,2013 [7] Vivekananda Bhat K, Indranil Sengupta, Abhijit Das "An adaptive audio watermarking based on the singular value decomposition in the wavelet domain". Digital Signal Processing, Volume 20, Issue 6, December 2010, Pages 1547-1558. Available at https://202.114.89.42/resource/pdf/5566.pdf 8] Gel'fand S. I., Pinsker M. S. "Coding for channel with random parameters" / S. I. Gel'fand, M. S. Pinsker // Problems of Control and Information Theory. - 1980. Vol. 9(1), pp. 19-31. [9] Morelos-Zaragoza R.H. The art of error correcting codes. John Wiley, 2006, 263 p [10] Operational procedures for the use of digital selectivecalling equipment in the maritime mobile service. RECOMMENDATION ITU-R M.541. [11] ITU-T Recommendation P.862: Perceptual evaluation of speech quality https://www.w3.org/1998/Math/MathML"> ( PESQ ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , International Telecommunication Union, 02/2001. [12] Brzoska S. "Advantages of Preservation of Obligatory Voice Communication on the VHF Radio Channel 16", TransNav - International Journal on Marine Navigation and Safety of Sea Transportation, Vol. 4, No. 2, pp. 137 141,2010 . Introduction to Inmarsat GEO Space and Ground Segments D.S. Ilcev Durban University of Technology (DUT), South Africa Abstract This article presents retrospective of development Inmarsat space and ground segments as a Geostationary Earth Orbit (GEO) satellite system with significant contribution to the modern maritime and other mobile satellite applications. The technical parameters and comparison of previous and new generations of Inmarsat GEO satellite constellations with their advantages and disadvantages are described. The choice and upgrading of a particular satellite configuration depends mainly on its mission objectives, development trends of satellite mobile service and applications, modernization of onboard equipment and characteristics of the satellite payloads. Each Inmarsat satellite provides global beam spacecraft antenna for global coverage covering approximately one-third of the Earth's surface (including land and sea) and spot beam coverages from an GEO nearly 36,000 kilometers above the Equator. In this orbit each satellite moves at exactly the same rate as the Earth rotates, so remaining in the same position relative to the Earth's surface. Fife generations of Inmarsat GEO satellite constellations, Inmarsat link budget, ground segment, ground networks, coordination and different control centres are introduced. 11. INTRODUCTION Inmarsat was established in 1979 known as the International Maritime Satellite Organization (Inmarsat) not-profit international organization, set up at the behest of the International Maritime Organization (IMO) and an UN body, for the purpose of establishing a satellite communications network for the commercial maritime community, ship management including, emergency, distress and safety applications. It began trading in 1982 and was used the acronym "Inmarsat", which operates and maintains the Inmarsat Ground Network (IGN) constellation of nine GEO satellites and many Mobile Earth Station (MES) and Land Earth Station (LES) terminals. The company has over 33 years experience in designing, implementing and operating innovative satellite communication networks and Mobile Satellite Communication (MSC) configurations. Inmarsat delivers its services through an IGN of about 260 partners in over 80 countries including some of the world's largest telecommunications companies and offers a portfolio of visionary Mobile Satellite Service including Fixed Satellite Service (FSS) via portable units for governments and enterprises requiring reliable voice, data and video communication on land, at sea or in the air, with over https://www.w3.org/1998/Math/MathML"> 98 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the Earth's surface (except the polar regions). Inmarsat also provides service in regions of developed and developing countries were there is no available service of Terrestrial Telecommunication Networks (TTN). The intent was to create a self-financing body, which would improve communications and other safety service according to the Safety of Life at Sea (SOLAS) Convention and IMO regulations and recommendations. The name was changed to International Mobile Satellite Organization (IMSO) when it began to provide services to road, rails, aircraft and portable users, but the acronym "Inmarsat" was kept. When the organization was converted into a private company in 1999 , the business was split into two parts: the bulk of the organization was converted into the commercial company, Inmarsat Plc, and a small group became the regulatory body, IMSO. In 2005 Apax Partners and Permira bought shares and the Company was also first listed on the London Stock Exchange in that year. In 2008 the USA-based Harbinger Capital owned https://www.w3.org/1998/Math/MathML"> 28 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the Company and one year later Inmarsat completed the acquisition of a https://www.w3.org/1998/Math/MathML"> 19 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> stake in SkyWave manufacturer. Thus, Inmarsat was the world's first international and nongovernmental Global Mobile Satellite Communication (GMSC) operator offering a mature range of modern communications services to maritime, land, aeronautical and semi-fixed users, such as Broadband Global Area Network (BGAN). The Inmarsat satellites are controlled from Inmarsat's headquarters in London, which is also home to Inmarsat Ventures and small IGO created to supervise the company's public service for the maritime community, known as Global Maritime Distress and Safety System (GMDSS), implemented with IMO, and aviation Air Traffic Control ATC/CNS implemented with ICAO. The keystone of the Inmarsat strategy is the current I-4 advanced satellite constellation, which from 2004 started to support the Inmarsat BGAN, mobile satellite data communications at up to https://www.w3.org/1998/Math/MathML"> 432   K b / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for Internet access, mobile multimedia via satellite and many other advanced applications https://www.w3.org/1998/Math/MathML"> [ 1,2 , 3 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Inmarsat [1] 12. INMARSAT SPACE SEGMENT For the first decade of Inmarsat's operations, the space constellation has been leased from Comsat (series of three Marisat satellites F1, F2 and F3), from ESA (series of two Marecs satellites A and B2) and from Intelsat (series of three Intelsat V-MCS A, B and D). These satellites were initially configured in three ocean regions: Atlantic Ocean region (AOR), Indian Ocean Region (IOR) and Pacific Ocean region (POR), each containing an operational satellite and at least one spare in-orbit. This satellite constellation is known as the first generation of the Inmarsat network. Inmarsat was not responsible for TT&C, but operations were controlled by Inmarsat Network Control Centre (NCC) in London. 12.1. Second and Third Generation of Inmarsat Satellite Constellation The previous space segment of Inmarsat network consisted in total four GEO I-3 and I-2 satellites. The main global beam of each satellite provides overlapping coverage of the whole surface of the Earth apart from the Poles and in this way it is possible to extend the reach of terrestrial wired and cellular networks to almost anywhere on Earth. Thus, a call from an Inmarsat Mobile Earth Station (MES) goes directly to the satellite overhead, which routes it back down to a Gateway on the ground called a Land Earth Station (LES). From there, the calls/messages are passed into the public phone of Terrestrial Telecommunication Network (TTN), data and Integrated Services Digital Network (ISDN) networks. The Inmarsat-3 satellites are backed up by a five Inmarsat- 3 and four Inmarsat-2. A key advantage of the Inmarsat-3 over their predecessors is their ability to generate a number of spot-beams as well as large global beams. Spot-beams concentrate extra power in areas of high demand and making it possible to supply standard services to smaller and simpler mobile terminals. In Table 1 is shown a list of the Inmarsat spacecraft of 1998/99 deployed for global coverage except the Poles. Table 1. Ocean Regions and Satellite Longitudes Satellite Status Atlantic (West and East), Indian and Pacific Ocean Regions Atlantic/AOR-W Atlantic/AOR-E Indian/IOR Pacific/POR https://www.w3.org/1998/Math/MathML"> 1 st   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Operational Inmarsat-2 F4 Inmarsat-3 F2 Inmarsat-3 F1 Inmarsat-3 F3 Position https://www.w3.org/1998/Math/MathML"> 54 ∘ W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 15.5 ∘ W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 63.9 ∘ E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 178.1 ∘ E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 2 nd   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Operational Inmarsat-3 F4 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Position https://www.w3.org/1998/Math/MathML"> 54 ∘ W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> In-Orbit Spare Inmarsat-2 F2 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Inmarsat-2 F3 Inmarsat-2 F1 Position https://www.w3.org/1998/Math/MathML"> 55 ∘ W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 65 ∘ E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 179 ∘ E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Moreover, the information list of current Inmarsat GEO satellite constellations is presented in the Inmarsat Maritime Communications Handbook (Issue 4 of 2002 ) and gives the same 1 st positions for operational satellites but in the event of a satellite failure the values change as follows: AORW at https://www.w3.org/1998/Math/MathML"> 98 ∘ W ; A O R - E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 25 ∘ E ; P O R https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 179 ∘ E ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> IOR (For Inmarsat-A, B, C and M ) at https://www.w3.org/1998/Math/MathML"> 109 ∘ E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and IOR (For Inmarsat-C, mini-M and Fleet) at https://www.w3.org/1998/Math/MathML"> 25 ∘ E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The Inmarsat organization bases its Earth coverage on a constellation of four prime GEO satellites covering in Figure 1. The coverage area for any satellite is defined as the area on the Earth's surface (sea, land or air), within which Line-of-Sight (LOS) communication can be made with the visible satellite. That means, if an Inmarsat MES terminal is located anywhere within a particular satellite coverage area and an antenna of MES is directed towards that satellite, it will be possible to communicate through that satellite with any LES that is also pointed at the same particular satellite. In Figure 2 is illustrated the footprints of global beam coverages projected onto the surface of the Earth from the four Inmarsat-3 GEO satellites in use for all mobile application. Thus, it should be noted that the recommended limit of latitudinal beam coverage is within the area between https://www.w3.org/1998/Math/MathML"> 75 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> North and South https://www.w3.org/1998/Math/MathML"> [ 2,3 , 4,5 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Figure 3. Inmarsat I-4 Spot-Beam Coverage for Digital Mobile Broadband - Courtesy of Prospect: by Inmarsat [6] The previous map presented in Figure 2 depicts coverage following completion of the satellite repositioning process. In the AOR-W region, Classic services were delivered via the I-4 satellite. Now the I-4 satellite over the Americas is activated, Classic services traffic in AOR-W has been transferred back to an I-3 satellite. As a result, there is reduced spot beam coverage in AOR-W, but Inmarsat will make best commercial efforts to increase the I-3 spot beam coverage so that it exceeds the original I-3 coverage. In Figure 3 is shown the global narrow spot-beam coverage of each Inmarsat-4 satellite for three ocean regions. Thus, I-4 satellites are covering three oceans with overlappings, which narrow beams vary in size with tend to be several hundred kilometers across. In Table 2 are presented the characteristics of 3 Inmarsat's generations. Therefore, I-4 satellites are covering Maritime service such as FleetPhone, Fleet 33/55/77 and FleetBroadband, Land service such as BGAN, IsatPhone, LandPhone, GAN and Mini-M, while for Aeronautical service are covering Aero-C, I, M, mini-M, Swift64 and SwiftBroadband. As a large percentage of the Earth's MSC requirements lies within this roaming area, the system is considered to possess a global coverage pattern. As well as a "global" beam covering a complete hemisphere, each satellite generates up to seven spot beams designed to increase the amount of communications capacity available in areas of high demand. Namely, the MSC services are delivered to ships, land vehicles (road and rail), aircraft, transportable and semi-fixed mobile terminals through the spot beams of the three Inmarsat-4 satellites https://www.w3.org/1998/Math/MathML"> [ 3,5 , 6,7 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In Figure 4 is illustrated Inmarsat I-4 global-beam network coverage following completion of the satellite-repositioning program, which ended on 24 February 2009. In such a way, to reflect the geographic locations covered by the satellites, Inmarsat refers to its three I-4 satellite regions as follows: I-4 Americas at position https://www.w3.org/1998/Math/MathML"> 98 ∘ W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , I-4 EMEA (Europe, Middle East, and Africa) at https://www.w3.org/1998/Math/MathML"> 25 ∘ E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> I - 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Asia-Pacific at https://www.w3.org/1998/Math/MathML"> 143.5 ∘ E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In Figure 4 is illustrated Inmarsat I-4 global-beam network coverage following completion of the satellite-repositioning program, which ended on 24 February 2009. In such a way, to reflect the geographic locations covered by the satellites, Inmarsat refers to its three I-4 satellite regions as follows: I-4 Americas at position https://www.w3.org/1998/Math/MathML"> 98 ∘ W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , I-4 EMEA (Europe, Middle East, and Africa) at https://www.w3.org/1998/Math/MathML"> 25 ∘ E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and I-4 Asia-Pacific at https://www.w3.org/1998/Math/MathML"> 143.5 ∘ E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In this sense, with its own three GEO satellite constellation the Inmarsat network provides the GMSC service, which in Article-3 of the Inmarsat convention is stated as: "The purpose of Inmarsat is to make provision for the space segment necessary for improving mobile maritime and, as practicable, aeronautical and land communication and as well as MSC service on other waters not part of the marine environment, thereby assisting in improving GMSC for distress and safety of life, communications for Air Traffic Service (ATS), the efficiency and management of transportation by sea, on land and in air and other mobile public correspondence services and radio determination capabilities". In such a way, the present spot-beam coverage concentrates extra power in areas of high demand as well as making it possible to supply standard service to smaller, simpler and less powerful mobile terminals. At this point, a key advantage of the Inmarsat-4 satellites over their predecessors is their ability to generate a great number of spot-beams as well as single large global beams. The coverage map of new forthcoming fifth generation of Inmarsat I- 5 spacecraft is shown in Figure 5, known as Global Xpress new Inmarsat I- 5 satellite constellation, which offers seamless global coverage with mobile broadband speeds of up to 50 https://www.w3.org/1998/Math/MathML"> M B / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for users in the government, maritime, land, energy and aeronautical sectors. Inmarsat is investing an estimated amount of 1.2 billion US$in the Global Xpress program, which includes launch costs https://www.w3.org/1998/Math/MathML"> [ 5,7 , 8,9 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Figure 13. 2.2 Second Generation of Inmarsat-2 Satellites Inmarsat operates a total of four 2 nd generation Inmarsat-2 birds launched in 1990/92 with a capacity equivalent to about 250 Inmarsat-A voice circuits. In fact, these four Inmarsat-2 satellites were built according to Inmarsat specifications by an international consortium headed by the firm known as Space and Communications Division of British Aerospace (now Matra Marconi Space). The Inmarsat-2 satellite design is based on the Eurostar three-axis-stabilized satellite platform with 10 years lifetime, shown in Figure 6 (A). At launch, each satellite weighed is https://www.w3.org/1998/Math/MathML"> 1,300 k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and had an initial in-orbit mass of https://www.w3.org/1998/Math/MathML"> 800 k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 1,200 watts of available power. Each communications payload provides two satellite transponders, which realize outbound ( C to L-band) and inbound (L to C-band) links with MES in the 6.4/1.5 and https://www.w3.org/1998/Math/MathML"> 1.6 / 3.6 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bands, respectively. So, the L-band EIRP is a minimum of https://www.w3.org/1998/Math/MathML"> 39 d B W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , while G/T for L-band is about https://www.w3.org/1998/Math/MathML"> - 6 d B / K https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for global satellite coverage. Each satellite's global beam covers roughly one-third of the Earth's surface. 14. 2.3 Third Generation of Inmarsat-3 Satellites The Lockheed Martin Astro Space is US-based Company that built the new spacecraft bus for next Inmarsat-3 generation, which is based on the GE Astro Space Series https://www.w3.org/1998/Math/MathML"> 4000,2.5 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> high and with a 3.2 radial envelope centered on a thrust cone. Matra Marconi Space built the communications payload, spacecraft antenna systems, repeater and other communications electronics. Thus, payload and solar arrays are mounted on N and S-facing panels. The L-band Receiver (Rx) and Transmitter (Tx) reflector arrays are mounted on E and W panels and are fed by an array with cupshaped elements. Furthermore, the navigation antenna is located on the Earth-facing panel. Table 3. Orbital Parameters of Inmarsat-3 Spacecraft Background Owner/Operator: Inmarsat Organization Present status: https://www.w3.org/1998/Math/MathML"> Orbital location: 64o East Altitude: About 36,000 Type of orbit: Inclined GEO Inclination angle: ± 2.7 o Number of satellites: 1 operational https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> Orbital location: 64o East Altitude: About 36,000 Type of orbit: Inclined GEO Inclination angle: ± 2.7 o Number of satellites: 1 operational https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> Orbital location: 64o East Altitude: About 36,000 Type of orbit: Inclined GEO Inclination angle: ± 2.7 o Number of satellites: 1 operational https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Orbital location: 64o East Altitude: About 36,000 Type of orbit: Inclined GEO Inclination angle: https://www.w3.org/1998/Math/MathML"> ± 2.7 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Number of satellites: 1 operational Altitude: Additional information: Other Ocean regions POR, AOR-W and AOR-E have 1 operational and 1 or 2 spare Inmarsat- 2 or 3 satellites Spacecraft https://www.w3.org/1998/Math/MathML"> Name of satellite: Inmarsat-3 F1 Launch date: 4 April, 1996 Launch vehicle: Atlas IIA Typical users: Maritime, Land and Aeronautic https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> Name of satellite: Inmarsat-3 F1 Launch date: 4 April, 1996 Launch vehicle: Atlas IIA Typical users: Maritime, Land and Aeronautic https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> Name of satellite: Inmarsat-3 F1 Launch date: 4 April, 1996 Launch vehicle: Atlas IIA Typical users: Maritime, Land and Aeronautic https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> Name of satellite: Inmarsat-3 F1 Launch date: 4 April, 1996 Launch vehicle: Atlas IIA Typical users: Maritime, Land and Aeronautic https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> Name of satellite: Inmarsat-3 F1 Launch date: 4 April, 1996 Launch vehicle: Atlas IIA Typical users: Maritime, Land and Aeronautic https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> Name of satellite: Inmarsat-3 F1 Launch date: 4 April, 1996 Launch vehicle: Atlas IIA Typical users: Maritime, Land and Aeronautic https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> Name of satellite: Inmarsat-3 F1 Launch date: 4 April, 1996 Launch vehicle: Atlas IIA Typical users: Maritime, Land and Aeronautic https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> Name of satellite: Inmarsat-3 F1 Launch date: 4 April, 1996 Launch vehicle: Atlas IIA Typical users: Maritime, Land and Aeronautic https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> Name of satellite: Inmarsat-3 F1 Launch date: 4 April, 1996 Launch vehicle: Atlas IIA Typical users: Maritime, Land and Aeronautic https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> Name of satellite: Inmarsat-3 F1 Launch date: 4 April, 1996 Launch vehicle: Atlas IIA Typical users: Maritime, Land and Aeronautic https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> b) Navigation: L1 1.5 \& C-band 6.4 / 3.6 G H z Multiple access: TDM/TDMA Modulation: BPSK, O-QPSK, FEC Transponder type: L-C/C-L \& L1-C-band Number of transponders: 1 L & C - band Channel bit rate: From 600 b / s to 24 K b / s Channel capacity: About 2000 voice circuits https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> b) Navigation: L1 1.5 \& C-band 6.4 / 3.6 G H z Multiple access: TDM/TDMA Modulation: BPSK, O-QPSK, FEC Transponder type: L - C / C - L & L 1 - C - b and Number of transponders: L \& C-band Channel bit rate: From 600 b / s to 24 K b / s Channel capacity: About 2000 voice circuits https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> b) Navigation: L1 1.5 \& C-band 6.4 / 3.6 G H z Multiple access: TDM/TDMA Modulation: BPSK, O-QPSK, FEC Transponder type: L - C / C - L & L 1 - C - b and Number of transponders: L \& C-band Channel bit rate: From 600 b / s to 24 K b / s Channel capacity: About 2000 voice circuits https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> b) Navigation: L1 1.5 \& C-band 6.4 / 3.6 G H z Multiple access: TDM/TDMA Modulation: BPSK, O-QPSK, FEC Transponder type: L - C / C - L & L 1 - C - b and Number of transponders: L \& C-band Channel bit rate: From 600 b / s to 24 K b / s Channel capacity: About 2000 voice circuits https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> b) Navigation: L1 1.5 \& C-band 6.4 / 3.6 G H z Multiple access: TDM/TDMA Modulation: BPSK, O-QPSK, FEC Transponder type: L - C / C - L & L 1 - C - b and Number of transponders: L \& C-band Channel bit rate: From 600 b / s to 24 K b / s Channel capacity: About 2000 voice circuits https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> b) Navigation: L1 1.5 \& C-band 6.4 / 3.6 G H z Multiple access: TDM/TDMA Modulation: BPSK, O-QPSK, FEC Transponder type: L - C / C - L & L 1 - C - b and Number of transponders: L \& C-band Channel bit rate: From 600 b / s to 24 K b / s Channel capacity: About 2000 voice circuits https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> b) Navigation: L1 1.5 \& C-band 6.4 / 3.6 G H z Multiple access: TDM/TDMA Modulation: BPSK, O-QPSK, FEC Transponder type: L - C / C - L & L 1 - C - b and Number of transponders: L \& C-band Channel bit rate: From 600 b / s to 24 K b / s Channel capacity: About 2000 voice circuits https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> L-L https://www.w3.org/1998/Math/MathML"> 1 M H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; C-C 9 MHz Channel polarization: L-band RHCP; C-band LHCP & RHCPEIRP. The tremendous advantage of the Inmarsat-3 over previous satellites is their ability to concentrate power on particular areas of high traffic within the footprint. Each satellite utilizes a maximum of seven spot beams and one global beam. In such a way, the number of spot beams will be chosen according to traffic demands. In addition, these new satellites can re-use portions of the L-band frequency for nonadjacent spot beams coverage, effectively doubling the capacity of the satellite. Each satellite weighs about https://www.w3.org/1998/Math/MathML"> 2,066 k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at launch, compared to https://www.w3.org/1998/Math/MathML"> 1,300 k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for an Inmarsat-2 satellite. However, the Inmarsat I-3 satellite produces up to https://www.w3.org/1998/Math/MathML"> 48 d B W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of EIRP, a measure of how much signal strength a satellite can concentrate on its service area coverage. All other parameters of Inmarsat-3 F1 satellite are presented The main mission spacecraft onboard payloads of Inmarsat-3 are the communication transponders on both C and L-band and are the frequency-translated by the transponders for the downlink within the same band, shown in Figure 6 (B). The uplink signal is rebroadcast to users within each ocean coverage and spot beam footprints. As a secondary payload, Inmarsat-3 has the navigation transponders that provide the WAAS capability of Augmentation CNS capabilities. Two frequencies, L1 on https://www.w3.org/1998/Math/MathML"> 1.57542 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and C-band on https://www.w3.org/1998/Math/MathML"> 3.6 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , are used to allow correction The WAAS signal will be broadcast to the users at Ll frequency, the same as GPS or GLONASS. the data received by the satellite and data being broadcast to mobile users is also down linked back to the control site in the C-band. In fact, the https://www.w3.org/1998/Math/MathML"> 6.4 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> L-band repeaters is power-limited to ensure that the navigation signal can never interfere with the GPS 2.4 Fourth Generation of Inmarsat-4 Satellites Responding to the growing demands from all worldwide and it will be compatible with third generation https://www.w3.org/1998/Math/MathML"> ( 3 G / 4 G ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cellular systems. Three Inmarsat I-4 F1 satellite launched March https://www.w3.org/1998/Math/MathML"> 11 th 2005 , I - 4 F 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> launched November https://www.w3.org/1998/Math/MathML"> 8 th 2005 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and I-4 F3 anticipated launch in 2007 (POR) subject to business case and successful service using IOR and AOR. All three spacecraft have the advanced technology to reduce service costs by https://www.w3.org/1998/Math/MathML"> 75 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , compared to existing Inmarsat-M4 charges. They will be 100 times more powerful than the present generation and BGAN will provide at least 10 times as much capacity as today's network. The spacecraft will be built in the UK; the bus will be assembled in Stevenage and the payload in Portsmouth. The two sections will be united in France, together with the US-built antenna and German-built solar arrays. The Inmarsat BGAN was later used as an example in order to be designed new maritime broadband known as a FleetBroadband and new aeronautical broadband known as a SwiftBroadband. However, Inmarsat GMSC service using current Inmarsat I-4 spacecraft is trusted with Maritime and Aeronautical commercial distress and safety services through compliance with IMO and ICAO requirements overseen by IMSO https://www.w3.org/1998/Math/MathML"> [ 5,7 , 10,11 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 15. 2.5 Fifth Generation of Inmarsat-5 Satellites Inmarsat has contracted Boeing, the US aerospace company to build a new Inmarsat- 5 constellation, for 1.2 billion US$, to provide global broadband network called Inmarsat Global Xpress. Boeing will construct three Inmarsat-5 (I-5) satellites based on its https://www.w3.org/1998/Math/MathML"> 702 H P https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> spacecraft platform, shown in Figure 7 (B). The first satellite was scheduled for 2013 , with full global coverage expected by the end of 2014 . Thus, this spacecraft will break new ground by transmitting in a portion of the radio spectrum never before utilized by the commercial operator of a global satellite system, which will be the extremely high radio frequency Ka-band. Each I-5 beard will carry a payload of https://www.w3.org/1998/Math/MathML"> 89 K a - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> band coverage beams capable of flexing capacity across the globe and enabling Inmarsat network to adapt to shifting subscriber usage patterns over their projected lifetime of 15 years. The Inmarsat future Global Xpress network will take advantage of the additional bandwidth available in the Ka-band to offer download rates up to https://www.w3.org/1998/Math/MathML"> 50 M b / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and upload speeds of https://www.w3.org/1998/Math/MathML"> 5 M b / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> from all mobile user terminals as small as 60 centimeters. New I- 5 spacecraft will operate independently from the L-band satellites offering complementary services for a wide range of mobile and fixed solutions. The new satellites will join Inmarsat's fleet of https://www.w3.org/1998/Math/MathML"> 11 G E O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> satellites in total that provide a wide range of voice, data and video (VDV) transmissions through an established global distributors and service providers. Leveraging Boeing's big expertise in government applications I-5 satellites will provide an array of secure voice and high-speed communications applications between land, sea and air services and multinational coalitions https://www.w3.org/1998/Math/MathML"> [ 5,7 , 12,13 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 16. INMARSAT MSC LINK BUDGET The Inmarsat satellites link budget analysis forms the cornerstone of the space system design. Link budgets are performed in order to analyze the critical factors in the transmission chain and to optimize the performance characteristics, such as transmission power, bit rate and so on, in order to ensure that a given target quality of service can be achieved. The sample a of maritime link budget for the link MESto-GEO at https://www.w3.org/1998/Math/MathML"> 1.64 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and from the LES-to-GEO at https://www.w3.org/1998/Math/MathML"> 6.42 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and in the reverse direction for the link GEO-to-LES at https://www.w3.org/1998/Math/MathML"> 4.2 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and GEO-to-MES at 1.5 https://www.w3.org/1998/Math/MathML"> G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is shown in Table 4 . The MES terminal is considered as any Inmarsat installation, which G/T is https://www.w3.org/1998/Math/MathML"> - 4   d B / K https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The up and downlink budget for https://www.w3.org/1998/Math/MathML"> C / N 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are fairly standard except can be noted that: https://www.w3.org/1998/Math/MathML"> C / N 0 = E I R P - F S L - L f + G / T - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> K, where https://www.w3.org/1998/Math/MathML"> F S L = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Free Space Loss; https://www.w3.org/1998/Math/MathML"> L f = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> fixed losses made up of antenna misalignment of the receiver; and K= Boltzmann Constant in logarithmic form ( https://www.w3.org/1998/Math/MathML"> 228.6 d B W / H z / K ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The intermodulation on board the spacecraft is given as follows: the total intermodulation noise in the https://www.w3.org/1998/Math/MathML"> 7.5 M H z ( 68.8 d B H z ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> transponder is https://www.w3.org/1998/Math/MathML"> 24 d B W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The subtraction https://www.w3.org/1998/Math/MathML"> 24 - 68.8 = - 44.8 d B W / H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , so the carrier to intermodulation noise https://www.w3.org/1998/Math/MathML"> C / N o L M = 18 d B W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - 44.8 d B W / H z = 62.8   d B - H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Thus, the required https://www.w3.org/1998/Math/MathML"> C / N ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> has to be https://www.w3.org/1998/Math/MathML"> 52.5   d B - H z [ 1,2 , 5,14 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 17. INMARSAT GROUND SEGMENT AND NETWORKS The Inmarsat ground segment comprises a network of LES, which are managed by different LES operators, Network Coordination Stations (NCS) and Network Control Centre (NCC). The major part of the ground segment and other networks are mobile subscribers or MES, which can be Ship Earth Station (SES), Vehicle Earth Station (VES) or Aircraft Earth Station (AES). Each LES satellite operator provides a reliable transmission link between satellite network and TTN, capable of handling many types of calls to and from MES terminals simultaneously over the Inmarsat networks. The Inmarsat network is providing many types of Mobile Satellite Services (MSS): maritime, land and aeronautical, such as Voice, Fax, L/M/HSD (Low/Medium/High Speed Data) via TTN, which I4 ground segment is illustrated in Figure 8 . In addition, the ground segment containing LES, Telemetry, Tracking & Command (TT&C), NCS https://www.w3.org/1998/Math/MathML"> N C C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Satellite Control Centre https://www.w3.org/1998/Math/MathML"> ( S C C ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Search & Rescue Centre and different MES terminals. 17.1. Inmarsat Mobile Earth Station (MES) Solutions An MES is an RF device installed on board different mobiles, such as SES, VES, AES and Transportable Earth Station (TES), or it can be installed in a fixed location in maritime or land-based environments, indoor or outdoor, public payphones, on board mobiles and in suburban, rural and remote locations including SCADA applications. Inmarsat does not manufacture such equipment itself but permits manufacturers to produce models, which are type- approved to standards that have been set by Inmarsat and other international bodies, such as IMO, ICAO and the International Electrotechnical Commission (IEC). Therefore, only type-approved terminals are permitted to communicate via Inmarsat's space and ground segments. At this point, all types of MES provide different communication services in both mobile-to-ground and ground-to-mobile direction and inter-mobile communications. The list of MES terminals, types of service and access codes and the countries in which they are registered are given in Inmarsat Operational Handbooks, in the Admiralty List of Radio and Satellite Services, in the ITU list of Ship Stations, and in SITA and ARINC list of Aircraft Stations. The Maritime MSS (MMSS) is a service in which MES is fitted onboard merchant or military ships, floating objects, rigs or offshore constructions, hovercrafts and survival craft stations providing commercial, logistics, tactical, defense and safety communications. The ship's Emergency Position Indicating Radio Beacon (EPIRB) terminal, either portable or fixed onboard may also participate in this service. The EPIRB is a special MES in the GMDSS, the emission of which is intended to facilitate urgent SAR operation for vessels in distress. The MMSS service enables mobile satellite links between LES and SES, between two or more SES and/or between associated ships and other satellite communications stations in all positions at sea or in ports. The SES is a mobile Earth station in the MMSS capable of surface movement at sea within the geographical limits of a country or continent. Thus, in distinction from conventional maritime communications, a ship fitted with SES in or near a port may operate with LES or other SES terminals in cases of distress and commercial operations https://www.w3.org/1998/Math/MathML"> [ 2,3 , 5,13 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 17.2. Inmarsat Land Earth Stations (LES) The LES terminal is a powerful land-based receiving and transmitting station serving in a GMSC system. The LES infrastructure is fixed on the ground, and so it can serve FSS as well, but cannot be part of FSS. In a more precise sense, every LES is a part of MSS network, although it has a fixed location and can provide https://www.w3.org/1998/Math/MathML"> F S S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Some LES, such as Goonhilly, provide widely fixed satellite links for FSS and consequently, the Inmarsat MSS network is a small part of the overall LES providing service for maritime and other mobile applications. Each LES in the IGN is owned and operated by an Inmarsat Signatory with the mission to provide a range of services to all types of MES. There are more than 40 LES terminals located in 30 countries around the globe but usually in the Northern Hemisphere, which is a small anomaly. The MES operator and shore subscribers can choose the most suitable LES, as long as they are within the same Ocean Region. The fundamental requirement for each Inmarsat LES terminal with Antenna Control and Signaling Equipment (ACSE) is that it be capable of reliable communications with all MES terminals, which block diagram is shown in Figure 9. There are two major types of Inmarsat LES: Coast Earth Station (CES) for maritime and land mobile applications, such as SES and VES standards, and Ground Erath Station (GES) for aeronautical mobile applications providing service to all AES standards. The list of LES terminals, types of service and access codes, the countries in which they are based and Ocean Region of operation are given in Inmarsat Operational Handbooks, in the Admiralty List of Radio and Satellite Services, in the ITU list of Coast Stations and in the SITA and ARINC documentations. The technical side of typical mobile LES (CES and GES) consists in three main features: the antenna system (left), the communication RF equipment (between Feed and https://www.w3.org/1998/Math/MathML"> A C S E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) and ACSE unit (right), as illustrated in Figure 9 . The CES is a maritime Earth station located at a specified fixed point on the coast to provide a feeder link for MMSS. The SES is a maritime Earth station fixed on board ships or other floating objects, which can provide communications links with subscribers onshore via CES and spacecraft. The ship on scene radiocommunications and alert service performs a distress and safety service in the MMSS between one or more https://www.w3.org/1998/Math/MathML"> S E S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and CES, or between two or more nearby SES, or between SES and Rescue Coordination Centre (RCC), or between portable or floating EPIRB and ground Local User Terminal (LUT) stations serving in the Cospas-Sarsat SAR satellite network in which alert messages are useful to those concerned with the movement and position of ships and of ships in distress. Antenna System - A typical LES antenna for an entire IGN would be a Cassegrain structure with a dish reflector of about https://www.w3.org/1998/Math/MathML"> 14   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> diameter. Each LES can have a minimum of one operational and one spare antenna communication system in order to continue transmissions during maintenance. Some LES terminals have more than two operational antennas, which depends on the Ocean Region covered and the services provided. The antenna operates in both the L and C-band to and from the satellite, with gain requirements of https://www.w3.org/1998/Math/MathML"> 50.5 d B i https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 29.5 d B i https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , respectively. It is designed to withstand high wind speeds up to 60 m/h in its operational attitude and https://www.w3.org/1998/Math/MathML"> 120   m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> when stowed at 900 and the parabolic dish is steerable https://www.w3.org/1998/Math/MathML"> ± 135 o https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in azimuth and 0 to https://www.w3.org/1998/Math/MathML"> 90 o https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in elevation angle. Tracking is either by automatic program control or operator initiated. An antenna tracking accuracy of 0.010 r.m.s. and a repositioning velocity of https://www.w3.org/1998/Math/MathML"> 10   s - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> would be typical parameters for such a dish. RF and base band processing hardware design varies greatly with LES design and requirements. In the other words, a single antenna may be used to transmit and receive L-band as well as the C-band signals or the employment of a separate L-band antenna avoids the need for a relatively complex feed system (to combine and separate the outgoing and incoming L-band and C band signals) but this advantage must be weighed against the cost of procuring and installing a second antenna. Communication RF Equipment - The radio RF equipment is situated inside the LES building and must be able to operate in Tx and Rx L-band links to monitor the MSC L-band channel and respond to requests for frequency allocations by the https://www.w3.org/1998/Math/MathML"> N C S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; to verify signal performance by loop testing between satellite and LES and to receive the C-to-L Automatic Frequency Control (AFC). The AFC provides Tx and Rx direction control, which helps to keep MES as simple and as cheap as is practicable. A complete test of the LES equipment can be carried out without the cooperation of the MES because a separate test terminal is provided at each LES for this purpose. The Inmarsat system requires https://www.w3.org/1998/Math/MathML"> A F C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to correct for Doppler shift (caused by inclination of the GEO) and errors in frequency translation in the satellite and LES. The total frequency shift from this cause without https://www.w3.org/1998/Math/MathML"> A F C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> could be more than https://www.w3.org/1998/Math/MathML"> 50 k H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and thus is of the same order as the spacing between the Narrow Band Frequency Modulation (NBFM) channels and would be enough to cause failure of the system. The https://www.w3.org/1998/Math/MathML"> A F C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> reduces the RF shift to a few hundred hertz by comparing pilot carriers transmitted via the satellite with reference oscillators at the LES and using the difference signals to control the RF of the local oscillator associated with the up and down converter. A pilot transmitted at C and received at L-band is used to control the up converter and thus offset the frequencies of the operational carriers to compensate for Doppler shift and satellite frequency translation errors in the ground-to-mobile direction. Similarly, a pilot transmitted at L and received at C-band controls the down converter and corrects for Doppler shift and errors in translation in the mobile-to-ground direction. All RF errors are corrected except those arising from the frequency instability of the MES up and down converter and Doppler shift resulting from the relative velocities of satellite and MES. ACSE - This Antenna Control and Signaling Equipment (ACSE) is part of each LES, whose principal purpose is to recognize requests for calls sent by MES, to set and release. This requires response to and initiation of in-band and out-bands signaling over the GEO satellite and the terrestrial path. The next ACSE tasks are to recognize distress calls sent by MES and preempt channels for them when necessary, to check that MES are on the list of authorized users and to bar calls from or to unauthorized MES, to switch voice circuits between TTN circuit and the LES FM channel modem, to switch Telex circuits between TTN channels and the Time Division Multiple/TDM Access (TDM/TDMA) time slots, to determine https://www.w3.org/1998/Math/MathML"> T x / R x https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> frequencies used by the FM channel unit according to the channel allocations made by the https://www.w3.org/1998/Math/MathML"> N C S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , to allocate TDM/TDMA time slots and to collect data statistics for billings, international accountings (for transit calls), traffic analyses, management and maintenance purposes, etc. The ACSE block is sometimes specified to include all the communication equipment of LES terminal other than RF and IF equipment, such as modulators and demodulators, data and voice channels, RF assignments to MES, line control subsystem, system control processor, and etc. The MSC services offered by an LES vary depending upon the complexity of the station selected, such as two-way voice including Fax/Paging, Telex, all data rate, Video, Global Are Network (GAN) - Internet, Web and Mobile Emergency services (Distress, Urgency, Safety and Medical assistance calls). At this point, multiplexing as a number of communication channels onto a single satellite link become possible by using duplex High Speed Data (HSD), such as multiplexing deploying six communication channels onto a single satellite connection through the Inmarsat duplex HSD service, shown in Figure 10 https://www.w3.org/1998/Math/MathML"> [ 1,2 , 5,13 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The maritime and other mobile configuration of IGN is applied to each of the four or three I-4 Ocean Regions for setting up MSC channels for ship-toground calls and vice versa, shore-to-ships calls. The same scheme can be implemented for any other MES configuration of mobile-to-ground calls, such as for land and aeronautical applications. Each MES has always to be tuned to the Common Signaling Channel (CSC) and to listen for assignments Requesting Channel https://www.w3.org/1998/Math/MathML"> ( R C ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , when is not engaged in passing traffic, namely when MES is an idle state, while each LES also watches the CSC to receive their channel assignments. The CSC is also referred to as TDM0 and is the origin of all traffic. The IGN is interfaced to the TTN as a Gateway to all fixed subscribers, shown in Figure 11. 18. 5.1 Network Coordination Stations (NCS) The Inmarsat system uses four NCS, one in each Ocean Region separate for each standard, to monitor and control MSC traffic within the region. Usually some LES perform dual services and when required to be specifically identified, the LES serving as an https://www.w3.org/1998/Math/MathML"> N C S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or Standby NCS will be referred as a collocated station. Hence, the NCS is involved in monitoring and control functions and in setting up calls between MES and LES, which is shown in Figure 11. The illustration shows in general terms how the NCS responds to a request from an MES (SES) for a communication channel, by assigning a channel to which both the MES and LES (CES) operator must tune for the call to proceed. Therefore, an LES serving as the NCS or Standby NCS terminals shall comply with all the technical requirements applicable to any Inmarsat standard LES and shall normally process its own calls in the same manner as a normal LES. In addition, the ground station serving as the NCS terminal shall perform the following necessary conditions for the important functions of IGN system: 1 Transmits continuously signals on a special channel known as an CSC at https://www.w3.org/1998/Math/MathML"> 6 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> L-band; 2 Accepts incoming request for Tlg (telegraphy) assignment MSG from all LES and re-broadcasts it to MES on the CSC; 3 Accepts Tel and HSD channel request-forassignment messages from all LES in IGN and makes Tel and HSD channel assignment via the common TDM channel; 4 Maintains a Tel and HSD channel-activity list that indicates which channels are in use as well as the LES and MES using each channel; 5 Determines if an addressed MES is busy with another call; 6 Clears a telephone call in progress if necessary to service an SOS priority request; and 7 Maintains a record of https://www.w3.org/1998/Math/MathML"> R C , C S C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and satellite https://www.w3.org/1998/Math/MathML"> T e l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> channel used for the IGN terminal's analysis purposes. Furthermore, NCS terminal shall also change to the Alternative Common TDM RF of https://www.w3.org/1998/Math/MathML"> 6 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for Inmarsat I-4 satellite, Tx transponder load control carriers and facilitating measurements of RF signals at both C and L-band from the satellite. For these functions to be performed, an MES Rx must initially be synchronized to the NCS common channel and logged-in to the NCS for its Ocean Region, either automatically or manually at the https://www.w3.org/1998/Math/MathML"> M E S ⁡ [ 1,2 , 5,14 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Figure 12. Inmarsat L-band GMSC Network Courtesy of Manual: ALRS [15] 19. 5.2 Network Control Centre (NCC) The Inmarsat NCC is located in the Inmarsat Headquarters building in London. It monitors, coordinates and controls the operational activities of all satellites (payload and antennas) and makes it possible to transfer operational information throughout the Network and via worldwide TTN routes, data between the https://www.w3.org/1998/Math/MathML"> N C C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in each of the 4 Ocean Regions, see Figure 8 . The NCC can send system messages via one or all of the NCS to inform the MES in their Ocean Regions of news relevant to any Inmarsat standards. It controls characteristics of the space segment throughout TT&C stations located in different countries; realizes all plans for new technical solutions and conducts development of the entire system; controls functions of current and newly introduced MES and LES and provides information about all MES, LES, NCS and the working condition of the entire Inmarsat system. 20. 5.3 Satellite Control Centre https://www.w3.org/1998/Math/MathML"> ( SCC ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Whereas the https://www.w3.org/1998/Math/MathML"> N C C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is crucial to the MSC service management, the SCC located in London at Inmarsat House is crucial to spacecraft management and functions of station-keeping and https://www.w3.org/1998/Math/MathML"> T T & C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , illustrated in Figure 8. All data to and from the https://www.w3.org/1998/Math/MathML"> S C C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is routed over worldwide TTN or tracking stations, which also provide backup capacity if required. The TT&C LES terminals are equipped with VHF, C and L-band for controlling spacecraft in all four Ocean Regions. Data on the status of the nine Inmarsat satellites is supplied to the SCC by four TT&C stations located at Fucino (Italy), Beijing (China), Lake Cowichan and Pennant Point in western and eastern Canada and there is also a back-up station at Eik in Norway. Thus, this service provides TT&C, i.e., operational status of spacecraft subsystems and payload, such as transponder signals; decoders and converters; temperature of all equipment and surface; diagnostics on all electrical functions; satellite orientation in space; situation of attitude control fuel; telemetry of process decoder and Rx beacons and provides tracking and control of all parameters during launch of satellite. 21. 5.4 Rescue Coordination Centers (RCC) As the name implies, RCC are used to assist with SAR in distress situations for maritime and aeronautical applications, shown in Figure 8 . Namely, extensive MSC links provide end-to-end connection between the vessel or airplane in distress and competent rescue authorities. Because of the very high priority status accorded to distress alerts and the use of automatic signaling systems, this direct connection linking is rapidly established, usually within only a few seconds. Comprehensive MSC systems link an individual RCC site and can have LES, MCC or LUT. When an RCC receives an original distress alert (SOS or MAYDAY) via one of these stations, it will relay details of the alert to SAR units and to other ships (if the distress is at sea) within the general area of the reported distress. Manual: ALRS [15] Hence this relayed message should provide the position and any other relevant information of position and any other relevant information of practical use in rescue operations. The RCC however, appropriately called First https://www.w3.org/1998/Math/MathML"> R C C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , assumes responsibility for all further on-scene coordination responsibility for all further on-scene coordination initial responsibility may be transferred to another initial responsibility may be transferred to another RCC terminal, which may be in a better position to generally involved in subsequent SAR team coordinating communications, such as between the coordinating communications, such as between the Coordinating Surface Search (ship or helicopter), Coordinating Surface Search (ship or helicopter), of the distress incident. 22. 5.5 Terrestrial Telecommunications Network The Terrestrial Telecommunications Network (TTN) operators are usually Inmarsat Signatories and can be PTT (Telecom) or any government or private TTN providing landline public Tel and Tlx service. The TTN shore operators enable interface of IGN on their landline infrastructure for voice, Fax, Tlx, Low, Medium and High Speed data (LSD/MSD/HSD) and video services, which Inmarsat Mobile Network (IMN) is presented in Figure 12. Each CES or GES as a part of initial Lband IMN has facilities to interface telephone, facsimile, low/medium/high speed data and telex networks of the TTN. On the other hand, IMN is providing services for maritime, land, aeronautical, personal, military, offshore and semi-fixed applications. Thus, the new Inmarsat HSD service enables connections to the TTN sites and other infrastructures, such as ISDN, PSDN, PSTN, Leased Lines, Data Network (X.25, X.75 and X.400), Private Data Networks, ATC Network, and etc. As stated before, the existing L-band Inmarsat service is providing digital transmission using mobile broadband, such as FleetBroadband for maritime and SwiftBroadband for aeronautical applications throughout current I-4 and future I-5 spacecraft. In addition, the new projected Ka-band Inmarsat service will start with mobile VSAT broadband service via I-5 spacecraft, illustrated in Figure 13 . The mobile Global Broadband Satellite System (GBSS) is recently introduced as a modern mobile and maritime VSAT networks, equipment and DVBRCS technique https://www.w3.org/1998/Math/MathML"> [ 2,5 , 12,15 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 23. CONCLUSION The Inmarsat space and ground segments have great significance with regard to satellite use for maritime and other MSS applications. Here are introduced very important context of fundamental contribution in development advanced Inmarsat satellite constellations, coverages, spot networks and the principal parameters that describe the new deployments of modern communication service for maritime and other mobile applications. 24. REFERENCES [1] Inmarsat, " Maritime Handbook" London, 2002. [2] Ilcev D. S. "Global Mobile Satellite Communications for Maritime, Land and Aeronautical Applications", Springer, Boston, 2005. [3] Zhilin V.A., "Mezhdunarodnaya sputnikova sistema morskoy svyazi - Inmarsat", Sudostroenie, Leningrad, 1988. [4] Inmarsat, "Inmarsat I-3 Global Coverage Map", Prospect, London, 2000. [5 Ilcev D.S., "Global Mobile Communications, Navigation and Surveillance (CNS)", Manual, DUT, Durban 2014 [www.dut.ac.za/space_science]. [6] Inmarsat, "Inmarsat I-4 Global Coverage Map for GMSC", Prospect, London, 2010. [7] Ilcev D. S. "Global Aeronautical Communications, Navigation and Surveillance (CNS)", Volume 1 & 2, AIAA, Reston, 2013. [8] Inmarsat, "Inmarsat I-5 Spot-Beam Coverage Map for Digital Mobile Broadband", London, 2012. [9] Inmarsat, "Global Mobile Communications Solutions", London 2001 [10] Acerov A.M. & Other, "Morskaya radiosvyaz i radionavigaciya", Transport, Moskva, 1987 [11] Novik L.I. & Other, "Sputnikovaya svyaz na more",Sudostroenie, Leningrad, 1987 . Sudostroenie, Leningrad, 1987 [12] Gallagher B., "Never Beyond Reach", Inmarsat, London,1989 , [13] Dalgleish D.I., "An Introduction to Satellite Communications", IEE, London, 1989. [14] Kantor L.Y. & Other, "Sputnikovaya svyaz i problema geostacionarnoy orbiti", Radio i svyaz, Moskva, 1988. [15] ALRS, "GMDSS" - Volume 5, Admiralty List of Radio Signals, Taunton, 1999. Integration of Radio and Satellite Automatic Identification System for D.S. Ilcev Durban University of Technology (DUT), South Africa Abstract This paper introduces the main technical characteristics and integration of current Radio and new Automatic Identification System (AIS) as more reliable solution for enhanced tracking and detecting systems for maritime applications. The technical parameters and comparison of current Radio AIS (R-AIS) and new developed Satellite AIS (S-AIS) with their advantages and disadvantages are described. The possibility in upgrading of a particular AIS configuration depends mainly on its mission objectives, development trends of radio and satellite mobile tracking and surveillance service, modernization of onboard and coastal equipment and characteristics of the satellite payloads for S-AIS. The R-AIS network provides local coverage in coastal waters of VHF-band range, however new S-AIS will be able to provide global beam coverage using Low Earth Orbit (LEO) or even Geostationary Earth Orbit (GEO) spacecraft. In addition, The R-AIS network and its classes, basic technical details of AIS transponder, Communication, Navigation and Surveillance (CNS) Systems for AIS Base Station (BS) and software, the S-AIS Network, enhancements of surveillance and security, improvement of counter piracy and suspicious movement of ships, better facilitated fisheries and environmental monitoring, more Reliable Search and Rescue (SAR) operations and Nano satellite AIS (Nano S-AIS) are discussed. 25. INTRODUCTION The Global Maritime Distress and Safety System (GMDSS) radio and satellite integrated networks are already developed and implemented for ships safety, distress alert and SAR communications. Namely, this system is not enough effective to provide a real tracking and detecting system of ships for every day navigation aids. The GMDSS radio and satellite networks need an additional integration with new CNS systems as a proposal that has to be developed providing seafarers with global communications and tracking networks introduced in this research. At this point, the GMDSS has to integrate CNS systems that use radio and satellite technologies for automated distress alerting, rapid tracking and detecting of ships in navigation and distress. Thus, this important integration has also to prevent all emergency situation during navigation employing more sophisticated, modern and reliable technique for improving collision avoidance and enhanced safety and security. On the basis of these daily requirements and necessity for modern maritime radio and satellite tracking and detecting systems onboard ships are already developed R-AIS and S- AIS working at VHF frequency band, which can be integrated with current and new CNS networks and equipment onboard ships, vehicles and aircraft. The R-AIS network and equipment are automatic tracking system used onboard ships and by Vessel Traffic Services (VTS) network for identifying and locating vessels by electronically exchanging data with other nearby ships, AIS BS for coastal waters, and via LEO satellites globally. The AIS network and equipment are providing information that supplements marine radar, and in such a way continues to be the primary method of collision avoidance for water transport. Because of usual problems during extremely bad weather conditions at sea sometimes VHF-band is so limited or interrupted by reduced propagation effects and interference characteristics caused by rainfall, very deep clouds and thunderstorms too. Therefore, the VHF-band AIS, whether radio or satellite, affected by these weather factors will be not able to provide reliable service for tracking and detecting of ships even via additional satellite VHF-band. For that reason will be necessary to deploy GEO or LEO satellite constellations via L or S-band. Information provided by AIS equipment, such as unique identification, position in real time, course and speed, can be displayed on a screen or an Electronic Chart Display and Information System (ECDIS). The AIS network is intended to assist watchstanding officers onboard ships and allow maritime authorities in each country to track and monitor ships movements in costal navigation. The AIS equipment integrates a standardized VHF transceiver with a positioning system such as an GPS, GLONASS or LORAN-C receiver, and with other electronic navigation sensors, such as a gyrocompass or rate of turn indicator. Ocean vessels fitted with AIS transponders and transceivers can be tracked by AIS BS located along coast lines or when are out of radio VHF ranges of terrestrial networks, through a growing number of satellites that are fitted with special AIS receivers. In fact, the S-AIS network needs ships to be equipped with other types of devices than R-AIS network and to use special assigned frequencies different from R- AIS network. However, the integration has to be realized in the Control Centre, which main task will be to collect position data received via both R-AIS and S-AIS for the same ships and distribute to all users. The VHF Radio Automatic Identification System (R-AIS), also know as a Radio VHF Data Link (R https://www.w3.org/1998/Math/MathML"> V D L ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is a most attractive system at present for tracking and detecting of ships for short range service in coastal navigation. Thus, more adequate designation for AIS will be Radio AIS (R-AIS), because recently is developed new Satellite AIS (SAIS) with similar service for ships and aircraft. The new Regulation 19 of the SOLAS Chapter V provides requirements for shipborne navigational equipment and sets out this equipment to be carried onboard according to ship type. In 2000 , International Maritime Organization (IMO) team adopted a new requirement, as part of a revised new Chapter V that all ships have to carry VHF AIS transponders capable of providing necessary information about the all ship to other ships and to coastal authorities automatically. The R-AIS is a new maritime surveillance system using the VHF-band to exchange all information between ships and shore Base Stations, including positions, identification, course and speed, which network is shown in Figure 1. It mainly aims is to provide collision avoidance between ships. The link budgets allow receiving transmitted R-AIS signals from space, and consequently a global maritime surveillance can be considered. However, later arise some challenges, especially regarding message collisions due to the use of a Self Organized Time Division Multiple Access (SOTDMA) protocol (not designed for satellite detecting). Thus, advanced signal processing for separation of received signals is needed. According to the IMO regulations provided by 31 December 2004 each oceangoing vessel has to install AIS transponder equipment onboard ships, which automatically broadcast regularly to the coast station ships name, call sign and navigation data. This data is programmed soon after the equipment is installed onboard and after that all this information will be transmitted regularly. The signals are received by R-AIS transponders fitted on other ships or on land based network, such as VMS systems. The received information can be displayed on a screen or a chart plotter, showing the other vessel's positions in much the same manner as a radar display. Ships fitted with R-AIS onboard equipment shall maintain AIS in operation at all times, except where international agreements or rules provide for the protection of navigational information. The R-AIS standard comprises several substandard called as "types" that specify individual for each product type. The specification for each product's type provides a detailed technical specification, which ensures the overall integrity of the global R-AIS system, within which the entire product types which must operate. Namely, there are two types of R-AIS Transceivers (for transmit and receive) "Class A " and "Class B ". The IMO regulation requires that AIS shall provide information by transmitter including the ship's identity (ID), navigational status and other safety-related information automatically to the appropriately equipped shore stations, other ships and aircraft, than to receive automatically such information from similarly fitted monitor, track ships and exchange data with shore SB facilities. At its 79th session in December 2004, IMO's Maritime Safety Committee (MSC) agreed that, in relation to the issue of freely available AISgenerated ship data on the worldwide Web. The publication on the worldwide Web or elsewhere of all AIS data transmitted by ships could be detrimental to the safety and security of ships and port facilities. It also was undermining the efforts of the IMO expertise and its Member States to enhance the safety of navigation and security in the international maritime transport sector. In addition, the Committee condemned those who irresponsibly publish AIS data transmitted by ships on the worldwide Web, or elsewhere, particularly if they offer services to the shipping and port industries https://www.w3.org/1998/Math/MathML"> [ 1,2 , 3 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . of Brochure: by CNS Systems [4] 25.1. CNS Systems R-AIS Class A Station The VDL 6000 Class A ship R-AIS transponder station of the Swedish Company CNS Systems provides IMO SOLAS compliance and also Bundesamt für Seeschiffahrt und Hydrographie (BSH) certification for installation onboard all oceangoing vessels, illustrated in Figure 2 (A). The screen presentation of this transponder is indicating the call signs of other ships and enables a user and other ships to make direct contact by text or voice communication. Another model of CNS Systems is VDL 6000 Secure Class A shipborne R-AIS transponder that operates in Standard, Silent and Secure Mode, shown in Figure 2 (B). This R-AIS is also serving for naval operation can be configured in "receive only" mode or both "receive and transmit" mode for positive identification and positioning of all ships in the vicinity. The R-AIS units secure system is designed on existing technology and supports a user to receive, schedule and transmit encrypted messages to other users. This service can include transmission of secure text messaging and to receive encrypted range and bearing. The secure R-AIS can also support simulated targets for naval operations Both R-AIS transmitters generate output power (adjustable) 1 and https://www.w3.org/1998/Math/MathML"> 12.5   W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 50 Ohm load. The unit bandwidth is https://www.w3.org/1998/Math/MathML"> 25 k H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> employing TDMA (AIS) protocol with baud rate https://www.w3.org/1998/Math/MathML"> 9600   b / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (AIS) https://www.w3.org/1998/Math/MathML"> / 1200   b / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Digital Selective Call (DSC) and GMSK (AIS)/FSK (DSC) modulation. Both transceivers are using frequency bands from 156.025 to https://www.w3.org/1998/Math/MathML"> 162.025 M H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with default channels https://www.w3.org/1998/Math/MathML"> 87   B ( 161.975 M H z ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 88   B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> ( 162.025 M H z ) , 70 ( 156.525 M H z ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Both AIS units of Secure Class A system have 3 ( 2 AIS TDMA, 1 DSC) number of receivers and Minimum Keyboard and Display (MKD) unit. The R-AIS Class A transponder is easy to install onboard any seagoing ship by connecting it to an GPS and VHF antenna or to the own antenna, illustrated in Figure https://www.w3.org/1998/Math/MathML"> 2 ( C ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and is complete after immediate connecting it to the onboard sensors. To maximize the benefit of the investment, the R- AIS Class A transponder is delivered with an interface to the electronic chart system and/or ARPA radar. Moreover, the system is designed to support long-range reporting via satellite, which will be introduced in the next context below. To maximize the benefit of the functionalities, both R-AIS Class A transponders are delivered with an interface to the chart system and/or ARPA radar. The data link communication covers identity, position, destination and other required static, data voyage-related and dynamic data, which gives all vessels in an area increased situational awareness and improves safety at sea for the individual ship. Positive identification and positioning of all ships in the vicinity reduces the unnecessary "ship on my port bow" calls. Less information overload greatly enhances safety at sea. The SOTDMA technology is used in the R-AIS transponder, which transmits and receives useful information on all vessels within VHF coverage. This information includes position, identity (ID), course over ground, heading and rate of turn as well as navigational status and the destination of the ship. Thus, the information received from, and provided to, the ships is easily plotted on any ARPA radar or electronic chart system. This gives the officer of the watch a situational awareness that could never be achieved prior to AIS. In such a way, information on draught, type of cargo and destination could also be used to make decisions related to the ship maneuvering, so at this point is accomplished the maximum awareness. Targeted at large commercial oceangoing ships, SOTDMA mode requires an AIS transceiver to maintain a constantly updated slot map in its memory such that it has prior knowledge of slots, which are available for it to transmit. Moreover, the SOTDMA transceivers will then pre-announce their transmission and effectively reserving theirs transmit slot. Thus, this transmission is achieved through two receivers in continuous operation. Class A unit has an integrated display, transmit at https://www.w3.org/1998/Math/MathML"> 12   W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , interface capability with multiple ship systems, and offer a sophisticated selection of features and functions. In default transmit rate it sends information every few seconds providing tracking control of vessel. Described system is transmitting all necessary tracking information with help of the VHF transmitter to other nearby ships and to coastal base station (BS) https://www.w3.org/1998/Math/MathML"> [ 2,4 , 5 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . ICOM [6] 25.2. Icom MA500TR Class BAIS Transponder The MA-500TR is a Class B R-AIS transponder for Non-SOLAS vessels such as pleasure craft, workboat, fishing and small vessels. Transmitter power of this unit is https://www.w3.org/1998/Math/MathML"> 2   W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and not required to have an integrated display. Class B R-AIS can be connected to most display systems, which the received messages will be displayed in, lists or overlaid on charts. In Figure 3 is presented interface of Icom MA-500TR Class B AIS transponder with antenna, which can be installed usually onboard small vessels, which is not complaining to the necessary requirements of IMO regulations https://www.w3.org/1998/Math/MathML"> [ 2,6 , 7 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 26. BASIC TECHNICAL DETAILS OF AIS TRANSPONDER Vessel with mounted onboard both R-AIS type Class A and B transceivers employ Carrier Sense TDMA (SCTDMA) or Self Organizing TDMA (SOTDMA), which AIS network is illustrated in Figure 4 The system is automatically sending and receiving data via the standard vessel's radio units. In such a way, they use two VHF channels simultaneously, such as https://www.w3.org/1998/Math/MathML"> 87   B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 161.975 M H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and channel https://www.w3.org/1998/Math/MathML"> 88   B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at 162.025 https://www.w3.org/1998/Math/MathML"> M H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Therefore, to order a lot of vessels sending out their data, the AIS transmission protocol works with 2250 slots per minute which can be used by different senders to transmit their information. Figure 4. Maritime SOTDMA AIS Transmissions - Courtesy of Brochure: by AMSA [8] Figure 5. Maritime AIS Base Stations - Courtesy of Brochure: by CNS Systems [4] The SOTDMA mode is used to autonomously divide the available timeslots between different senders. Due to the limited range of VHF and the different transmission intervals of senders the number of slots is sufficient and collisions hardly occur. An AIS system sends out via Base Station different types of information in varying time intervals. In total, AIS is able to communicate 27 different message types. Message https://www.w3.org/1998/Math/MathML"> # 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> e.g. is the position of the vessel. In such a way, transmitted information by this unit is: Maritime Mobile Service Identity (MMSI) code, Vessel name, Call sign, Type of ship, GPS antenna position, Ship's position, SOG (Speed Over Ground), COG (Course Over Ground), UTC date and time, GPS antenna type, PA (Position Accuracy) and Simple operation. Not all messages are regularly used. The AIS Plotter display looks like a usual marine radar display. North-up, course-up and range zoom from 0.125 to 24 NM (miles) are supported. The Target list display shows all detected AIS equipped vessels and targets. The Danger list display shows a list of vessels that are within https://www.w3.org/1998/Math/MathML"> 6 N M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of Closest Point of Approach (CPA) and 60 minutes of Time to CPA (TCPA) from own vessel. Therefore, the Danger list can be sorted by CPA or TCPA order. In addition to these display types, the Detail screen shows various information about the selected R-AIS targets, such as CPA and TCPA for collision-risk management. When a vessel comes into the CPA and TCPA range, the unit icon blinks on the Plotter display and emits a beep sound. When connected to external audio equipment installed on the deck tower, the collision alarm function will alert operator even when is away from the AIS transponder https://www.w3.org/1998/Math/MathML"> [ 2,4 , 8 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 27. CNS SYSTEMS AIS BASE STATION (BS) Maritime R-AIS Shore Stations are used for surveillance and management of vessel traffic along coastlines, on inland waterways and in ports. These stations are providing all the features required for surveillance and management of vessel traffic at R AIS VTS. They are easily configured to the specific needs of necessary service and solutions, from a basic unit to a fully redundant system with an embedded controller providing extensive processing and logging functionality. These R-AIS base stations fulfill the requirements of international AIS standards, provide service for national maritime authority implementing an R-AIS network and are also suitable for stand-alone operation at an VTS or seaport. The Swedish Company CNS Systems has two designs of Maritime R-AIS Base Stations: VDL https://www.w3.org/1998/Math/MathML"> 6000 / F A S S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , illustrated in Figure 5 (Left) and VDL 6000/ FASS Advanced, shown in Figure 5 (Right). All AIS ships stations automatically broadcast information on dedicated VHF maritime channels. The AIS broadcasting system consists of static (geostationary), dynamic (non-geostationary) and navigation information, shown in Figure 6. All this information is originating from ships sensors connected to the R-AIS transponder. R-AIS Station sends position reports every 2 seconds to 3 minutes, depending on type of R-AIS transponder, speed and turn rate. Thus, the received R-AIS information at Base Station can be shown on a VTS Operator's screen or an ECDIS display. 27.1. CNS Systems AIS Base Station VDL 6000/FASS The VDL 6000/ FASS is configured as an AIS BS terminal illustrated in Figure 5 (Left), which includes two VDL 6000/FASS (Fixed AIS Station System), one base station transponder and one controller in each FASS unit and one Power and Antenna Distribution (PAD) unit. The AIS network with AIS internship reports and reports between ships and AIS BS are presented in Figure 7 (A). In Figure 7 (B) is illustrated the Multifunction Displays for Marine's Integrated Platform Management System (IPMS) for AIS VTS infrastructure, which also can be used as Integrated Bridge System (IBS) display for installation onboard ships https://www.w3.org/1998/Math/MathML"> [ 2,3 , 9 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This AIS BS configuration is a cross redundant AIS shore terminal with high reliability and full redundancy on all electronic components. On the other hand, this unit exceeds all the requirements of international AIS BS standards and provides all the features required for surveillance, detecting and management of vessel traffic. The AIS BS will automatically switch over to the stand-by FASS unit if the active one goes down (hot stand-by). It can also use the controller and BS terminal crosswise in case of dual failures of hardware. This solution gives extremely high Mean Time Between Failure (MTBF) and availability and very low mean time to repair, reducing the need for unscheduled maintenance. The calculated MTBF of the AIS BS is more than 3 million hours, provided faulty units are replaced within 72 hours. The PAD unit contains an VHF antenna switch which can be used when only one VHF antenna is required. If dual VHF antennas are used at the installation site, the VHF switch can be bypassed by connecting directly to the two VDL https://www.w3.org/1998/Math/MathML"> 6000 / F A S S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> units VHF antenna ports. The AIS BS station provides many additional remote functionalities, including configuration, software updates, virtual targets and more. Other functions are local storage of AIS messages, local target filtering and Simple Network Management Protocol (SNMP). Power management is also integrated in the PAD unit. This feature makes it possible for the user to remotely switch the FASS units power on and off, what is giving the operator full control. Therefore, the AIS BS is designed for operation in secure mode by handling encrypted AIS data. The secure mode enables secure communication between ship-to-shore station and the control centre. Thus, by adding the secure modules to the network software, encryption and decryption can be managed between the users in a secure AIS network. The AIS BS transponder can be supplied with a third AIS channel as well as increased receiver sensitivity. The AIS BS is employing Power IP relay IF TCP/IP and RJ45 Ethernet with transmitter and receiver tuning range at https://www.w3.org/1998/Math/MathML"> 156.025 - 162.025 M H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and with channel spacing of 12.5 and https://www.w3.org/1998/Math/MathML"> 25 K H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Modulation scheme is https://www.w3.org/1998/Math/MathML"> 25 K H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> GMSK (AIS TDMA ), https://www.w3.org/1998/Math/MathML"> 2.5 K H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> GFSK (AIS TDMA) and https://www.w3.org/1998/Math/MathML"> 25 K H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> FSK (DSC). The AIS BS station is containing GNSS Receiver as well with GPS L1, 16 parallel channels and DGNSS support. Figure 7. Maritime AIS Network and Display - Courtesy ofManual: by Ilcev [2] Manual: by Ilcev [2] 4.2 CNS Systems ADS Base Station VDL 6000/FASS Advanced The Advanced configuration has one transponder and embedded controller hardware running unique software from CNS Systems, shown in Figure 5 (Right). This BS terminal can be installed as a single equipment providing AIS message logging, remote configuration and software update, virtual and synthetic targets, SNMP, local target filtering, remote power on/off and more. Two shore BS terminals can be locally connected to form a fully redundant installation, where their hot-standby operation including mutual cross-wise redundancy transponder and controller between the units provides very high availability. This AIS shore BS is delivered with the Monitor and Control Tool (MCT) and the Power Supply Management Tool (PSMT). Therefore, the MCT is a graphical interface that provides monitoring and control capabilities such as; change of status of the base station and its subunits, change of operational mode, enabling and disabling of services, configuration of the base station and its subunits, display of number of transmitted and received messages as well as software update. The PSMT allows a user to control the power supply to the base station and its subsystems. It can be factory configured for the following base station types: AIS BS, Limited AIS BS, Repeater BS and Aids to Navigation (AtoN) transmitting only BS. With the Repeater station this BS is the perfect choice when implementing an AIS network where extended coverage at remote locations is required. This AIS BS is equipped with dual VHF antennas provides a number of functions, including filtering of AIS targets by selection of MSG type and/or filtering of a defined area. Otherwise, the dual antenna configuration allows the Repeater station to receive and transmit on directional antennas. This greatly improves coverage and distance in an AIS network, so for example in Figure 8 is shown advantage of AIS vs Radar. Both ships do not have radar contact due to the difficult terrain, but can see each other by AIS. However, sometimes in more mountainous shore line there is not LOS between ships or between ships and base station, so can be used Satellite AIS instead. In order to simplify the functionality of AIS network it is necessary to construct the network model basing on a LAN. The system can use two ways to construct such a network. The first way is based on computing node, which communicate and exchange data or message each other via computer. The second is based on switching node, which contains data switches and equipment for controlling, formatting, transmitting, routing and receiving data packets https://www.w3.org/1998/Math/MathML"> [ 2,4 , 8 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 28. CNS SYSTEMS AIS BS AND SHIP STATION SOFTWARE The CNS Systems company is also supplier of important software for use by the AIS base and ship stations. There are two CNS Systems software for supporting onboard AIS stations, such as Aldebaran II and Sentinel. However, there are four software solutions used at Base stations, such as Horizon, DataStore, DataSwitch and Maestro. 1 Aldebaran II - This is Electronic Charting System (ECS) software for use onboard ships. In fact, it is designed with advanced navigation and communication features and is used by AIS operators worldwide. However, the ECS solutions improve efficiency and safety in today's fast paced computer-aided navigation and situational awareness environments. It offers complete AIS units integration with the ability to display static, dynamic and voyage related information in real time on a multitude of electronic chart formats. 2 Sentinel - This is AIS surveillance and secure information system built on proven AIS display technology for use by operators in the need for secure communication. It offers AIS standard and private communications capabilities to deliver a common operating picture to all users. It permits the simultaneous covert tracking of standard AIS participants, allowing operators to monitor the network without being detected. 3 Horizon - This is shore-based (BS) vessel monitoring solution designed for vessel traffic and monitoring centres. Horizon is ideal for vessel traffic monitoring in national waters, and has been proven to increase safety, security and efficiency. It provides a complete AIS interface that includes the ability to view and track all vessels, display specific vessel information and send and receive safety related and text messages. Its interface and display of AIS related data offers a substantial leap forward in the ability to communicate and interact with vessels. Since Horizon is fully configurable, operators can adjust the display of information panels, customize color patterns for AIS targets and set entry and exit alarms. 4 DataStore - This is a real-time data logging and playback software solution for National Marine Electronics Association (NMEA) and NMEAformatted data, specifically AIS data. The "backend" of the solution is a service that interfaces with a database, and the "front-end" interfaces with an application that allows a user to control logging and playback of data. DataStore can be configured to store all data or a user defined subset of data. Data stored in the AIS database can be queried and played back in the ECS system or an external application. 5 DataSwitch - This is a special data routing and management software application that provides a reliable flow of data to environment. DataSwitch supports the functionality defined in International Association of Lighthouse Authorities (IALA) Recommendation A-124, LSS Layer and Part IV. It is ideal for the collection, filtering, logging and sharing of AIS data over networks. For shore BS networks, it enables the flow of information from one or more AIS base stations and/or receivers to a Vessel Traffic Service (VTS) centre. Similarly, a VTS center can send vital data to a regional headquarters, and then on to a national entity via another DataSwitch. For a vessel-based network, DataSwitch can send information from attached NMEA devices (sensors) to a number of stations on the vessel. The distribution of both standard and proprietary data messages from one central location to shared locations makes DataSwitch essential in many diverse environments. 6 Maestro - This software provides top layer control for the AIS network, supporting the functionality defined in IALA Recommendation A-124, Functionality of the AIS Service Management (ASM) and Part V. It is a graphical display interface and configuration utility for the AIS network. 7 Maestro monitors all AIS network components including status and failure of all components, warnings about failover and backup systems, user account status, and all other relevant events. From the single interface accessed via a web browser, Maestro users can monitor, maintain, and manage all elements of the AIS network. Maestro is an independent process that runs without affecting the other AIS services https://www.w3.org/1998/Math/MathML"> [ 2,3 , 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , 5 ]. 29. SATELLITE AUTOMATIC IDENTIFICATION The recently developed VHF Radio - Automatic Identification System (R-AIS) network, being an RF-based communications system was never designed for reception of signals from space, however Satellite AIS (S-AIS) greatly extends the range of the original system and creates new application possibilities for competent maritime and aeronautical authorities. Visibility scope is significantly enhanced using S-AIS and in such a way this solution provides global coverage and creates increased CNS situational awareness well beyond the 50 NM range from shore. Similar to the VHF R-AIS ship terminal, the VHF S-AIS unit is easy to install onboard any seagoing ship by connecting it to GPS receiver, gyro and the Pilot Plug interface. Therefore, most terrestrial-based R-AIS networks provide only limited shore-based coverage via VHFband to track and monitor vessels, and thus are not able to provide global, open ocean coverage. The Orbcomm and other LEO satellite network including Nano (CubeSat) satellites overcomes many of these challenges with unique S-AIS data service that can monitor a vessel's location and daily status well beyond coastal waters and ports to assist in navigation and improve maritime safety and security. More importantly, the Orbcomm and other LEO networks can do this cost-effectively and in nearreal-time transmissions. The Orbcomm system was the first commercial satellite network providing SAIS data services. At this point, Orbcomm has licensed S-AIS service to over 100 different customers in a variety of government and commercial organizations. The Orbcomm S-AIS network and service offers valuable data for applications that maximize global maritime safety and security, enabling the maritime industry to know where nearly every vessel is located, where it is going and when it will arrive at its destination. Orbcomm has already provided access to tracking and detecting information from well over 120,000 unique vessels daily by leveraging proven expertise and existing worldwide ground infrastructure. In addition, by partnering with some of the most trusted maritime information providers in the world, such as Inmarsat, the Orbcomm system may offer the most complete situational picture of global vessel activity. In May 2004, the US Coast Guard awarded Orbcomm a contract to develop and supply new SAIS service and network to meet their national security requirements. By utilizing Orbcomm S-AIS service, security and intelligence departments around the world can know where nearly every vessel is located, where it is going and when it will get there. In fact, these valuable data can be used to quickly react to anomalies at sea such as piracy and suspicious movements, contraband and route deviation, SAR, fishery and environmental monitoring and other unusual behavior. Except Orbcomm satellite system, to establish SAIS system can be used existing GEO and NonGEO satellite networks on L or UHF-band, shown in Figure 9. In fact, it will be necessary to provide adequate satellite constellation, CES terminals, mission operation, data processing centre, operation centers and customer delivery of S-AIS service. Onboard ships S-AIS equipment can send two types of messages, the first type is inter ship communication of ship-to-ship AIS reports, and second type is direct transmission of AIS messages via SES, Internet or terrestrial communication line to the AIS Data Centre. The shore AIS Data centre provides processing of all receiving data and is forwarding S AIS messages instantly to the customer facilities via Internet. 30. 6.1 Enhancements of Surveillance and Security The proposed S-AIS system and network will improve monitoring, surveillance and security in navigation of ships at deep sea and coastal waters where R-AIS has not coverage. Namely, the new SAIS network maximizes maritime safety and security, which service is thought to be the most significant development in maritime navigation safety and security since the introduction of radar. This system is a shipboard broadcast system that also transmits a vessel's identification, position and other critical information to provide the most complete and timely situational picture of vessel activity worldwide. Thus, the benefits of S-AIS in helping maritime authorities and shippers globally are to enhance maritime domain awareness and surveillance through detecting and identification of all ship's sailing route deviation and suspicious movements. In fact, by utilizing S-AIS service, security and intelligence departments around the world can find out where nearly every vessel is located, where it is going and when it will get there. These agencies can use this valuable data to quickly react to any anomalies at sea, such as suspicious movements, route deviation and other unusual behavior of pirate and contraband boats. The use of data fusion by merging S-AIS data with sensors such as electro optical imaging and Satellite Synthetic Aperture Radar (SSAR) enables the rapid and reliable identification of S-AISemitting vessels and highlights non-S-AIS-emitting vessels. This data has proven to be beneficial for government authorities responsible for security, fisheries, exclusive economic zones and environmental monitoring in improving security and safety efforts. From more efficient management of port traffic, to support of national surveillance initiatives, to collision avoidance and other benefits, S-AIS service is helping to keep global waterways more safe and secure. Therefore, received data from these agencies can be used just for commercial purposes, however for collision avoidance new S-AIS system cannot work without establishment of special ground tracking centres, which have to provide positions of all adjacent ships to the certain ship requesting these data. In such a way, ships captain getting this electronically information with positions of all surrounded ships can easily and safe navigate even in the extremely bad weather conditions. 30.1. Improvement of Counter Piracy and Suspicious Piracy in high-risk areas has become a major threat to regional trade and maritime security in recent years. As the frequency and aggressiveness of pirate attacks has increased, the need for S-AIS service in mitigating the risk of piracy is more important than ever before. As stated before, it can be used to locate approach of pirate boats, suspicious movements and to identify ships of interest, such as terrorist attacks, contraband and so on. Namely, the S-AIS can help alert vessels to a potential threat so fleet operators can avoid, deter or delay piracy attacks and greatly reduce risks to the vessel and crew. This system reduces the escalating threat and dangerous impacts of piracy and improves vessel safety and security is more important than ever before. The S-AIS system and network enhance detecting of ships movement at sea, identifies vessels of interest and filter out "friendly" ships, especially in high-danger areas. If there is a data anomaly with regard to ID, location or speed, maritime authorities can use S-AIS data to determine the variance in reported versus actual status and take immediate action. This system can also be used to reduce the need for routine patrol missions at sea and help dispatch the appropriate authorities quickly when security incidents occur and in such a way significantly to improve the efficiency of all maritime operations. In addition, by providing proven and reliable real global coverage, S-AIS delivers uninterrupted satellite data service even when the traditional shipboard communications systems and alarm transponders may have been compromised. Post-piracy tracking and reporting via S-AIS can be also used to identify typical ships traffic patterns and activities in high-risk sea areas, which can significantly help local and national security organizations proactively counter piracy hijackings, kidnappings and extortion. 31. 6.3 Better Facilitated Fisheries and Environmental The new S-AIS network is providing access to timely, accurate vessel data as an instrumental in supporting fisheries management, environmental protection, all pollution preventions and modern transport operational compliance programs in global waterways. From the prevention of marine daily pollution incidents to the enforcement of fishery regulations to vessels traffic management, S-AIS service provides the maritime industry with complete and reliable visibility over ships activity worldwide. The S-AIS information service is also cost-effective and reliable resource for shippers, ship operators, seaport authorities and government agencies to help prevent environmental disasters, enforce fishery regulations and ensure the safety of mariners. The S-AIS service can be used to manage fishing activities, quotas and harvesting limits by alerting authorities of vessels entering closed or protected environmental zones. Namely, the best result is a reduction in illegal fishing and the preservation of depleting ocean resources. Thus, this system is also able to track historical traffic patterns and identify violators within these protected areas. Environmental organizations leverage S-AIS data to determine if a vessel has been in an area where oil, hazardous waste or ships ballast has been deliberately discharged or leaked to determine who is responsible for polluting the water. This service can also provide valuable data to all maritime authorities regarding the activity of vessels around and within such environmental or navigation hazards at sea, enhancing maritime safety and enabling those authorities to take immediate necessary actions. Besides, in support of fisheries control and environmental protection, relevant maritime authorities around the world have to detect and identify illegal, unreported and unregulated fishing activities. As stated earlier, the S-AIS system can integrate its satellite data with sensors such as surveillance radar and deliver comprehensive monitoring reports to authorities responsible for fishery ships, exclusive economic zones and environmental monitoring. 32. 6.4 More Reliable Search and Rescue Operations In an emergency incident when loss of life or the watercraft is imminent or threatened by grave danger, timing is becoming everything. The faster that information can be communicated to the first responders such as coast guards, maritime or other competent authorities, the faster that help can be sent on the way. The most effective solution for improving ship safety including the precision and efficiency of international SAR operations is Cospas-Sarsat, LRIT and after that global S-AIS data service. This service is a new shipboard broadcast system that transmits a vessel's identification, position, speed and detecting other critical data to provide a complete and reliable situational picture of near-real-time vessel activity worldwide. For vessels in distress alert and during SAR operations the S-AIS service can identify exactly where a vessel is located anywhere in the world even if it continues to drift from the distress location. Access to accurate, reliable and timely data about the position and status of a vessel and its crew can greatly improve response time by focusing SAR resources to a specific area and enhancing overall rescue coordination. Most importantly, S-AIS data can help minimize damage to and loss of the vessel, potentially saving lives. This valuable positioning service is also helpful in tracking the status of the rescue team and reducing risk to the rescuers, especially in treacherous heavy weather or water conditions. Orbcomm and other Non-GEO satellite operators today are providing efforts to develop VHF or UHF S-AIS network for all mobile applications and especially for maritime commercial and SAR on scene operations. In such a way, Orbcomm Little LEO satellite operator is the first mobile commercial satellite network who is developing and implementing S-AIS Data Service. In 2008 , Orbcomm team launched the first LEO satellites specially equipped with the capability to collect AIS data and has plans to include these capabilities on all future satellites for ongoing support of global safety and security initiatives. Orbcomm mobile satellite operator recently has successfully launched six satellites with S-AIS equipped payloads. Orbcomm's next launches started in 2011, which AIS satellite is shown in Figure 10 (A). Following the development of Orbcomm system is designed sample of the M3MSat Maritime AIS CubeSat (Nano) satellite for the Canadian government, shown in Figure 10 (B), which was launched in 2012 . The future S-AIS network is ideal for global satellite ships tracking and surveillance useful by maritime and govermment administration, but as stated earlier, is not dedicated for a real collision avoidance of ships. Thus, to enhance R-AIS and SAIS service has to be provided the similar system as proposed Global Ship Tracking (GST). The GST system is augmented LRIT network, which except ship tracking provides tracking of captured ships by pirates and enhanced collision avoidance. Its Tracking Control Stations (TCS) is collecting positioning data of all ships in any sea area, indicating them on the radar like display and distributing them on any ship request sailing in certain sea area. The disadvantages of Nano and LEO satellites is that they need several dozen of spacecraft to build complete coverage, could interfere with satellite operations and space missions, short equipment lifespan, enhanced atmospheric drag, increasing danger from space debris from many non-working satellites, handover problems and short visibility over horizon. To get more reliable S-AIS network has to be employed GEO satellites, as the best solutions for S-AIS. In Figure 11 is shown by Cain & Meger one of the S-AIS operational results to globally track the ships, which is useful for commercial purposes https://www.w3.org/1998/Math/MathML"> [ 2,3 , 5,10 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 33. NANO SATELLITE AIS (NANO S-AIS) An AIS receiver using satellite will be able to extend the VHF-band range of R-AIS systems considerably and make it easier to monitor ship traffic and fishing in the High North areas. Figure 11. OperationPaper: by Cain [10] Courtesy of Presentation: by Ilcev [5] Recently many countries developed cost effective small satellites in LEO constellations. They are categorized by their weight, such as Pico less than 1 https://www.w3.org/1998/Math/MathML"> - 5 K g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Nano less than https://www.w3.org/1998/Math/MathML"> 10 - 50 K g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and Micro satellites less than https://www.w3.org/1998/Math/MathML"> 100 - 200 K g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which measure less than 0.5 meter The ITU regulations are not geared for these smaller satellites, but recently were proposed their frequencies in the range of https://www.w3.org/1998/Math/MathML"> 137 M H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 2,450 M H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . No matter what smaller satellites have limited lifetime, short lifetime of batteries and orbit control capabilities, they can be used as cost-effective missions for tracking, detecting and remote sensing. Based on different studies and examples in which Nano satellites were exposed to the different levels of radiation, some CubeSat electronics Secure Digital (SD) cards especially are susceptible to any errors from radiation. In addition, space radiation can be mitigated to some degree through shielding and material choice or via special software by clever use of watchdog timers and special "self-aware" coding as well, where self-verification is consistently monitored. With regards to the smallest satellite life time, CubeSat at orbit lower than https://www.w3.org/1998/Math/MathML"> 300 K m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> will be 0-100 days, these from 300 to https://www.w3.org/1998/Math/MathML"> 400 K m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are a danger of collision with the International Space Station (ISS), because that the orbit of ISS is usually maintained between https://www.w3.org/1998/Math/MathML"> 335   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> perigee and https://www.w3.org/1998/Math/MathML"> 400   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> apogee. A CubeSat in this altitude band could last for 0.5 to 2 years. In contrast, the lifetimes of higher altitude satellites than https://www.w3.org/1998/Math/MathML"> 600 K m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> could be theoretically up to two decades. In Figure 12 (A) is illustrated larger coverage area using S-AIS or even AIS via High Altitude Platforms (HAP) versus using smaller coverage of conventional system of VHF R-AIS. The altitude of the LEO satellite or HAP station gives the AIS receiver a large range of coverage and both can therefore make observations over extended sea areas. The VHF AIS signals are strong enough to be received by an SCP or satellite. The new developed AISSat-1 is a Nano satellite in LEO measuring https://www.w3.org/1998/Math/MathML"> 20 × 20 × 20   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , weight is https://www.w3.org/1998/Math/MathML"> 6 K g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and is shaped like a cube (CubeSat), shown in Figure 5.24 (B). The satellite payload is designed by the Kongsberg-Seatex AS Company and the purpose of the satellite is to improve ships surveillance of maritime activities in the High North sea areas. It is believed that the low traffic density in the High North requires one receiver and antenna only to handle the expected volume of AIS messages. So, the AISSat-1 satellite is being launched in order to test these presumptions and if is successful to be used for S-AIS facilities. The AISSat-1 satellite will operate in a Polar orbit at an altitude of about https://www.w3.org/1998/Math/MathML"> 600 K m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and is proposed to be launched by the PSLV rocket of the Indian Space Research Organization (ISRO). Thus, the Norwegian Space Centre is project owner and the Norwegian Coastal Administration (FFI) will receive the data, while the Norwegian Defense Research Establishment is responsible for the technical implementation. Additional information about this project is possible to see at Web pages of Kongsberg Maritime. Courtesy of Brochures: SFL/US https://www.w3.org/1998/Math/MathML"> [ 11,12 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The Norwegian AIS transponder is also placed in a Canadian Nano satellite, built by the University of Toronto (UOT), which life span is estimated to three years. The Institute for Aerospace Studies/Space Flight Laboratory (UTIAS/SFL) of UOT has been developed prototype of Generic Nanosatellite Bus (GNB) to fly a verity of payloads, ranging from SAIS tracking solutions to precision formation flying. With the successful launch of the CanX-2 mission, technological validation is paving the way for the next generation of GNB derived CanX missions. The COM DEV Ltd launched Nanosatellite Tracking of Ships (NTS) spacecraft at the end of April 2008 following an unprecedented 8-month kick-off to launch cycle, which components are shown in Figure 13 (Left). In Figure 13 (Right) is shown CubeSat SumbandilaSat, microsatellite designed by Stellenbosch University (SU) in Cape Town, South Africa. This satellite launched 17 September 2009 by Russian Soyuz-2 launch vehicle from the Baikonur Cosmodrome will serve for Earth observation with design lifetime of 3 years at an orbit altitude of https://www.w3.org/1998/Math/MathML"> 500 K m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (subject to average sun activity) https://www.w3.org/1998/Math/MathML"> [ 2,5 , 11,12 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 34. CONCLUSION In this article were discussed basic of R-AIS with major class of AIS transponders for installation onboard ships and BS for shore installations. In addition is introduced new S-AIS via Orbcomm Little LEO satellite constellation and via proposed small LEO satellites. Here the question is aroused, namely, whether Little LEO satellites, such as Orbcomm or small satellites can provide full, cost effective coverage and reliable S-AIS service? The total cost of new generation Orbcomm network with 36 satellites in constellation is about 234 million US$and will be able to provide global coverages except both poles. However, the total cost of the AISSat-1 Nano satellite is approximately 30 million NOK (Norwegian Crown) or about 4 million US$ each. The another question is, how many Nano satellites will be necessary for total coverage of Earth including polar areas, when in the same time Big LEO Globalstar has 40 satellites in constellation and Iridium with 66 satellites in constellation is providing full coverage of Earth including both poles. Inmarsat GEO satellite operator is only professional network providing near global coverage up to 800 North and South. At present ships are not up to 800 North and South. At present ships are not these routes, so at present only Iridium is able to provide polar coverage. However, for additional coverage over North Pole Inmarsat needs Hybrid Satellite Orbits (HSO), such as GEO and Medium Earth Orbit (MEO) or GEO with High Elliptical Orbit (HEO) Russian Molniya spacecraft. However, at present Inmarsat is setting advanced new Inmarsat-5 GEO satellite constellation, which will provide broadcasting and broadband satellite office at sea. Perhaps cost of about 50 million US$to launch one Inmarsat- 5 spacecraft is not extremely high for significant professional maritime communications. 35. REFERENCES [1] IMO, "AIS Transponders", London, 2015 [https://www.imo.org/OurWork/Safety/Navigation/Pages/AIS.aspx], [2] Ilcev D.S., "Global Mobile Communications, Navigation and Surveillance (CNS)", Manual, DUT, Durban 2014 [www.dut.ac.za/space_science]. [3] Skoryk I., "Radio and Satellite Tracking and Detecting Systems for Maritime Applications", Doctoral Thesis", Durban University of Technology (DUT), Durban, 2014. [4] CNS Systems, "VDL 6000 AIS Class-A & Secure Class-A Transponders", Linkoping, Sweden, 2014 [https://www.cns.se/] [5] Ilcev D. S., "Global Ship Tracking, Automatic Identification System and Determination", Research Group in Space Science, DUT, Presentation, 2011 [www.dut.ac.za/space_science]. [6] Icom, "Class-B AIS Transponder", Osaka, Japan, 2014 [https://www.icom.co.jp/world/]. [7] Orbcomm, "Global Visibility Beyond Coastal Regions", AIS, Rochelle Park, 2015 [https://www.orbcomm.comnetworks/ais] [8] AMSA, "Automatic Identification System (AIS) Class A", Australian Maritime Safety Authority, Canberra, 2015, https://www.amsa.gov.au/forms-and-publications/factsheets/aisa_fact.pdf [9] MRS, Automatic Identification System (AIS), Marine Radio Service, Klang, Malaysia, 2015 https://www.mrsmarine.com.my/index.php/products-services/ais-class-b [10] Cain J., & Others, "Nanosatellite Tracking of Ships Review of the First Year of Operations", 7th Responsive Space Conference, Los Angeles, 2009 [https://www.responsivespace.com/Papers/RS7/SESSIONS/ Session https://www.w3.org/1998/Math/MathML"> % 20 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> V/6005 Newland/6005P.pdf ] [11] SFL, & Others, "Nanosatellite Tracking Ships: CostEffective Responsive Space", Space Flight Laboratory (SFL), Toronto, 2014 [https://utias-sfl.net/wpcontent/uploads/LAC2010-S16-1-Nanosatellite-tracking-FPranajaya.pdf ]. [12] Steyn S., "Satellite Engineering Research at US", Cape Town, 2012 [https://staff.ee.sun.ac.za/whsteyn/Papers2/US_Satellite_Research.pdf]. Satellite Antenna Infrastructure Onboard Inmarsat Spacecraft for D.S. Ilcev Durban University of Technology (DUT), South Africa Abstract In this paper is introduced antenna systems onboard spacecraft for Inmarsat Aeronautical and other Mobile Satellite System (MSS), such as communications, tracking, monitoring and logistics solutions between mobile units and Gateways or Ground Earth Stations (GES) accomplished via Geostationary Earth Orbit (GEO) Satellite Constellation. Inmarsat GEO MSS is employing advanced technology and technique to deliver Voice, Data and Video (VDV) for all mobile applications around the world, excluding Polar Areas. The Inmarsat organization got sufficient funding to implement at first solutions for Maritime applications and in the next stage to develop additional service such as Land (Road and Rail) and finally for Aeronautical applications. Inmarsat team surpassed all problems and challenges getting attribute of only one global mobile satellite operator with professional attribute. With respect to improvements of Space Segment and service in particular, antenna systems onboard Inmarsat spacecraft is discussed. The characteristics of modern Spacecraft antenna and Link Performance with Monobeam and Multibeam Antenna Coverage are introduced. At this point, the possible basic types of antenna installed onboard spacecraft for MSS are presented. 36. INTRODUCTION OF INMARSAT GEO MSS The first GEO Mobile Satellite Communications (MSC) maritime system was proposed and built by the International Maritime Organization (IMO) from London in 1979 , known as the International Maritime Satellite Organization (Inmarsat). At the beginning Inmarsat was not-profit organization for providing maritime satellite communications including distress and safety solutions. In the next stages Inmarsat developed additional services for land (road and rails) and aeronautical applications. For the first decade of operations, Inmarsat leased the Space Segment form Comsat (three Marisat satellites F1, F2 and F3), from ESA (two Marecs satellites A and https://www.w3.org/1998/Math/MathML"> B 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) and from Intelsat (three Intelsat https://www.w3.org/1998/Math/MathML"> V - M C S A , B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and D). These Inmarsat satellites were initially configured in three ocean regions: AOR, IOR and POR, each with an operational satellite and one spare in-orbit. This satellite constellation is known as the first generation of the Inmarsat network. Inmarsat was not responsible for TT&C, but operations were controlled by Inmarsat Network Control Centre (NCC) in London. Then, Inmarsat operated with four 2 nd generation Inmarsat-2 birds launched in 1990/92 with a capacity equivalent to about 250 Inmarsat-A voice circuits. These satellites were built to provide coverage of four ocean regions: AOR-E, AOR-W, IOR and POR by the Space and Communications division of British Aerospace (Matra Marconi Space). The US Lockheed Martin company built the new spacecraft bus for next Inmarsat-3 generation of spacecraft, based on the GE Astro Space Series https://www.w3.org/1998/Math/MathML"> 4000,2.5 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> high and with a 3.2 radial envelope centered on a thrust cone. Thus, Matra built the communications payload, antennas, repeater and other electronic equipment. Payload and solar arrays are mounted on N and S-facing panels, while L-band Receiver (Rx) and Transmitter (Tx) reflectors, mounted on E and W panels, are fed by an array of cup-shaped elements. Furthermore, the navigation antenna is located on the Earth-facing panel. The tremendous advantage of the Inmarsat- 3 satellites is to concentrate power on particular areas of high traffic within the footprint. Each GEO satellite utilizes a maximum of seven spot beams (A) and one global beam coverage (B) shown in Figure 1 . These satellites also can re-use portions of the Lband for non-adjacent spot beams, effectively doubling the capacity of the satellite. Responding to the growing demands from the corporate mobile satellite users of high-speed Internet access and multimedia connectivities, Inmarsat built fourth generation of Inmarsat-4 satellites as a Gateway for the new mobile and personal satellite broadband network. Inmarsat has awarded European Astrium a 700 million US$ contract to build three Inmarsat I-4 satellites, which will support the new Broadband Global Area Network (BGAN). The BGAN personal and mobile applications have to deliver Internet and Intranet content and solutions, video on demand, videoconferencing, fax, E-mail, phone and LAN access onboard mobiles at speeds up to https://www.w3.org/1998/Math/MathML"> 432   K b / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> worldwide, compatible with https://www.w3.org/1998/Math/MathML"> 3 G https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cellular systems. Finally, Inmarsat has contracted the US Boeing, to build a constellation of new three multipurpose Inmarsat- 5 satellites as a part of a global wireless broadband network Inmarsat Global Xpress. The first satellite Inmarsat-5 F1 entered in commercial service on 30 June 2014 . The second and third I-5 satellites are on course to launch by the end of 2014 and will provide global coverage during 2015 . The spacecraft will provide radio spectrum on L/C and Ka-band for both communication and GNSS (navigation) facilities. The most important parts of Inmarsat spacecraft are antenna for satellite communications and navigation facilities https://www.w3.org/1998/Math/MathML"> [ 1,2 , 3,4 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Figure 1. Spacecraft Antennas Spot 37. BASIC PARTICULARS OF SPACECRAFT The spacecraft antenna radiates EM energy to the ground stations in both directions, efficiently and in desired path. Satellite antennas act as matching systems between sources of Electro Magnetic (EM) energy and space. The goal in using antennas is to optimize this matching. Here is a list of some of the properties of antennas: 1 Field intensity for various directions (antenna pattern); 2 Total power radiated when the antenna is excited by a current/voltage of intensity (Power Flux Density); 3 Radiation efficiency which is the ratio of power radiated to the total power (Radiation Pattern); 4 The input impedance of the antenna for maximum power transfer (matching); and 5 The antenna bandwidth or range of frequencies over which these properties are nearly constant. However, spacecraft antennas can also be classified as electrical devices which convert electric currents into radio waves and vice-versa. They are generally used with a radio transmitter and receiver, which are broadly classified in two categories: Transmitting and Receiving antennas. The difference is in the mode of operation, different functions etc. as the transmitting as well as the receiving antenna, and also difference is mainly in their environmental conditions which lead to their different designs. Typically an antenna has an array of metallic conductors that are electrically connected. An oscillating current of electrons focused through the antenna by a transmitter creates an oscillating electric field. These fields are time-varying and radiate from the antenna into the space as a moving electromagnetic field wave. Certain properties of antennas such as directional characters result into reciprocity theorem. The different types of spacecraft antennas are: 1 Wire Antennas (Monopoles and Dipoles) - The dipole is one of the most common used antennas. This spacecraft antenna consists of a straight conductor excited by a voltage from a transmission line or a waveguide and dipoles are easy to make, shown in Figure 2 (A). Wire satellite antennas are used primarily at VHF and UHF-band to provide communications for the Telemetry, Tracking and Command (TT&C) systems. They are positioned with great care on the body of the satellite in an attempt to provide omnidirectional coverage. Most satellites measure only a few wavelengths at VHF frequencies, which make it difficult to get the required antenna patterns, and there tend to be some orientations of the satellite in which the sensitivity of the TT&C system is reduced by nulls in the antenna pattern. 2 Aperture Antennas (Horn Antennas) - A horn is an example of an aperture antenna, which are used in Satellite spacecraft more commonly, shown in Figure 2 (B). Rectangular horn antenna is one of the simplest and most widely used antennas. Horns have been used for more than a hundred years, and today they used in radio astronomy, satellite communications, in communication dishes as feeders, in measurements, etc. Horn antenna is used at MW when for global coverage relatively wide beams are required. A horn is a flared section of waveguide that provides an aperture several wavelengths wide and a good match between the waveguide impedance and free space. It is also used as feeds for reflectors, either singly or in clusters. Horns and reflectors are examples of aperture antennas that launch a wave into free space from a waveguide. It is difficult to obtain gains much greater than https://www.w3.org/1998/Math/MathML"> 23   d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or beamwidths narrower than about https://www.w3.org/1998/Math/MathML"> 10 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with horn antennas. For higher gains or narrow beamwidths a reflector antenna or array must be used. 3 Reflector Antennas - The parabolic reflector is a good example of reflectors at microwave frequencies, shown in Figure https://www.w3.org/1998/Math/MathML"> 2 © https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In the past, parabolic reflectors were used mainly in space applications onboard spacecraft but today they are very popular and are used by almost everyone who wishes to receive the large number of television channels transmitted all over the globe. Manual: by Ilcev [3] Reflector antennas are typically used when very high gain or a very narrow main beam is required. Gain is improved and the main beam narrowed with increase in the reflector size. Large reflectors are however difficult to simulate as they become very large in terms of wavelengths. Reflector antennas are usually illuminated by one or more horns and provide a larger aperture than can be achieved with a horn alone. For maximum gain, it is necessary to generate a plane wave in the aperture of the reflector. This is achieved by choosing a reflector profile that has equal path lengths from the feed to the aperture, so that all the energy radiated by the feed and reflected by the reflector reaches the aperture with the same phase angle and creates a uniform phase front. One reflector shape that achieves this with a point source of radiation is the paraboloid, with a feed placed at its focus. The paraboloid, however, is the basic shape for most reflector antennas, and is commonly used for earth station antennas. Satellite antennas often use modified paraboloidal reflector profiles to tailor the beam pattern to a particular coverage zone. Phased array antennas are also used on satellites to create multiple beams from a single aperture, and have been used by Iridium and Globalstar to generate up to 16 beams from a single aperture for their LEO system. 4 Array Antennas - A grouping of several similar or different antennas form a single array antenna, shown in Figure 2 (D). The control of phase shift from element to element is used to scan electronically the direction of radiation. Antenna arrays are able to produce radiation patterns that combined, have characteristics that a single antenna would not. The antenna elements can be arranged to form a 1 or 2 dimensional antenna array. A number of antenna array specific aspects will be outlined using 1 dimensional arrays for simplicity reasons. Antennas exhibit a specific radiation pattern, which overall radiation pattern changes when few antenna elements are combined in an array. The array factor quantifies the effect of combining radiating elements in an array without the element specific radiation pattern taken into account. The overall radiation pattern results in a certain directivity and thus gain linked through the efficiency of directivity. Directivity and gain are equal if the efficiency is https://www.w3.org/1998/Math/MathML"> 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 5 Loop Antennas - A loop of wire is used to radiate or receive electromagnetic energy. These antennas can be also used at home to capture signals of Radio or TV channels, shown in Figure 2 (E). An antenna pattern is a plot of the field strength in the far field of the antenna when a transmitter drives the antenna. The gain of an antenna is a measure in dB of the antenna's capability to direct energy in one direction, rather than all around. A useful principle in antenna theory is reciprocity, which means that an antenna has the same gain and pattern at any given frequency whether it transmits or receives. An antenna pattern measured when receiving is identical to the pattern when transmitting. As stated earlier, the antenna is providing global, spot and multiple beam coverages, but it can provide scanning and orthogonally polarized beams or coverage zones as well. The pattern is frequently specified by its https://www.w3.org/1998/Math/MathML"> 3 - d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> beamwidth, the angle between the directions in which the radiated (or received) field falls to half the power in the direction of maximum field strength. However, a satellite antenna is used to provide coverage of a certain area or zone on the Earth's surface, and it is more useful to have contours of antenna gain with maximum strengths of the signal in the middle of the coverage area and with decreasing of signals to the peripheries. When computing the signal power received by an GES from the satellite, it is important to know where the station lies relative to the satellite transmit antenna contour pattern, so that the exact EIRP can be calculated. If the pattern is not known, it may be possible to estimate the antenna gain in a given direction if the antenna boresight or beam axis direction and its beamwidth are known. All parts of spacecraft antennas, which have to be aligned normally are reflector (main reflector and sub reflector), feed and sometimes also support structures. These substructures allow a pre-assembly of reflectors and feeds subsystem level and an easier integration of the complete antenna onboard spacecraft. The goal of the alignment is to bring all the antenna components in a proper geometric configuration and to get the best or at least the designed RF antenna performance in the test facility and later on in the satellite orbit https://www.w3.org/1998/Math/MathML"> [ 1,2 , 3,5 , 6 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The antenna array system of Inmarsat-2 satellite for https://www.w3.org/1998/Math/MathML"> M S C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is illustrated in Figure 3 (A). The satellite antenna system mounted on the spacecraft structure, similar to the transponders, is composed of two main integrated elements: the C/L-band and the L/C-band antenna. 1 Inmarsat-2 https://www.w3.org/1998/Math/MathML"> C / L - b a n d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Arrays - This uplink is actually the feeder link, which operates in the 6 https://www.w3.org/1998/Math/MathML"> G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> RF range. The signals sent by LES are detected by a C-band receiving array, comprising seven cup-dipole elements in the smallest circle. On the other hand, the L-band transmit antenna is the biggest segment of the whole system, consisting in 43 individual dipole elements, arranged in three rings around a single central element. Thus, this antenna is providing nearglobal coverage service downlink for MES in the https://www.w3.org/1998/Math/MathML"> 1.5 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> RF spectrums. 2 Inmarsat-2 L/C-band Arrays - These arrays is actually the service uplink and operates in the 1.6 https://www.w3.org/1998/Math/MathML"> G H z R F https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> range. The signals sent by https://www.w3.org/1998/Math/MathML"> M E S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in adjacent global coverage region are detected by L-band receiving array, comprising nine cupdipole elements arranged in a circle. Finally, the C-band transmit antenna consists in seven cupdipoles for radiation of the feeder downlink to LES in the https://www.w3.org/1998/Math/MathML"> 3.6 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> RF spectrum. 38. 3.1 Characteristics of Satellite Antennas Both transmit antenna array systems are providing a global (wide) footprint on the Earth's surface. However, narrow circular beams from GEO or NonGEO can be used to provide spot beam coverage. For instance, from GEO the Earth subtends an angle of 17.40. Antenna beams 5.80 wide can reuse three frequency bands twice in providing Earth disc coverage. The directional properties of antenna arrays can be exploited to permit RF reuse in space communications, which is similar to several radio stations using the same RF being geographically far apart. Earth coverage by seven spot beams (six spots are set out around one spot in the centre) can be arranged by three pairs of beams: 1 and 4,2 and 5 and 3 and 6 , operating on frequencies https://www.w3.org/1998/Math/MathML"> f 2 , f 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> f 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , respectively. Mutual interference within pairs is avoided by pointing one beam as far away from the other as possible. Coverage of the centre of the disc is provided by a single beam operating on frequency fl. The main advantage with this spot footprint that is specific Earth areas can be covered more accurately than with wide beams. Furthermore, a greater power density per unit area for a given input power can be achieved very well, when compared with that produced by a global circular beam, leading to the use of much smaller receiving MES antennas. The equation that determines received power (PR) is proportional to the power transmitted (PT) separated by a distance ®, with gain of transmit antenna (GT) and effective area of receiving antenna (AR) and inverse proportional with https://www.w3.org/1998/Math/MathML"> 4 π https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and square of distance. The relations for PR and GT are presented as follows: https://www.w3.org/1998/Math/MathML"> P R = P T G T A R / 4 π R https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> G T = 4 π A T T λ 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where GT https://www.w3.org/1998/Math/MathML"> = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> effective area of transmit antenna and λ = wavelength. The product of PT and GT is gain, generally as an increase in signal power, known as an EIRP. Signal or carrier power received in a link is proportional to the gain of transmit and receive antennas (GR) presented as: https://www.w3.org/1998/Math/MathML"> P R = P T G T G R λ 2 / ( 4 π R ) 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or https://www.w3.org/1998/Math/MathML"> P R = P T G T G R / L P P L K [W]   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The last relation can be derived with the density of noise power giving: https://www.w3.org/1998/Math/MathML"> P R / N = P T G T G R / T R 1 / K L P L L K https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where LP = coefficient of energy loss in free space, https://www.w3.org/1998/Math/MathML"> L K = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> coefficient of EMW energy absorption in satellite channels, https://www.w3.org/1998/Math/MathML"> T R = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> temperature noise of receiver, GR/TR is the figure of merit and K= Boltzmann's Constant https://www.w3.org/1998/Math/MathML"> ( 1.38 × 10 - 23   J / K https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or its alternatively value is https://www.w3.org/1998/Math/MathML"> - 228.6 d B W / K / H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). At any rate, PR has a minimum allowable value compared with system noise power (N), i.e., the Carrier and Noise https://www.w3.org/1998/Math/MathML"> ( C / N ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or Signal and Noise https://www.w3.org/1998/Math/MathML"> ( S / N ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ratio must exceed a certain value. This may be achieved by a trade-off between EIRP (PT GT) and received antenna gain https://www.w3.org/1998/Math/MathML"> ( G R ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . If the receive antenna on the satellite is very efficient, the demands on the LES/MES are minimized. Similarly, on the satelliteto-Earth link, the higher the gain of the satellite transmit antenna, the greater the EIRP for a given transmitter power. Satellites often have parabolic dish antennas, though there are also other types, such as phased arrays. The principal property of a parabolic reflector is its ability to turn light from a point source placed at its focus into a parallel beam, mostly as illustrated in Figure 3 (B). In practice the antenna beam can never be truly parallel, because rays can also be fan-shaped, namely a car headlamp is a typical example. In a microwave antenna the light source is replaced by the antenna feed, which directs waves towards the reflector. The length of all paths from feed to aperture plane via the reflector is constant, irrespective of their angle of parabolic axis. The phase of the wave in the aperture plane is constant, resulting in maximum efficiency and gain. In such a way, the gain of an aperture (Ga) and parabolic (Gp) type of antennas are: https://www.w3.org/1998/Math/MathML"> G a = η 4 πA / λ 2 = 4 πAE / λ 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> G p = η ( π D ) 2 / λ 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where antenna values η= efficiency factor, A= projected area of antenna aperture, https://www.w3.org/1998/Math/MathML"> A E = η A https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is effective collecting area and D= parabolic antenna diameter. Thus, owing to correlation between frequency and wavelength, https://www.w3.org/1998/Math/MathML"> f = c / λ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is given the following relations: https://www.w3.org/1998/Math/MathML"> G P = η ( π Df / c ) 2 = 60,7 D f 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where the second relation comes from considering that https://www.w3.org/1998/Math/MathML"> η ≈ 0.55 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of numerical value. If this value is presented in decibels the gain of antenna will be calculated as follows: https://www.w3.org/1998/Math/MathML"> G T = 10 l o g ⁡ G p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> For example, a satellite parabolic antenna of https://www.w3.org/1998/Math/MathML"> 2   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in diameter has a gain of https://www.w3.org/1998/Math/MathML"> 36   d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for a frequency at 4 https://www.w3.org/1998/Math/MathML"> G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and a gain of https://www.w3.org/1998/Math/MathML"> 38   d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for a frequency at https://www.w3.org/1998/Math/MathML"> 6 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In such a way, satellite parabolic antennas can have aperture planes that are circular, elliptical or rectangular in shape. Thus, satellite antenna with circular shape and homogeneous illumination of aperture with a gain of https://www.w3.org/1998/Math/MathML"> - 3   d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> has about https://www.w3.org/1998/Math/MathML"> 47.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of effective radiation, while the rest of the power is lost. To find out the ideal characteristics it is necessary to determine the function diagram of radiation in the following way: https://www.w3.org/1998/Math/MathML"> F δ 0 = s δ 0 / s δ 0 = 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where parameter https://www.w3.org/1998/Math/MathML"> s ( δ 0 ) = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> flow density of radiation in the hypothetical satellite angle https://www.w3.org/1998/Math/MathML"> ( δo ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> s ( δo = 0 ) = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> flow density in the middle of the coverage area. Looking the Geometric Projection of Satellite the relation can be presented by the equation: https://www.w3.org/1998/Math/MathML"> F δ 0 = d 0 / h = c o s ⁡ δ k 2 - s i n 2 ⁡ δ 0 / l - k https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where, as mentioned, https://www.w3.org/1998/Math/MathML"> k = R / ( R + h ) = s i n ⁡ δ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and if δo https://www.w3.org/1998/Math/MathML"> = δ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the relation is defined by the following equation: https://www.w3.org/1998/Math/MathML"> F ( δ ) = k c o s ⁡ δ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> For GEO satellite the value of ΔL is given as a function of angle δ, which is the distance from the centre of the coverage area, where the function diagram of the radiation is as follows: https://www.w3.org/1998/Math/MathML"> F ( δ ) = Δ L = 20 l o g = 20 l o g ⁡ R / R + h ) c o s ⁡ δ = 10 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> l o g ⁡ R / ( 1 + 2 R / h )   [ d B ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Therefore, in the case of GEO satellites the losses of antenna propagation are greater around the periphery than in the centre of the coverage area for about 1.32 dB. The free-space propagation loss (LP) and the input level of received signals (LK) are given by the equations: https://www.w3.org/1998/Math/MathML"> L p = ( 4 πd / λ ) 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> P R / S = P T G T / 4 π d 2   L K https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The free-space radio propagation loss is caused by geometrical attenuation during propagation from the satellite transmitter to the receiver https://www.w3.org/1998/Math/MathML"> [ 1,2 , 6,7 , 8,9 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Figure 4. Global Monobeam and Multibeam Antenna Coverage - Courtesy of Book: by Maral [4] 39. LINK PERFORMANCE WITH MONOBEAM As stated earlier, the most important parameter of spacecraft transponder and the overall RF link quality depends on the gain of the satellite antenna. From equation https://www.w3.org/1998/Math/MathML"> ( 6 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , it can be seen that the satellite antenna gain is constrained by its beamwidth, whatever the frequency at which the link is operated. So the antenna gain is imposed by the angular width of the antenna beam covering the zone to be served. If the service zone is covered using a single antenna beam, this is referred to as single or monobeam beam satellite coverage, which displays one of these characteristics:

The satellite may provide coverage of the whole region of the Earth, which is visible from the satellite as a global coverage and thus permit long-distance links to be established, for example from one continent to another with https://www.w3.org/1998/Math/MathML"> 20   d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bandwidth. In this case, the gain of the satellite antenna is limited by its beamwidth as imposed by the coverage.

The satellite may provide coverage of only part of the earth (a region or country) by means of a narrow beam (a zone or spot beam), with https://www.w3.org/1998/Math/MathML"> 3   d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> beamwidth of the order of https://www.w3.org/1998/Math/MathML"> 1 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to a few degrees.

With single beam antenna coverage, it is therefore necessary to choose between either extended coverage providing service with reduced quality to geographically dispersed GES terminals, or reduced coverage providing service with improved quality to geographically concentrated GES terminals. Multibeam antenna coverage allows these two alternatives to be reconciled. However, satellite extended coverage may be achieved by means of the juxtaposition of several narrow beam satellite coverages, which each beam providing an antenna gain which increases as the antenna beamwidth decreases (reduced coverage per beam). The link performance improves as the number of beams increases; the limit is determined by the antenna technology, whose complexity increases with the number of beams, and the mass. The complexity originates in the more elaborate satellite antenna technology and the requirement to provide on-board interconnection of the coverage areas, so as to ensure within the satellite payload routing of the various carriers that are unlinked in different beams to any wanted destination beam In Figure 4 (A) is presented that a satellite provides global coverage with a single satellite beam (monobeam) of beamwidth and in Figure 4 (B) is illustrates that satellite supports spot beams with beamwidth of a consequently reduced coverage, known as multibeam satellite coverage. In both cases, all GES terminals in the satellite network are within the correspondent satellite coverage or in LOS with satellite. Multibeam coverage is providing the following advantages:

Impact on the Earth Segment - The satellite communication link performance is evaluated as the ratio of the received carrier power C to the noise power special density NO and is quoted as the C/N0 ratio, expressed in Hz. The expression for https://www.w3.org/1998/Math/MathML"> ( C / N 0 ) U https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for the uplink (U) is given by the following equation:

Global coverage https://www.w3.org/1998/Math/MathML"> θ 3   d B = 17.5 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which implies https://www.w3.org/1998/Math/MathML"> ( G R ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> satellite https://www.w3.org/1998/Math/MathML"> = 29000 / ( θ 3   d B ) 2 ≈ 20 d B i https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .

Spot beam coverage https://www.w3.org/1998/Math/MathML"> θ 3   d B = 1.75 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which implies (GR)satellite https://www.w3.org/1998/Math/MathML"> = 29000 / ( θ 3   d B ) 2 ≈ 40 d B i https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The expression for (C/N0)D for the downlink (D) is given by:

Global coverage https://www.w3.org/1998/Math/MathML"> θ 3   d B = 17.5 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which implies (GT) satellite https://www.w3.org/1998/Math/MathML"> = 29000 / ( θ 3   d B ) 2 ≈ 20 d B i https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .

Frequency Reuse - Frequency reuse consists of using the same frequency band several times in such a way as to increase the total capacity of the satellite network without increasing the allocated bandwidth (B). In the case of a multibeam satellite the isolation resulting from antenna directivity can be exploited to reuse the same frequency band in separate beam coverages.

Interconnection by transponder hopping (no on-board processing);

Interconnection by onboard spacecraft switching (transparent and regenerative processing); and - Interconnection by beam scanning.

Multibeam satellite systems make it possible to reduce the size of GES terminal and hence the cost of the Earth segment infrastructure. Frequency reuse from one satellite beams to other permits an increase in capacity without increasing the bandwidth allocated to the system. Courtesy of Book: by Swan [6] However, interference between adjacent satellite channels, which occurs between beams using the same frequencies, limits the potential capacity increase, particularly as interference is greater with earth stations equipped with small antennas. The simplest form of a payload with multibeam antenna radiation is illustrated in Figure 5. A threetransponder payload uses one transponder per coverage circle. At this point, there is not connectivity between satellite coverage areas in this simple transponder. However, this payload could be designed so each transponder antenna illuminates three coverage circles and provide connectivity, but would cover three times area with just one-third the gain. The relatively simple changes to multiple small beams have significant consequences as: 1 The area covered by each beam is much smaller, increasing the satellite antenna gain and allowing smaller and less expensive ground and mobile terminals; 2 The same total RF power can be used to carry more traffic, and/or reduce the RF power; 3 The same transponder bandwidth can be used multiple beam antennas, greatly increasing the available bandwidth of the satellite:

This allow the same bandwidth to be reused, increasing the amount that can be accommodated within the bandwidth; and

A terminal has to be tuned to the correct RF to function and retuned if it is moved.

4 Connectivity between beams, if required for the mission, must be provided by additional hardware on the satellite since a single uplink does not encompass the entire coverage area. The satellite beams may be formed by individual feeds (circles) and by mechanical or electronic satellite beam former. However, mechanical beam formers use fixed wave-guide components to control the RF phase and amplitude. Usually there is one amplifier for each transponder in each composite beam. Electronic beam formers use electronic RF phase shifters, and sometimes provide electronic amplitude control, to produce the multibeam. There are many radiating elements and each usually has its own amplifier. [6] Satellite antenna radiators fall into two categories, reflector and direct radiating antennas. Reflector antenna uses a feed that indirectly radiates the energy towards the illuminated area of users, while direct radiating antenna radiates the energy direct to the coverage area. The satellite spot beam antenna can be pointed in various directions within a cone characterized by the scan angle, which illustrated in Figure 6 . In this way, a direct radiating array can radiate at large scan as illustrated in Figure 6. Such arrays are attractive for LEO communication satellites because they operate over large scan angle than reflectors antenna, so they requires a scan angle of https://www.w3.org/1998/Math/MathML"> 63 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to cover its field of view. In contrary, a GEO communication satellite requires a scan angle of https://www.w3.org/1998/Math/MathML"> 7 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to cover the entire visible coverage circle on the Earth surface. In addition to the fact that satellite antenna gain decreases as much the scan angle increases, and including polarization purity decreases as well. In such a way, the LEO satellite constellations require a direct radiating antenna. No commercial GEO satellite currently uses this antenna, while reflector antennas. At MEO the situation is less clear and both direct radiating and reflector antennas have been proposed for this orbit https://www.w3.org/1998/Math/MathML"> [ 1,6 , 12,13,14 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 40. CONCLUSION The design and configuration of spacecraft antenna systems for MSS needs to be compact and robust especially for global coverage beam. Spacecraft mounted payloads usually require very accurate tracking performance capabilities for all mobile applications. For example, a spacecraft mounted flexible antenna applies high accuracy and precision control to perform its mission serving ships, land vehicles and aircraft. The precision and accuracy is necessary to achieve the desired performance typically requires the use of a high gain feedback control system and accurate plant knowledge. On the other hand, the physical characteristics of antennas for ships and aircraft applications may be quite different, but both have to be designed compact for harsh environments and very extreme operating temperatures. These requirements will be difficult to achieve because the compact antenna has two major electrical disadvantages such as low gain and wide beam coverage, and because directional antenna has very heavy components for satellite tracking and getting satellite in the focus. However, a new generation of powerful satellite constellations with values of high EIRP and G/T performances should permit the design of compact and lightweight mobile satellite antennas. The current Inmarsat-4 Spacecraft user link or mobile antenna system consists of a 9 meters deployable reflector and a feed array with 120 helical elements. Over 220 simultaneous RF beams are created by applying vector weights to the feed elements under the control of the onboard Digital Signal Processor (DSP). The simultaneous transmission and reception requires the achievement of very low levels of Passive Inter-Modulation (PIM). The mission requires continuous coverage over fixed ground cells for orbital inclinations of up to https://www.w3.org/1998/Math/MathML"> 3 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This is achieved by uploading modified beam weights on a daily basis. This requires a large number of beam weights to be pre-synthesized. In addition to the pervious, the Inmarsat team has placed a contract for the procurement of a fifth generation spacecraft system to fulfill the modern communications requirements of mobile terminal users worldwide into the 21 st century. The system requirements for the Inmarsat- 5 antenna systems onboard spacecraft is to service the projected communications capacity needs, focusing upon the L,C and Ka-band antenna system requirements which are one of the key technology development areas of the program. The critical technology aspects of the antenna design needed to provide efficient implementation of the system requirements such as global and spot coverages for Voice, Data and Vide (VDV) and VDVoIP transmissions over the globe up to 750 of Elevation angles on North and South latitudes. 41. REFERENCES [1] Ilcev D. S., "Global Mobile Satellite Communications for Maritime, Land and Aeronautical Applications", Springer, Boston, 2005 . [2] Gallagher B. "Never Beyond Reach", Book, Inmarsat, London, 1989. [3] Ilcev D. S., "Global Mobile CNS", Manual, DUT, 2011. [4] Maral G. & Other, "Satellite Communications Systems", Wiley, Chichester, 2009 [5] Ilcev D. S., "Global Aeronautical Communications, Navigation and Surveillance (CNS)", Volume 1 & 2, AIAA, Reston, 2013. [6] Swan P.A. & Other, "Global Mobile Satellite Systems: A Systems Overview", Kluwer AP, Boston, 2003 . [7] Rudge A.W. & Others, "The Handbook of Antenna Design", Volume 1 & 2, IEE, London, 1986 . [8] Kantor L.Y. & Others, "Sputnikovaya svyaz i problema geostacionamoy orbiti", Radio i svyaz, Moskva, 1988. [9] Maini A.K. & Agrawal V., "Satellite Technology Principles and Applications", Wiley, Chichester, 2007. [10] Stacey D., "Aeronautical Radio Communication Systems and Networks", Wiley, Chichester, 2008 . [11] Kadish J.E. & Other, "Satellite Communications Fundamentals", Artech House, Boston-London, 2000. [12] Richharia M., "Mobile Satellite Communications Principles and Trends", Addison-Wesley, Harlow, 2001. [13] Ohmory S., Wakana. H & Kawase S. "Mobile Satellite Communications", Artech House, Boston, 1998 . [14] Zhilin V.A., "Mezhdunarodnaya sputnikova sistema morskoy svyazi - Inmarsat", Sudostroenie, Leningrad, 1988. Synthesis of Composite Biphasic Signals for Continuous Wave Radar V.M. Koshevyy, I.V. Koshevyy & D.O. Dolzhenko Odessa National Maritime Academy, Odessa, Ukraine Abstract Among the signals, which can be used in vessel's continuous wave (CW) radar, there is a class of discrete biphasic signals, which allows providing the ideal properties of the periodical autocorrelation function. Suggested signals have a special structure due to amplitude modulation, which is necessary to provide capability of radar with Search and Rescue Transponder (SART). The basic modes of operation of radar are also reserved. As amplitude modulation has its drawback - not efficient use of signal energy, the consideration of the signals with uniform amplitude in the class of proposed biphasic signals was provided. The Mismatched filtering were be used by means special weighting functions for obtaining the necessary correlation properties. On the base of these signals the composite signals of any length could be constructed with proper correlation properties and low sensitivity enough to Doppler shifts. Nowadays marine radar with continuous radiation attract attention of radar designers due to their possibility to reduce significantly the peak power of radiation and thus to improve environmental ecology and electromagnetic compatibility with other radio electronic devices on a vessel. Concerning to technical realization it should be noted that modern electronic technologies and digital techniques allow the processing of long duration signals. It is very important for this kind of radar the correct choice of the radiation signals and methods of their processing in the receivers. One of the possible approaches to the choice of such signals has been considered in [1]. Since the search and rescue transponder (SART) has no compression filter, for its work in the class of continuous signals it is required amplitude modulation and peak factor other than one, in particular, a class of binary signals has been presented in [2] and has the form: On the basis of this structure it was built a class of signals, which ensures to co-operate CW radar and SART. For the work of marine radar the signals with ideal correlation properties are of interest. This helps improve immunity of signals against interference such as clutter. Therefore, within the continuous discrete signals with non-uniform structure there were considered signals with zero side lobe level of periodic autocorrelation function (PAF) which are defined as follows [2]: https://www.w3.org/1998/Math/MathML"> a = | a | ⋅ e i φ a = - N - 2 2 , where   N ≥ 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> b = | b | ⋅ e i φ b = 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Such signals have a peak factor: https://www.w3.org/1998/Math/MathML"> H = S n m   2 ∑ n = 0 N - 1     S n 2 N = N ⋅ ( N - 2 ) 2 ( N - 2 ) 2 + 4 ⋅ ( N - 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> In order to reduce the peak factor there was proposed a method in https://www.w3.org/1998/Math/MathML"> [ 3,4 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> based on the known property of element-wise multiplication of signals with mutually prime periods [5]. This increases the coherence of the resulting signal. In particular, an example was presented, where the resultant signal is obtained due to the product of two signals (1) and https://www.w3.org/1998/Math/MathML"> N = N 1 ⋅ N 2 = 21 ⋅ 4 = 84 ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the peak factor has a value https://www.w3.org/1998/Math/MathML"> H = 17 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (according to the left part of (2) ). Expression for the calculation of Periodic crossambiguity function has the form https://www.w3.org/1998/Math/MathML"> χ ( k , l ) = ∑ n = 0 N - 1   w n * s ( n + k ) e i 2 πnl 4 N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , where k is the discrete interval of time and l is discrete of frequency with step https://www.w3.org/1998/Math/MathML"> Δf = 1 / 4 N T 0 ; T 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is elementary pulse duration; https://www.w3.org/1998/Math/MathML"> w n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is the filter coefficient. Below in Fig. 1 plots of three sections of the periodic ambiguity function (AF) of the signal with https://www.w3.org/1998/Math/MathML"> N = N 1 ⋅ N 2 = 21 ⋅ 4 = 84 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are shown. Fig. 1. Sections of AF of signal https://www.w3.org/1998/Math/MathML"> N = N 1 ⋅ N 2 = 21 ⋅ 4 = 84 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> : a) https://www.w3.org/1998/Math/MathML"> l = 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; b) https://www.w3.org/1998/Math/MathML"> l = 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; c) https://www.w3.org/1998/Math/MathML"> l = 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . As it can be seen from the figure, a periodic autocorrelation function has ideal correlation properties. But the product of two signals has a drawback - not enough decreasing the value of peak factor https://www.w3.org/1998/Math/MathML"> H = 9.5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which leads to a noticeable sensitivity to Doppler frequency shift, which is undesirable. Therefore we consider the option, in which we can further reduce the peak factor. To do this, we can choose the smaller parts for product https://www.w3.org/1998/Math/MathML"> N = N 1 ⋅ N 2 ⋅ N 3 = 3 ⋅ 4 ⋅ 7 = 84 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This will decrease the peak factor (according to (2)) of the signal to a value https://www.w3.org/1998/Math/MathML"> H = 4.7 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . At the same time, it is expected to reduce the side lobes of the cross sections of AF with a Doppler frequency shift. Figure 2. Sections of AF of signal https://www.w3.org/1998/Math/MathML"> A - M L ⋅ N 2 ⋅ M 2 - 8 ⋅ ± ⋅ 7 - 8 + : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a) https://www.w3.org/1998/Math/MathML"> l = 0 ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> b) https://www.w3.org/1998/Math/MathML"> l = 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; c) https://www.w3.org/1998/Math/MathML"> l = 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> As it's expected and seen in Fig. 2 above, sensitivity to the Doppler frequency shift was reduced. The presented approach is effective and can be used for obtaining signals with long periods. Consider, for example, a signal in the form of a product of four signals: https://www.w3.org/1998/Math/MathML"> N = N 1 ⋅ N 2 ⋅ N 3 ⋅ N 4 = 4 ⋅ 5 ⋅ 7 ⋅ 9 = 1260 ( A F https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is on Figure 3) and peak factor is equal to https://www.w3.org/1998/Math/MathML"> H = 5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . d) b) N=N https://www.w3.org/1998/Math/MathML"> N = N 1 ⋅ N 2 ⋅ N 3 ⋅ N 4 = 4 ⋅ 5 ⋅ 7 ⋅ 9 = 1260 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> : a) https://www.w3.org/1998/Math/MathML"> l = 0 ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> b) https://www.w3.org/1998/Math/MathML"> l - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ;c) https://www.w3.org/1998/Math/MathML"> l = 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . ignal of long duration with a small peak factor and low sensitivity to the Doppler frequency shifts. Thus, we can widely modify the peak factor of signals (1), obtaining an ideal correlation properties in the AF zero section, and with an increase in the coherent part of the signal we can reduce the side lobes of AF. Further increasing of segments of resulting signal will lead to an increase in the peak factor. For the individual modes of radar let's consider the case when the peak factor is one: https://www.w3.org/1998/Math/MathML"> H = 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In this case, the form of the signal is determined according to: https://www.w3.org/1998/Math/MathML"> [ abb … b ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , where https://www.w3.org/1998/Math/MathML"> a = - 1 ,  b = 1 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Thus to provide ideal properties of periodic autocorrelation function it can be used mismatched processing that is development of an approach described in [4]. The filter coefficients can be calculated according to the expression found: https://www.w3.org/1998/Math/MathML"> w 0 = a ( a + N - 1 ) - 2 a - ( N - 2 ) 1 - a ;   w n = 1   ( n = 1 ÷ N - 1 ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Arising some losses in signal-to-noise ratio can be found from the following expression: https://www.w3.org/1998/Math/MathML"> ρ = [ a [ a ( a + ( N - 1 ) ) - 2 a - ( N - 2 ) ] + ( N - 1 ) ( 1 - a ) ] 2 [ a ( a + ( N - 1 ) ) - 2 a - ( N - 2 ) ] 2 + ( N - 1 ) ( 1 - a ) 2 ⋅ a 2 + ( N - 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> If https://www.w3.org/1998/Math/MathML"> a = - N - 2 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , then there has no losses in signalto-noise ratio https://www.w3.org/1998/Math/MathML"> 2 2 ρ = 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . If https://www.w3.org/1998/Math/MathML"> a = - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; then the losses in signal-to-noise ratio can be calculated from the relation: https://www.w3.org/1998/Math/MathML"> ρ = 4 ⋅ ( N - 2 ) 2 ( N - 3 ) 2 + ( N - 1 ) ⋅ N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> As an example there is a signal (4) when https://www.w3.org/1998/Math/MathML"> N = 9 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and on the Figure 4 there is cross-ambiguity function (CAF) of it. Figure 4. CAF of signal (2) https://www.w3.org/1998/Math/MathML"> N = 9 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Here is an example where the resulting product signal is composed of signals (4) with relatively prime periods https://www.w3.org/1998/Math/MathML"> N = N 1 ⋅ N 2 ⋅ N 3 ⋅ N 4 = 4 ⋅ 5 ⋅ 7 ⋅ 9 = 1260 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The value of the loss in signal-to-noise ratio for the resulting signal will be a product of the values ρ of its component signals [6]: https://www.w3.org/1998/Math/MathML"> ρ = ρ 1 ⋅ ρ 2 ⋅ ρ 3 ⋅ ρ 4 = 1 ⋅ 0.9 ⋅ 0.65 ⋅ 0.5 = 0.29 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> A cross- ambiguity function of product of the four signals https://www.w3.org/1998/Math/MathML"> N = 4 ⋅ 5 ⋅ 7 ⋅ 9 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the case when the signals have the form https://www.w3.org/1998/Math/MathML"> [ a 11 … 1 ] a = - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is illustrated below in Figure 5 . a) b) Figure https://www.w3.org/1998/Math/MathML">   5 .   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Sections of AF of signal https://www.w3.org/1998/Math/MathML"> N T = N 1 ⋅ N 2 T ⋅ N 3 ⋅ N 4 = 4 ⋅ 5 ⋅ 7 ⋅ 9 : a l = 0 ; b l = 1 ; c l = 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> N = N 1 ⋅ N 2 ⋅ N 3 ⋅ N 4 = 4 ⋅ 5 ⋅ 7 ⋅ 9 : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a) https://www.w3.org/1998/Math/MathML"> l = 0 ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> b) https://www.w3.org/1998/Math/MathML"> l = 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; c) https://www.w3.org/1998/Math/MathML"> l = 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> However, increasing N increases the losses in signal-to-noise ratio. Thus, when https://www.w3.org/1998/Math/MathML"> N > 11 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the effectiveness of such signals will fall, because of significant losses in the signal-to-noise ratio. As possible solutions is using the additional classes of signals, including Barker codes. For example, consider a signal https://www.w3.org/1998/Math/MathML"> N = N 1 ⋅ N 2 ⋅ N 3 ⋅ N 4 = 4 ⋅ 5 ⋅ 7 ⋅ 13 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which includes a Barker code https://www.w3.org/1998/Math/MathML"> N 4 = 13 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The presence of positive side lobes of the correlation function at the Barker code gives low losses in signal to noise ratio https://www.w3.org/1998/Math/MathML"> ρ = 0.96 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> [7]. Resulting https://www.w3.org/1998/Math/MathML"> ρ = 0,57 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Below in Fig. 6 CAF of such signal is presented: a) b) Figure 6, Sections of MAF of signal https://www.w3.org/1998/Math/MathML"> N 1 = N 1 ⋅ N 3 ⋅ N 4 = 4 ⋅ 5 ⋅ 7 ⋅ 13 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with Barker code: a) https://www.w3.org/1998/Math/MathML"> l = 0 ; 6 ) l = 1 ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> B) https://www.w3.org/1998/Math/MathML"> ] = 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . However, the continuous mode has some difficulty in the practical implementation, since it requires the availability of two antennas on the vessel. As a solution, we can use a quasi-continuous mode [8], when the entire signal is superimposed another signal with intervals of zeros. A disadvantage of such signals is that they are not suitable for all ranges of elements. Another way is to use periodic signals of a certain duration [1], but they have a disadvantage which is a significant side-lobe level of AF equal https://www.w3.org/1998/Math/MathML"> T N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The third approach is the following: to radiate a certain signal in each period and due to complementarity zero side lobes of resulting aperiodic cross-corrnelation function will be provided. Thus, based on the considered signals are constructed composite signals of arbitrary length with suitable correlation properties and different peak factors, and in particular equal to unity with low sensitivity to the Doppler shift. 42. REFERENCES [1] V. M. Koshevyy, D. O. Dolzhenko. The Selection of Signals which Enable Continuous Wave Radar in Conjunction with Existing SART [in Russian], Navigation (Судовождение), Odessa: ONMA, №21, 2012, pp124-129. [2] V. M. Koshevyy, D. O. Dolzhenko. The Synthesis of Periodic Sequences with Given Correlation Properties // Proc. of IEEE East-West Design & Test Symposium (EWDTS'11), Sevastopol, Ukraine, September 9-12, 2011. - P. 341-344. [3] V. M. Koshevyy, D. O. Dolzhenko. Selection of Signals for Continuous Wave Radar [in Russian], Automation of ship technical aids, Odessa: ONMA, No18, 2012, pp. 63-73. [4] V. M. Koshevyy, D. O. Dolzhenko, The Signals of Marine Continuous Radar for Operation with SART, 10th International Navigational Symposium on "Marine Navigation and Safety of Sea Transportation" TRANSNAV 2013, Gdynia. [5] R. C. Titsworth, Correlation properties of cyclic sequences, Ph. D. Thesis, Calif. Inst. Tech., 1962. [6] V. P. Ipatov, Periodic Discrete Signals with Optimal Correlation Properties, Radio I Svyaz, Moscow, 1992 [7] V. M. Koshevyy, A. O. Shapovalova,Optimization of filters for Periodic Cross-Ambiguity function side lobes for Periodic Cross-Ambiguity function side lobes Navigation (Судовождение), Odessa: ONMA, №20, 2011, Navigation 8] Pat. USA No 3727222 . Zero Levels Formation of Radiation Pattern Linear Antennas Array with V.M. Koshevyy & A.A. Shershnova Odessa National Maritime Academy, Ukraine Abstract The algorithm of radiation pattern linear antennas array formation for vessel's radar is suggested. Only two controlling elements of array are needed for obtaining practically full rejection of side lobe level of pattern linear antenna array at any azimuth angle outside the main lobe area. This gives the possibility separation of signals from vessels with big and small Target Cross Sections, equals range and close azimuth angels. The results of Radiation Pattern calculations for different situations are given. The possibility of twinning of rejection points are shown. The modern radars are the high-powered technical mean of navigation and take important part to ensure maritime safety. But they aren't free from lots of drawbacks. The sufficient side lobes level of ship's radar antenna array diagram is the one of such drawback. It's lay to impossibility of separate signal observation from the big vessel (which has big effective reflecting surface (ERS)) and from small vessel, which has small ERS, and which are situated on the same distance and have azimuth angle's close value. The solution of this problem can be received in ship radar antenna pattern formation with using linear antenna array with controlled elements. The optimal methods of formation such diagrams are known and associated with the need of all array elements tuning by difficult algorithms [5]. At the same time the reaching of antenna pattern side lobes required suppression level may be with the simple methods by using the arrays with limited number of tunable weight coefficients of spatial filter (antenna array elements), for example, when there are only two of such tunable weight coefficients. In this case all of the receiving antenna array of spatial filter's weights coefficients https://www.w3.org/1998/Math/MathML"> W i https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the processing, except two (first and last : https://www.w3.org/1998/Math/MathML"> W 1 , W N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ), are fixed (selected under the condition of providing the required antenna pattern side lobe's level) https://www.w3.org/1998/Math/MathML"> W 2 ; W 3 ; … ; W N - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Value of the two tunable weights coefficients are selected for carried out the condition of providing zero values in two points https://www.w3.org/1998/Math/MathML"> θ 1 , θ 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the reception pattern. The expressions, which are describing the reception pattern of linear array antenna https://www.w3.org/1998/Math/MathML"> G ( θ ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for this case, may be written in the following form: https://www.w3.org/1998/Math/MathML"> G ( θ ) = G N - 2 ( θ ) - γ 1 ( θ ) ⋅ G N - 2 θ 1 - - γ 2 ( θ ) ⋅ G N - 2 θ 2 = ∑ i = 1 N   W 2 ⋅ e - j 2 π ( N - 1 ) d λ s i n ⁡ θ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where https://www.w3.org/1998/Math/MathML"> G N - 2 ( θ ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - partial diagram, https://www.w3.org/1998/Math/MathML"> G N - 2 ( θ ) = ∑ l = 2 N - 1   W i + e - j 2 π ( N - 1 ) d 2 s i n ⁡ θ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> γ 1 ( θ ) = e j 2 π ( N - 1 ) d d s i n ⁡ θ 2 - e - j 2 π ( N - 1 ) d λ s i n ⁡ θ e j 2 π ( N - 1 ) d λ s i n ⁡ θ 2 - e j 2 π ( N - 1 ) d A s i n ⁡ θ 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> γ 2 ( θ ) = e - j 2 π ( N - 1 ) d λ s i n ⁡ θ - e - j 2 π ( N - 1 ) d λ s i n ⁡ θ 1 e j 2 π ( N - 1 ) d A s i n ⁡ θ 2 - e j 2 π ( N - 1 ) d i s i n ⁡ θ 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> φ = 2 π d s i n ⁡ θ λ = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> signal phase; λ= wave's length; d= distance between antenna's array elements, θ= angle between the normal to the axis of the array antenna and direction of coming signal. https://www.w3.org/1998/Math/MathML"> ( N - 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> fixed weight coefficients may selected under condition of additional suppression average level of reception diagram's side lobes (2) with possible widening the main lobe of antenna array (1). So, the full number of the coefficients, which creates reception array diagram, is equal N. The expression for fixed weight coefficients has the next form[4]: https://www.w3.org/1998/Math/MathML"> W f = D - 1 ⋅ 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where https://www.w3.org/1998/Math/MathML"> D - 1 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> inverse matrix; 1- identity columnvector, which consists of all unit numbers; Matrix D is formed as follows: https://www.w3.org/1998/Math/MathML"> D = ∑ L 1 L 2   1 ⋅ Q l ⋅ 1 t ⋅ Q l * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where https://www.w3.org/1998/Math/MathML"> Q l - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> diagonal matrix: https://www.w3.org/1998/Math/MathML"> Q l = e j 2 l 2 π d λ s i n ⁡ Δθ 0 0 … . 0 0 e j 3 / 2 π d λ s i n ⁡ Δθ 0 … 0 0 0 0 … … e j ( N - 1 ) / 2 π d λ s i n ⁡ Δθ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> Δ θ f = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> an interval, between suppressing points of the spatial diagram https://www.w3.org/1998/Math/MathML"> G N - 2 ( θ ) ; 1 ' = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> transposed matrix; https://www.w3.org/1998/Math/MathML"> L 1 , L 2 = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> upper and lower bounds for suppressed points. Choosing in https://www.w3.org/1998/Math/MathML"> Q l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (5) step https://www.w3.org/1998/Math/MathML"> Δ θ f https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and also values https://www.w3.org/1998/Math/MathML"> L 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> L 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> we can provide different values of average level of side lobes https://www.w3.org/1998/Math/MathML"> G N - 2 ( θ ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , but with varying degrees of its main lobe widening. Thus, if https://www.w3.org/1998/Math/MathML"> Δ θ i = a r c s i n ⁡ 1 2 ( d / λ ) ( N - 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (ratio https://www.w3.org/1998/Math/MathML"> d / λ = 0,5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was set everywhere), https://www.w3.org/1998/Math/MathML"> L 1 = 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> L 2 = N - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> from (4), (5) we are getting the case where all https://www.w3.org/1998/Math/MathML"> W 1 = 1 ( i = 2 ÷ N - 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . That is the case of fully coherent to reception diagram https://www.w3.org/1998/Math/MathML"> G N - 2 ( θ ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (equable correction), which corresponds the condition with absence of main lobe widening (Fig.1, a). Such approach was considered in [1] and [2]. If https://www.w3.org/1998/Math/MathML"> Δ θ f = a r c s i n ⁡ 1 4 ( d / λ ) ( N - 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and https://www.w3.org/1998/Math/MathML"> L 1 = 3 , L 2 = 2 N - 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the unequal values of weight coefficients can be obtained (uneven correction), which provides compromise between average value of side lobes suppression (more than https://www.w3.org/1998/Math/MathML"> - 30   d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) and relatively small main peak's extension (about https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) (Fig.1, b). a) b) b) Figure 1. Partial reception diagram: a- with equal weight Figure 1. Partial reception diagram: a - with equal weightcoefficients values; b - with unequal weight coefficients values coefficients values; b - with unequal weight coefficients values This diagrams are showing, that average level ofsuppression with different W, less, than in case, when https://www.w3.org/1998/Math/MathML"> W 2 = W 3 = … = W N - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The expression for tunable weight coefficients has the following form: https://www.w3.org/1998/Math/MathML"> W N = G N - 2 θ 1 - G N - 2 θ 2 e j 2 π ( N - i ) d λ wn θ 2 - e j 2 π ( N - i ) d λ I θ j . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Fig. https://www.w3.org/1998/Math/MathML"> 2 , a - c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> shows the calculation by expressions (1), (2), (3) for case of common-mode processing in partial antenna (all values https://www.w3.org/1998/Math/MathML"> W 2 = W 3 = … = W N - 2 = 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). In this case: https://www.w3.org/1998/Math/MathML"> Δ θ f = a r c s i n ⁡ 1 2 ( d / λ ) ( N - 2 ) , L 1 = 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> и https://www.w3.org/1998/Math/MathML"> L 2 = ( N - 2 ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Losses in antenna's directivity to fully commonmode reception diagram: https://www.w3.org/1998/Math/MathML"> ρ = ∣ G O 2 N ∑ n = 1 N   W n 2 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a) b) b) c) Figure 2.correction): https://www.w3.org/1998/Math/MathML"> a - θ 1 = - 1.200 - θ 2 - - 1.171 ρ - - 02238 d B ; 60 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> θ 1 - - 0.8137 , θ 2 - - 0.7854 , ρ = - 0.2784 , d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> c - θ 1 = - 0.2576 , θ 2 = - 0.2293 , ρ = - 1.4107 , d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The similar type of expressions, as (6), (7) were obtained for the signal time processing in the case of frequency selection https://www.w3.org/1998/Math/MathML"> [ 1 ] , [ 6 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and the time-frequency task selection signal [7]. As we can see, the suppression of this points is high enough, and the side lobes level between the suppressed points not high (about https://www.w3.org/1998/Math/MathML"> - 80 d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). Losses in antenna's directivity (8) are increase with drawing closer to main lobe, and in considered case isn't more than https://www.w3.org/1998/Math/MathML"> - 1,4 d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . C) Figure 3. The equable correction of reception diagram (of partial diagram) with increased in twice distance between suppressed points: For comparison, on fig.3, a-c was considered the case, when the distance between suppressed points was increasing in twice. The side lobes level between suppressed points is increase, but wasn't more than https://www.w3.org/1998/Math/MathML"> - 40 - 60 d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Now let's consider the case, when: https://www.w3.org/1998/Math/MathML"> Δ θ f = a r c s i n ⁡ 1 4 ( d / λ ) ( N - 2 ) , L 1 = 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> L 2 = ( 2 N - 3 ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> That is the case, when we get unequal values of weight coefficients, which are obtained by (4), (5), which provide the compromise between level of side lobes suppression (about https://www.w3.org/1998/Math/MathML"> 30 d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) and not high main lobe widening (about 10%) (fig.4, a-c ). a) b) c) https://www.w3.org/1998/Math/MathML"> 2 2 - 1.5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - https://www.w3.org/1998/Math/MathML"> 1.0 . 5 प https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Figure 4.diagram): With the same suppressed points https://www.w3.org/1998/Math/MathML"> θ 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> и https://www.w3.org/1998/Math/MathML"> θ 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> we received less average side lobes level within the given area at the expense of some main lobe widening. It interesting to note, than if instead of reception diagram, which described by (1), we use the expression for symmetrical form with real coefficients (11), (12) in following form: https://www.w3.org/1998/Math/MathML"> G ( 1 ) ( θ ) = G ( 1 ) N - 2 ( θ ) - γ 1 ( 1 ) ( θ ) ⋅ G ( 1 ) N - 2 θ 1 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - γ 2 ( 1 ) ( θ ) ⋅ G N - 2 ( 1 ) θ 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where https://www.w3.org/1998/Math/MathML"> G N - 2 ( 1 ) ( θ ) = G N - 2 ( θ ) ⋅ e jπ ( N - 1 ) d λ s i n ⁡ θ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , We can get reception diagram with suppressing in four points with symmetrical positioning relative to main lobe. As an example, on figures https://www.w3.org/1998/Math/MathML"> ( 12 ) - ( 14 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are showed the next diagrams: a) b) https://www.w3.org/1998/Math/MathML"> η 1 ω ( θ ) = c o s ⁡ - j 2 π ( N - 1 ) d λ s i n ⁡ θ 1 c o s ⁡ - j 2 π ( N - 1 ) d λ s i n ⁡ θ 2 - c o s ⁡ - j 2 π ( N - 1 ) d λ s i n ⁡ θ 1 - c o s ⁡ - j 2 π ( N - 1 ) d d s i n ⁡ θ c o s ⁡ - j 2 π ( N - 1 ) d λ s i n ⁡ θ 1 ∣ - c o s ⁡ - j 2 π ( N - 1 ) d λ s i n ⁡ θ 1 γ 2 ( I ) ( θ ) = c o s ⁡ - j 2 π ( N - 1 ) d λ s i n ⁡ θ c o s ⁡ - j 2 π ( N - 1 ) d λ s i n ⁡ θ 2 - c o s ⁡ - j 2 π ( N - 1 ) d λ s i n ⁡ θ 1 c o s ⁡ - j 2 π ( N - 1 ) d λ s i n ⁡ θ 1 c o s ⁡ - j 2 π ( N - 1 ) d λ s i n ⁡ θ 2 ∣ - c o s ⁡ - j 2 π ( N - 1 ) d λ s i n ⁡ θ 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Figure 5. Reception diagram with real coefficients (symmetrical): https://www.w3.org/1998/Math/MathML"> a - θ 1 = - 1.2001 , θ 2 = - 1.1718 , ρ = - 1.0848 , d B ; b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - θ 1 = - 0.8137 , θ 2 = - 0.7854 , ρ = - 1.5527 , d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; https://www.w3.org/1998/Math/MathML"> c - θ 1 = - 0.2576 , θ 2 = - 0.2293 , ρ = - 2.4359 , d B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Such away, the algorithm of radiation pattern linear antennas array formation for vessel's radar is suggested, which provide high enough side lobes level suppression of reception diagram with only two controlling elements, this gives the possibility separation of signals from vessels with big and small Target Cross Sections, equals range and close azimuth angels. It's impossible to reach by using standart vessel's antennas. As in the case of equal (N-2)- weight coefficients, which forms the partial diagram, as in the case of uneven correction, it's provided zero level of side lobes within the given area with reduced average side lobe's level in case of equable correction. Wherein, the algorithm of tunable weight coefficients formation (6) and (7) are easy for practical implementation. The possibility of twinning of rejection points is shown. 1. CONCLUSIONS Nowadays the ship's radar antennas are antenna arrays, which consists N-elements as line slot antennas or loud-hailer antennas, which are situated in horizontal plane and aren't tuned. In this paper the simplified variant of controlling antenna array is offered, in which only two ultra elements are tuned - first and last, which provides the suppression of any antenna array diagram side lobe in azimuth plane. The obtained expressions for module and phase of this tuning elements are implemented by appropriate attenuators and phase shifters. It gives the control principle by way of moving the reception diagram laydowns. By removing on the control panel the appropriate controller, which connected to two tunable antenna array elements, it's possible to move the suppression zone to different azimuth angles. The attenuators and phase shifters control principle is received and can be easy realized on base of the simplest microprocessor. In cases, when the probability of fogging the small ship by the bigger one on radar screen, by the way of turning the additional controller, which is on the radar panel, the suppression of needed side lobe of reception diagram can be received. It gives the possibility of practical use of the antenna reception diagram formation proposed algorithm in the azimuth plane of ship radar for voiding the small targets from the big ones. 2. REFERENCES V. Koshevyy, V. Lavrinenko, 1981, The target's selection on based on the discrete structure with a minimum quantity of controlled elements. «Izvestia VUZ. Radioelectronika», t. 24 , №4, pp. 105-107 V. Koshevyy, A. Shershnova, 2013, The formation of zero levels of Radiation Pattern linear Antennas Array with minimum quantity of controlling elements, Proc. 9 Int. Conf. on Antenna Theory and Techniques (ICATT-13), Odessa, Ukraine, pp.264-265 V. Koshevyy, M. Sverdlik, 1974 , About the possibility of full side lobes level suppression of ambiguity function in the given area. - « Radio Eng. Electron. Phys.», t. 19, № 9 , pp. 1839-1846. V. Koshevyy, V. Lavrinenko, S. Chuprov, 1975, The efficiency of quasi-filter analysis. «RIPORT », VIMI. №2, - p. 7. Y. Shirman, V. Mandjos, 1981 , Theory and technics of radar information processing under interferences. M. Radio I Svyaz, https://www.w3.org/1998/Math/MathML"> - 416 c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . V. Koshevyy, 1982, Moving target systems indication synthesis with the inverse matrix size restrictions. «Izvestia VUZ. Radioelectronikay, T.25, № 3, C. 84-86. V. Koshevoy, M. Sverdlik, 1973 , About influence of memory and pass-band of generalized v-filter to efficiency of interference suppression. 《 Radio Eng. Electron. Phys.», t.18, №8, pp. 1618-1627. E.A. Karagianni & A.P. Mitropoulos Electronics Laboratory, Department of Naval Sciences, Hellenic Naval Academy, Hellas N.G. Drolias & A.D. Sarantopoulos Division of Climatology - Applications, Hellenic National Meteorological Service, Hellas A.A. Charantonis CEDRIC Laboratory, Conservatoire National des Arts et Metiers, Paris, France ABSTRACT: By utilizing meteorological data such as relative humidity, temperature, pressure, precipitation height and precipitation duration) at Skyros and Naxos Islands, Hellas https://www.w3.org/1998/Math/MathML"> ( 24,32 ∘ E , 38,50 ∘ N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - Skyros https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> from four recent years https://www.w3.org/1998/Math/MathML"> ( 2010 - 2013 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the effect of the weather on Electromagnetic wave propagation is studied. The EM wave propagation characteristics depend on atmospheric refractivity and consequently on Rain-Rate which vary in time and space randomly. Therefore the statistics of radio refractivity, Rain-Rate and related propagation effects are of main interest. This work investigates the differences in monthly, seasonal and daily amounts of rainfall, for every synoptic 3 and 12 -hour interval and the change of refractivity as observed in Northeastern Aegean Archipelagos. 3. INTRODUCTION 3.1. Humidity of the atmosphere Water is the only substance that can be found naturally in all three states (gas, liquid, solid) in the atmosphere. Humidity is the general term to show the existence of the "water" in the atmosphere. A number of parameters are used to expresses the humidity reveals its importance in many scientific domains. Such parameters are water vapor pressure (e), saturation vapor pressure (es), relative humidity (H), dry temperature https://www.w3.org/1998/Math/MathML"> ( θ ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , precipitation height (h), precipitation time interval (t), pressure (P), water vapor density https://www.w3.org/1998/Math/MathML"> ( ρ ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Water in any state affects the transmission of the electromagnetic wave. When the wave passes through a humid atmospheric layer, part of its energy is reflected or scattered, another is absorbed and the rest is passing without any change. Therefore the electromagnetic wave is attenuated. The attenuation is caused by the scattering and absorption of electromagnetic waves by drops of liquid water. The scattering diffuses the signal, while absorption involves the resonance of the waves with individual molecules of water. Absorption increases the molecular energy, corresponding to a slight increase in temperature, and results in an equivalent loss of signal energy. In strong precipitation phenomena (due to the movements of the "drops") in addition to the signal being attenuated, the system noise temperature is increased and the polarization is changed. These three effects cause degradation in the received signal quality. At C-band the effects are minor whilst at higher frequencies, such as Ka-band, the attenuation increases. Prediction of the influence of these factors is very important in telecommunications systems design. Attenuation due to rain can lead to the perturbations of the wireless, mobile, satellite and other communications. Rain events produce unavailability of microwave links, which may lead to economical losses or even license loosing. 4. 1.2 The raindrop Water molecules are dipoles (hydrogen bonding). The raindrop's dipoles act as an antenna with low directivity, which re-radiates the electromagnetic wave energy. Water is a loss-making dielectric medium. The relative dielectric constant of water is high, compared to the dielectric constant of the surrounding air. It depends on the medium temperature and the operating frequency of the telecommunications system. One of the problems in the prediction of electromagnetic wave power losses is the description of shape of the raindrop, strongly depended on the size. It is known, that only very small raindrops are like spheres. Such drops exist in clouds. The shape of raindrops, that are larger than 1 mm in diameter, is no more spherical. They are not tear-shaped, as it commonly presented. The shape of falling large raindrops is more like a hamburger shape. Therefore, horizontally polarized waves suffer greater attenuation than vertically polarized waves. The raindrop size distribution and the drop shape relation have great variation in different precipitation conditions. In heavy precipitation phenomena the raindrop size is composed of lots of median and small raindrops rather than giant raindrops https://www.w3.org/1998/Math/MathML"> [ 1 ] , [ 7 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Both shape and size are depending from the dynamics principles where a raindrop is deforming as it falls in air, breaking into smaller fragments. The topological change from a big drop into smaller stable fragments is accomplished within a time scale much shorter than the typical collision time between the drops https://www.w3.org/1998/Math/MathML"> [ 2 ] , [ 3 ] , [ 8 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Regarding strong precipitation phenomena, the size of a typical raindrop, is about 3 millimeters. When the wavelength approaches this length, attenuation is significant. Wavelength in free space and frequency are related by the well-known equation https://www.w3.org/1998/Math/MathML"> c = λ f https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , where λ is the wavelength, f is the carrier frequency, and https://www.w3.org/1998/Math/MathML"> c s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is the speed of the electromagnetic wave in free space https://www.w3.org/1998/Math/MathML"> c = 1 ε 0 ⋅ μ 0 ≈ 3 ⋅ 10 8 m / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where https://www.w3.org/1998/Math/MathML"> ε 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> μ 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are the free space permittivity and permeability constants in F/m and H/m respectively. For example, at the S-band of https://www.w3.org/1998/Math/MathML"> 2,4 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the wavelength is 125 millimeters in free space and thus it is 40 times larger than a raindrop and the signal passes through the rain with relatively small attenuation [4], [9]. At X-band with a frequency of https://www.w3.org/1998/Math/MathML"> 10 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the wavelength is 30 millimeters and at https://www.w3.org/1998/Math/MathML"> K a - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> band with a carrier frequency of https://www.w3.org/1998/Math/MathML"> 20 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the wavelength is 15 millimeters. At these frequencies, the wavelength and raindrop size are comparable and the attenuation is quite large. 5. 1.3 The relative refractive index When the propagation medium is a material different than air, the speed of an electromagnetic wave depends on the relative dielectric constant known as relative permittivity https://www.w3.org/1998/Math/MathML"> ε r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and to the relative permeability https://www.w3.org/1998/Math/MathML"> μ r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , with the following formula: https://www.w3.org/1998/Math/MathML"> v = 1 E ⋅ μ = c ε r ⋅ μ r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where https://www.w3.org/1998/Math/MathML"> ε = = ε 0 ε r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> μ = μ 0 μ r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , are the permittivity and permeability in F/m and H/m respectively, and https://www.w3.org/1998/Math/MathML"> ε r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> μ r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are the relative permittivity and permeability of the medium https://www.w3.org/1998/Math/MathML"> [ 6 ] , [ 11 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The relative refractive index, n is defined as https://www.w3.org/1998/Math/MathML"> n = ε r - μ r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Values for the relative refractive index, are presented in Figure 3 for four years observations in Skyros Island at Northwest Aegean Sea (Figure 2). 6. RAIN MODELS FOR WAVE ATTENUATION 7. 2.1 Rain attenuation The electromagnetic wave attenuation due to rain (the rain attenuation) is one of the most noticeable components of excess losses, especially at frequencies of https://www.w3.org/1998/Math/MathML"> 10 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and above. Considerable research has been carried out to model rain attenuation mathematically and to characterize rainfall throughout the world. The standard method of representing rain attenuation is through the power-law relationship https://www.w3.org/1998/Math/MathML"> [ 10 ] , [ 14 ] , [ 15 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . https://www.w3.org/1998/Math/MathML"> L r = k ⋅ R a ⋅ L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where https://www.w3.org/1998/Math/MathML"> L r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is the rain attenuation (in https://www.w3.org/1998/Math/MathML"> dB , R https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is the rain rate (in https://www.w3.org/1998/Math/MathML"> m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ), L is an equivalent path length (in https://www.w3.org/1998/Math/MathML"> k m ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and k and α are empirical coefficients, functions of the operating frequency (f), polarization ( kh or https://www.w3.org/1998/Math/MathML"> α h - h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for horizontal polarized waves and https://www.w3.org/1998/Math/MathML"> k v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or https://www.w3.org/1998/Math/MathML"> k v - v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for vertical polarized waves) and temperature (T). For horizontally polarized waves, kH and αH parameters are given in Table 1 for selected S and X band frequencies https://www.w3.org/1998/Math/MathML"> [ 12 ] , [ 16 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Table 1. Parameters for horizontally polarized waves (h) in S and X-band. Frequency https://www.w3.org/1998/Math/MathML"> ( G H z ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> k H x 10 - 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> α H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2,5 0,1321 1,1209 5 0,2162 1,6969 10 12,17 1,2571 The equivalent path length depends on the angle of elevation of the communication link, the height of the rain layer (h), and the latitude of the earth station. (Figure 1) The rain rate enters into equation 4 because it is a measure of the average size of the raindrops. When the rain rate increases that means it rains harder, the rain drops are larger and thus there is more attenuation. Also, the conversion of the radar reflectivity factor to rain rate is a crucial step in weather radar measurements. It has been common practice for over 60 years now to take for this conversion a simple power law relationship between them, using the classical exponential raindrop size distribution [17], [18]. 7.1. Rain Models Rain models differ principally in the way the effective path length L is calculated. Two rain models are widely used, the Crane model and the ITU-R model (International Telecommunication Union's Radio-communication sector). The twocomponent Crane model takes into account both the dense center and the fringe area of a rain cell [11], [19]. In the design of a telecommunications' link a margin is included to compensate for the effects of rain at a given level of availability. The statistical characterization of rain begins by dividing the world into rain climate zones. Within each zone, the maximum rain rate for a given probability is determined from actual meteorological data accumulated over many years. The methods of prediction of the rain attenuation can be categorized into two groups: the physical models and the empirical models. The physical models attempt to reproduce the physical behavior involved in the attenuation processes while the empirical methodologies are based on measurement databases from stations in different climatic zones within a given region. The empirical methods are used widely. The factor https://www.w3.org/1998/Math/MathML"> γ r = L r / L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (in https://www.w3.org/1998/Math/MathML"> d B / K m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ), where https://www.w3.org/1998/Math/MathML"> L r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and L are defined in equation 4 , is called the specific rain attenuation. One of the most widely used rain attenuation prediction methods is the empirical relationship between this specific rain attenuation https://www.w3.org/1998/Math/MathML"> γ r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (in https://www.w3.org/1998/Math/MathML"> d B / k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) and the rain rate R( in https://www.w3.org/1998/Math/MathML"> m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) [12], [13] https://www.w3.org/1998/Math/MathML"> γ r = k ⋅ R c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 7.2. Data Collection When it is impossible to gather data for calculations of the specific attenuation due to rain and atmospheric relative refractive index, the values recommended by the ITU-R can be used. But the recommended values are not always exact. The easiest telecommunication system design is for operating frequencies below https://www.w3.org/1998/Math/MathML"> 10 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> because for these frequencies atmospheric absorption and rainfall loss generally are neglected. Due to the fact that these bands are highly congested, in telecommunication systems design, frequencies above https://www.w3.org/1998/Math/MathML"> 10 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are often used. But, the higher the operating frequency, the greater attenuation due to hydrometeors (rain, cloud, fog, snow) is observed. In this paper, our attention would be concentrated on the attenuation due to rain using collecting data for Northwest Aegean for a period of four years. 8. RAIN RATE For the determination of the rain attenuation, the main parameter used is the rain rate R, which is expressed in https://www.w3.org/1998/Math/MathML"> m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The rain rate can be described as the thickness of the precipitation layer, which felled down over the time period of one hour in the case when the precipitation is not evaporated, not soaked into the soil, and is not blown away by the wind. The evaluation of R-value is of crucial importance in the rain attenuation prediction. The rain attenuation depends on the meteorological conditions in the considered place. Consider that the maximum rain rate is https://www.w3.org/1998/Math/MathML"> 20 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with a probability of https://www.w3.org/1998/Math/MathML"> 99.99 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . If the rain attenuation for this rain rate is compensated by adding sufficient margin to the link estimation, there will be a https://www.w3.org/1998/Math/MathML"> 99.99 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> probability that the signal will be received with the specified performance. Thus there is a probability of https://www.w3.org/1998/Math/MathML"> 0.01 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where the anticipated attenuation will be exceeded. The translation is that there is a possibility of unavailability for 53 minutes over the entire year, assuming that the year has 8766 hours. 9. 3.1 Integration Time As mentioned above, the R-values are expressed in https://www.w3.org/1998/Math/MathML"> m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Time intervals between the readings of rainfall amount in many cases are unrealistic. The period of time between the readings of the rainfall amount values is called integration time τ and it is a very important parameter, because it can significantly change the R-value. High R-values are hidden when τ is long. Consider an example where the duration of the rain was 30 minutes. The total amount of the precipitation was https://www.w3.org/1998/Math/MathML"> 20 m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . It did not rain during remaining 30 minutes of the hour neither during the remaining 2,5 hours for the interval of 3 hours. Thereby, if we count the average R-value for that hour it will be https://www.w3.org/1998/Math/MathML"> 20 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . If we count the average R for the measuring duration of 3 hours, it will be 6,6 https://www.w3.org/1998/Math/MathML"> m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . But if we count R for every minute of that hour, we will find that https://www.w3.org/1998/Math/MathML"> R = 40 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , because in every of those 30 rainy minutes the amount of the precipitation was https://www.w3.org/1998/Math/MathML"> 0,66 m m / m i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . That is why the average R-values are unreliable. 10. 3.2 The "one-minute" rain rate Almost all rain attenuation methods require "oneminute" rain rate value. The "one-minute" rain rate value R is expressed in https://www.w3.org/1998/Math/MathML"> m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This value can be defined as the R-value for https://www.w3.org/1998/Math/MathML"> 0.01 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of time of the year, obtained using the rainfall amount value, which was measured in https://www.w3.org/1998/Math/MathML"> τ = 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> min and multiplied by https://www.w3.org/1998/Math/MathML"> 60 [ 10 ] , [ 11 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . However, in our case, 12-hourly instances data are used. There are various models for conversion of https://www.w3.org/1998/Math/MathML"> R ( τ - m i n ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> into R (1-min). [5], [6], [9]. One of such conversion models https://www.w3.org/1998/Math/MathML"> [ 14 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is presented in the following equation https://www.w3.org/1998/Math/MathML"> R 1 m i n = R τ min d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> d = 0.987 τ 0.061 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where https://www.w3.org/1998/Math/MathML"> R τ min https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is rain rate value measured in τ minutes https://www.w3.org/1998/Math/MathML"> ( τ ≥ 1 m i n ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> R 1 m i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the "one-minute" rain rate value. However, the results presented in this study are referred to the precipitation duration in minutes and then the result is divided by 60 . It is valuable to be reported that both results - method used and model of equations 6 and 7 -coincide with each other at low R-values but at high R-values there is an enormous deviation upwards with the worst result at the highest R-value which is duplicated. Figure 2. Skyros Island in the Northwest Aegean Archipelagos On the other hand, the main advantage of the "Worst-month" model which was proposed by ITUR [12] is that only the worst-month statistics must be collected, although it is appropriate in cases when the required reliability of the radio system is other than https://www.w3.org/1998/Math/MathML"> 99.99 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This month is not necessarily the same month in different year. The fraction of time when the threshold value of rain rate (so, and rain attenuation value) was exceeded is identical to probability that the threshold value of rain rate would be exceeded [15], [19]. 11. DATA ANALYSIS Our survey is focused on those measurements referred as Northwest Aegean Archipelagos, namely, Skyros Island as well as in Naxos Island which is approximately 110 nautical miles south. The differences in monthly, seasonally and daily amounts of rainfall are observed in Skyros island of Hellas (for every synoptic 3 or 12 -hour interval). Figure 3. Rain rate and relative refractive indexes forperiod January 2010 - December 2013 for Skyros Island. The precipitation amount as a meteorological index on Skyros has a maximum value of https://www.w3.org/1998/Math/MathML"> 74 m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for the period January 2010 to December 2013 . This value appeared in May 2012 for 55 minutes, giving a R-value of https://www.w3.org/1998/Math/MathML"> 81 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The day following this storm, an R-value of https://www.w3.org/1998/Math/MathML"> 43 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ( https://www.w3.org/1998/Math/MathML"> 36 m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for 50 minutes) was observed. The next maximum values for precipitation height appeared in June https://www.w3.org/1998/Math/MathML"> 2011 ( 64 m m ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for 1 hour and 20 minutes and in February 2012(53 mm ) for 6 hours, giving R-values at https://www.w3.org/1998/Math/MathML"> 48 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 8,8 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> respectively. Figure 4. Rain rate and refractivity values for the period January 2010 - December 2013 for Naxos Island. Regarding maximum R-values as presented in Table 4 , the next maximum appeared in December https://www.w3.org/1998/Math/MathML"> 2011 ( 24,7 m m / h ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with a https://www.w3.org/1998/Math/MathML"> 45 m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> rain height within 1 hour and https://www.w3.org/1998/Math/MathML"> 49 m i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , giving https://www.w3.org/1998/Math/MathML"> R = 25 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . R-values in between https://www.w3.org/1998/Math/MathML"> 10 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 24 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> observed only for the https://www.w3.org/1998/Math/MathML"> 0,1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per year ( 34 hours total) having an average precipitation height at https://www.w3.org/1998/Math/MathML"> 18 m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and a maximum at 48 mm. All other values are bellow https://www.w3.org/1998/Math/MathML"> 10 m m / h ( 1520 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hours in 4 years with an average at https://www.w3.org/1998/Math/MathML"> 4,9 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Following observed parameters values are presented for precipitation time interval ( τ ), precipitation height (h), pressure (P), dry temperature https://www.w3.org/1998/Math/MathML"> ( θ ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , relative humidity https://www.w3.org/1998/Math/MathML"> ( H ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , refractivity (N) and Rain-Rate ® at a specific parameter at its minimum (Table 2) and maximum value (Table 3 ) respectively. Table 2. Observed parameters values at a specific parameter at its minimum value (in bold). τ H P θ H N R minutes mm mbars https://www.w3.org/1998/Math/MathML"> 0 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> % https://www.w3.org/1998/Math/MathML"> m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 80 3,4 981,6 11,4 81 318 3 0 0 1021,8 https://www.w3.org/1998/Math/MathML"> - 0,6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 65 310 0 10 0 1006,9 32,4 19 293 0 0 0 1006 27,4 19 288 0 Table 3. Observed parameters values at a specific parameter at its maximum value (in bold). τ H P θ H N R minutes mm mbars https://www.w3.org/1998/Math/MathML"> 0 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> % https://www.w3.org/1998/Math/MathML"> m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 720 20,8 1016,9 20.8 88 336 2 0 0 1035 2,4 58 212 0 0 0 1000,9 35,2 31 321 0 0 0 1020,7 22 100 380 0 0 0 1013,3 29 78 388 0 55 74 1009,9 15,4 88 341 81 Table 4. Observed parameters values for rain-rate ®, relative humidity https://www.w3.org/1998/Math/MathML"> ( H ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , relative refractive index (n) and water vapor density ( ρ ) for a specific maximum R-value per month for 4 years. 12. REFRACTIVITY Another parameter to consider is the relative refractive index of the atmosphere given in equation 3 , which affects the curvature of the electromagnetic wave path and graces the fading phenomenon. For example, the anomalous electromagnetic wave propagation can cause disturbances to radar work, because variation of the refractive index of the atmosphere can induce loss of radar coverage. Accurate prediction of losses due to these factors can ensure a reliability of the telecommunication system, decrease the equipment cost and protect people. 13. 5.1 Refractive Index The relative refractive index, n, for the troposphere, is computed by [20] https://www.w3.org/1998/Math/MathML"> n = 1 + N ⋅ 10 - 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where N is the radio refractivity expressed by: https://www.w3.org/1998/Math/MathML"> N = N diy + N wet = 77,6 ⋅ P T + 3,732 ⋅ 10 5 ⋅ e T 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with P being the atmospheric pressure (in mbars), e the water vapour pressure (in mbars), and T the absolute temperature (in https://www.w3.org/1998/Math/MathML"> 0 K https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). This expression may be used for all radio frequencies. The relationship between water vapour pressure e and relative humidity is given by: https://www.w3.org/1998/Math/MathML"> e = H ⋅ e s 100 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where https://www.w3.org/1998/Math/MathML"> e s = EF ⋅ a ⋅ e x p ⁡ b - t d ⋅ t t + c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where https://www.w3.org/1998/Math/MathML"> a = 6.1121 m b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is the vapour pressure at the triple point and it has the same unites with es and https://www.w3.org/1998/Math/MathML"> E F = 1 + 10 - 4 ⋅ 7,2 + P ⋅ 0,0032 + 5,9 ⋅ 10 - 7 ⋅ t 2 ( 12 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where t is the temperature (in https://www.w3.org/1998/Math/MathML"> ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ), P is the pressure (in mbars), H is the relative humidity (in % ) es is the saturation vapour pressure (in mbars) at the temperature t (in https://www.w3.org/1998/Math/MathML"> ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) and the coefficients b,c and d for water for the measured temperature, are: https://www.w3.org/1998/Math/MathML"> b = 18.678 , c = 257.14 , d = 234.5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Vapour pressure e in mbars is obtained from the water vapour density ρ (in https://www.w3.org/1998/Math/MathML"> g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) using the equation: https://www.w3.org/1998/Math/MathML"> e = ρ ⋅ T 216,7 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where ρ is given in https://www.w3.org/1998/Math/MathML"> g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Skyros annual averages for the period 2010 to 2013 are https://www.w3.org/1998/Math/MathML"> N dry = 272 , E F water = 1,001 , e s = 20,3 , e = 13,02 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , https://www.w3.org/1998/Math/MathML"> N wet = 57,07 , N = 328,95 , n = 1,0003 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> ρ = 9,67 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> while Naxos averages which is located south from Skyros for the same period, are https://www.w3.org/1998/Math/MathML"> θ = 18 , 8 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> dry temperature, https://www.w3.org/1998/Math/MathML"> P = 1013,77 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mbars, https://www.w3.org/1998/Math/MathML"> H = 68,44 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> relative humidity, https://www.w3.org/1998/Math/MathML"> N = 336.18 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> ρ = 11,3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . It is noticeable that our statistics based at 12 -hour measurements 6:00 and 18:00, and this for the following reason: During the 12 -hour measurements, the station, recorded summed with the last 3 hour and all measurements were preceded during that 12 hour and were given separately in each 3 -hour observation. Note that the maximum value R, appeared in Naxos, on 5 th of November 2013 at 06:00 UTC and this value is https://www.w3.org/1998/Math/MathML"> 55,8 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , much smaller than this appeared in Skyros https://www.w3.org/1998/Math/MathML"> ( 81 m m / h ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . (a) (b) 2012 Night (d) https://www.w3.org/1998/Math/MathML"> ◻ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Figure 5. Rain Rate and Refractivity values for 2 years during day and night. 14. DISCUSSION The main models for calculation of electromagnetic wave attenuation due to atmospheric humidity and heavy precipitation phenomena, were revised. In Northwest Aegean Sea, Hellas, when the reliability of the radio system of https://www.w3.org/1998/Math/MathML"> 99,99 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is required, https://www.w3.org/1998/Math/MathML"> R ( 1 m i n ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> value equals to https://www.w3.org/1998/Math/MathML"> 81 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The attenuation of horizontally polarized electromagnetic waves is greater than the attenuation of vertically polarized electromagnetic waves. The dependency of the average specific electromagnetic wave attenuation due to rain on the operating frequency was determined. Figure 6. Hourly paremeters presentation on a rainy day with storms in May 2012 Figure 7. Hourly paremeters presentation on a drizzle day at the end of January 2011 The variations of the atmospheric humidity, temperature and pressure cause the fluctuations of the atmospheric refractive index. In Skyros, the atmosphere refractivity fluctuates between 288 and 388 for nights. This interval is shortening by https://www.w3.org/1998/Math/MathML"> 14 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for day periods. In heavy precipitation phenomena ( https://www.w3.org/1998/Math/MathML"> R > 10 m m / h ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> refractivity values are between 317 and 363 with https://www.w3.org/1998/Math/MathML"> N = 340 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at the maximum R-value. There have been observed 4 cases with very strong precipitation phenomena (R-values at 24,25,48 and https://www.w3.org/1998/Math/MathML"> 81 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for τ-values 50,109,80 and 55 minutes respectively). For these cases the initial interval for refractivity is shortening by https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 66 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> respectively for days and nights, having a minimum of 329. Except the fact values of refractivity are increased at nights as shown in Figures 5 , the same phenomenon exists for summer periods as it is observed in diagrams in Figure 5 . The explanation of this phenomenon is based on the fact that refractivity is inversely proportional to the temperature. Moreover, as it is shown in Figure 6, in strong precipitation phenomena, the temperature decreases and the relative humidity increases. The relative refractive index will be increased as it is proportional to the water vapor pressure (which in turn is proportional to the relative humidity) and inversely proportional to temperature. The same phenomenon is ob-served when the precipitation has very small rain-rates although the temperature, pressure relative humidity changes - and consequently refractivity and relative refractive index changes - occur a couple of hours later as it is presented in the diagram of Figure 7. Figure 8. Measurements in moderate precipitation phenomena showed a power loss of about 10 to https://www.w3.org/1998/Math/MathML"> 12 d B m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 2,4 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Measurements performed in a rainy day, for 40 minutes, with a wireless system at https://www.w3.org/1998/Math/MathML"> 2,4 G H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with minimum connection requirements approximately at https://www.w3.org/1998/Math/MathML"> - 80 d B m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The first measurement was performed without rain, at free space and the signal's power was varied from https://www.w3.org/1998/Math/MathML"> - 60 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> - 53 d B m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . With the use of a directional antenna the receiving power was between https://www.w3.org/1998/Math/MathML"> - 37 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> - 29 d B m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In the case of rain with R-value at https://www.w3.org/1998/Math/MathML"> 12 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the signal's power varied in between https://www.w3.org/1998/Math/MathML"> - 71 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> - 64 d B m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This 10 to https://www.w3.org/1998/Math/MathML"> 12 d B m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> attenuation was expected due to the path loss equation (4), [21]. and measurements are in accordance with theoretical results. 15. CONCLUSION The EM wave propagation characteristics depend on atmospheric refractivity. Nevertheless, atmospheric refractivity varies in time and space randomly. Therefore the statistics of atmospheric refractivity and related propagation effects are of main interest. This work investigated the major differences between radio refractivity changes for Northwest Aegean Archipelagos. Radio refractivity values were calculated from measured meteorological parameters (relative humidity, temperature and pressure) during a recent period of 4 years. The results showed that radio refractivity fluctuates between 288 and 388 but in strong precipitation phenomena where https://www.w3.org/1998/Math/MathML"> R ≥ 24 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> it fluctuates in between 326 to 363 (N-units). The rainfall rate exceeded for a probability of https://www.w3.org/1998/Math/MathML"> 0,01 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the average year and the location https://www.w3.org/1998/Math/MathML"> ( 24,32 ∘ E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , https://www.w3.org/1998/Math/MathML"> 38,50 ∘ N ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is https://www.w3.org/1998/Math/MathML"> 48 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and it is in accordance with previous published studies and ITU recommendations [22], [23]. Rainfall events with rain rates of https://www.w3.org/1998/Math/MathML"> 81,48,25 m m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> were observed in Skyros. The durations of these precipitations were 55 minutes, 80 minutes and 109 minutes respectively. The percentages of the time were 0.01 https://www.w3.org/1998/Math/MathML"> % , 0.015 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 0,02 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> respectively. Incorporating data on extreme weather events like heavy precipitation impacts, into GIS maps would be of tactical advantage for military operations [24]. More ore measurements have to be performed for various conditions of precipitation. Moreover, the analysis of rainfall data of the longer period (of several decades) and several points must be carried out to determine the parameters involved in rain attenuation prediction. 16. ACKNOWLEGMENTS Authors would like to acknowledge the contribution of Hellenic National Meteorological Service, Division of Climatology-Applications for providing meteorological data used in this study as well as the contribution of Dr. Th. Charantonis and Mr. Ch. Petropoulos for their valuable advice. Also, they would like to thank Mr. Konstantinos Alvertos, MSc candidate, for his contribution in experimental results, performing signal's power measurements. Last but not least, authors would like to acknowledge the contribution of Commodore (ENG) E. Stelioudakis and generally the Hellenic Navy for supporting this research. 17. REFERENCES [1] W.-Y. Chang, T.-C, C. Wang, P.-L. Lin, The Characteristics of Raindrop Size Distribution and Drop Shape Relation in Typhoon Systems from 2D-Video Disdrometer and NCU C-Band Polarimetric Radar, Joumal of Atmospheric and Oceanic Technology, vol. 26, 2009 [2] E. Villermaux, B. Bossa, Single-drop fragmentation determines size distribution of raindrops, Nature Physics, 2009 [3] J.S. Marshall, W.M. Palmer, The distribution of raindrops with size, Joumal of Meteorology, 5,1948 . [4] R.A. Nelson, Rain How it Affects the Communications Link, Applied Technology Institute, 2000 [5] Y. Karasawa, T. Matsudo, One-minute rain rate distributions in Japan derived from A Me DAS one-hour rain rate data, IEEE Transactions on Geoscience and Remote Sensing, 1991 [6] O. N. Okoro, G. A. Agbo, J. E. Ekpe and T. N. Obiekezie, Comparison of hourly variations of radio refractivity for quiet and disturbed days during dry and rainy seasons at Minna, International Journal of Basic and Applied Sciences, vol. 2, 2013 [7] Recommendation ITU-R P.1815-1, 2009, Differential rain attenuation. [8] M. Tamošiūnaitẻ, S. Tamošiūnas V. Daukšas M. Tamošiūniene M. Žilinskas, Prediction of Electromagnetic Waves Attenuation due to Rain in the Localities of Lithuania, Electronics and Electrical Engeneering, No. 9, 2010 [9] S. Tamošiunasa, M. Tamošiunien, M. Žilinskasa, Calculation of Electromagnetic Wave attenuation due to rain using Rainfall Data of Long and Short Duration, Lithuanian Journal of Physics, Vol.47, No. 2, 2007. https://www.w3.org/1998/Math/MathML"> [ 10 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> P. A. Owolawi, Rainfall Rate Probability Density Evaluation and Mapping for the Estimation of Rain Attenuation in South Africa and Surrounding Islands, Progress In Electromagnetics Research, Vol. 112,2011 [11] J. M. Gomez, Satellite Broadcast Systems Engineering, Artech House, 2002 [12] Recommendation ITU-R P.838-3, Specific attenuation model for rain for use in prediction methods, 2005 [13] R. L. Freeman, Radio systems design for telecommunication, Wiley, 2007 [14] F. Moupfouma, L. Martin, Modelling of the rainfall rate cumulative distribution for the design of satellite and terrestrial communication systems, International Journal of Satellite Communications and Networking, v. 13,1995 15] M. Tamošiūnaitē, M.Žilinskas, M. Tamošiūniené, S. Tamošiūnas, Atmospheric Attenuation due to Humidity, Elecromagnetic Waves, Edited by V. Zhurbenko, 2011 [16] Recommendation ITU-R P.676-10, Attenuation by atmospheric gases, 2013 [17] R. Uijlenhoet, Raindrop size distributions and radar reflectivity-rain rate relationships for radar hydrology, Hydrology and Earth System Sciences, vol. 5, 2001. [18] J. Bosy W. Rohm J. Sierny J. Kaplon, GNSS Meteorology, International Joumal on Marine Navigation and Safety of Sea Transportation, Vol. 5, 2011. [19] R. Crane, Electromagnetic Wave Propagation through Rain, Wiley, 1996 [20] Recommendation ITU-R P.453-10, The Radio refractive index: its formula and refractivity data, 2012 [21] E.A. Karagianni, A.P. Mitropoulos, A.G. KavousanosKavousanakis, J.A. Koukos and M.E. Fafalios, Atmospheric Effects on EM Propagation and Weather Effects on the Performance of a Dual Band Antenna for WLAN Communications, Nausivios Chora, Volume 5 , 2015 , in press. [22] A. D. Papatsoris, K. Polimeris, I. Sklari, A. A. Lazou, Rainfall Characteristics for Radiowave Propagation Studies in Greece, IEEE Antennas and Propagation Society International Symposium, 2008. [23] Recommendation ITU-R P.837-6, Characteristics of precipitation for propagation modeling, 2012 . [24] J. W. Weatherly and D. R. Hill, The Impact of Climate and Extreme Weather Events on Military Operations, ADA432260, 2004 Concepts of the GMDSS Modernization K. Korcz Gdynia Maritime University, Gdynia, Poland Abstract The current status of the Global Maritime Distress and Safety System (GMDSS) has been described. On the base of a current status of the GMDSS, the different concepts of the GMDSS modernization has been presented. The future of the maritime communication has been discussed as well. 18. INTRODUCTION The Maritime Safety Committee (MSC) at its https://www.w3.org/1998/Math/MathML"> 81 s t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> session, in 2006 , decided to include, in the work programmes of the Safety of Navigation (NAV) and Radiocommunications and Search and Rescue (COMSAR) Sub-Committees, a high priority item on "Development of an e-navigation strategy". It needs to be noted that the development of enavigation is an ongoing process and that the "Development of an e-navigation strategy implementation plan", as a next step of the project, was included in the work programmes of the COMSAR, NAV and Standards of Training and Watchkeeping (STW) Sub-Committees by MSC 85 , in 2008. Without a doubt, one of the fundamental elements of e-navigation will be a data communication network based on the maritime radiocommunication infrastructure. Taking into account the above, in 2009 at MSC 86, the Committee agreed to include in the COMSAR Sub-Committee work programme, a sub-item on "Scoping exercise to establish the need for a review of the elements and procedures of the GMDSS" under the work programme item on "Global Maritime Distress and Safety Systems https://www.w3.org/1998/Math/MathML"> ( G M D S S ) ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> In the aftermath of this work in 2012 MSC 90 agreed to include in agenda of the COMSAR, NAV and STW Sub-Committees a high priority item on "Review and modernization of the Global Maritime Distress and Safety System (GMDSS)", with a target completion year of 2017 , assigning the COMSAR Sub-Committee as the coordinating organ. After the changes in the organization of the work of IMO subcommittees at the end of 2013 , the issue of "Review and modernization of the Global Maritime Distress and Safety System" is, like the issue of "Development of an e-navigation strategy implementation plan", the competence of the new Sub-Committee on Safety of Navigation, Communication and Search and Rescue (NCSR), resulting from connections of the NAV and COMSAR Sub-Committees. In this context, during the discussion on the modernization of the GMDSS there are the different approaches to carry it out. 19. GMDSS FUNDAMENTALS The original concept of the GMDSS is that search and rescue authorities ashore, as well as shipping in the immediate vicinity of the ship in distress, will be rapidly alerted to a distress incident so they can assist in a coordinated search and rescue operation with the minimum delay. The system also provides for urgency and safety communications and the promulgation of maritime safety information (MSI). 20. 2.1 Functional requirements The GMDSS lays down nine principal communications functions which all ships, while at sea, need to be able to perform (SOLAS, 2014): 1 transmitting ship-to-shore distress alerts by at least two separate and independent means, each using a different radiocommunication service; 2 receiving shore-to-ship distress alerts; 3 transmitting and receiving ship-to-ship distress alerts; 4 transmitting and receiving search and rescue coordinating communication; 5 transmitting and receiving on-scene communication; 6 transmitting and receiving signals for locating; 7 transmitting and receiving maritime safety information; 8 transmitting and receiving general radiocommuni-cation from shorebased radio systems or networks; 9 transmitting and receiving bridge-to-bridge communication. Distress alerting is the rapid and successful reporting of a distress incident to a unit which can provide or co-ordinate assistance. This would be a rescue co-ordination centre (RCC) or another ship in the vicinity. When an alert is received by an RCC, normally via a coast station or a land earth station, the RCC will relay the alert to SAR units and to ships in the vicinity of the distress incident. Search and rescue (SAR) co-ordinating communications are the communications necessary for the coordination of ships and aircraft participating in a search and rescue operation following a distress alert, and include communications between RCCs and any on-scene co-ordinator (OSC) in the area of the distress incident. On-scene communications are the communications between the ship in distress and assisting units relate to the provision of assistance to the ship or the rescue of survivors. Locating is the finding of a ship/aircraft in distress or its survival craft or survivors. Ships need to be provided with up-to-date navigational warnings and meteorological warnings and forecasts and other urgent maritime safety information (MSI). MSI is made available by Promulgation of MSI by the responsible administration means. General radiocommunications in the GMDSS are those communications between ship stations and shore-based communication networks which concern the management and operation of the ship and may have an impact on its safety. Bridge-to-bridge communications are inter-ship safety communications conducted from the position from which the ship is normally navigated. 21. 2.2 GMDSS Sea areas Radiocommunication services incorporated in the GMDSS system have individual limitations with respect to the geographical coverage and services provided. The range of communication equipment carried on board the ship is determined not by the size of the ship but by the area in which it operates. Four sea areas for communications within the GMDSS have been specified by the IMO. These areas are designated as follows (SOLAS, 2014): - Sea area A1 - an area within the radiotelephone coverage of at least one VHF coast station in which continuous DSC alerting is available. Sea area A2 - an area, excluding sea area A1, within the radiotelephone coverage of at least one MF coast station in which continuous DSC alerting is available. Sea area A3 - an area, excluding sea areas A1 and https://www.w3.org/1998/Math/MathML"> A 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , within the coverage of an Inmarsat geostationary satellite in which continuous alerting is available. Sea area A4 - an area outside sea areas A1, A2 and https://www.w3.org/1998/Math/MathML"> A 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (the polar regions north and south of https://www.w3.org/1998/Math/MathML"> 70 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> latitude, outside the Inmarsat satellite coverage area). 22. 2.3 Ship requirements In accordance with SOLAS Convention every ship shall be provided with radio installations capable of complying with the functional requirements throughout its intended voyage (see Sec. 2.1). The type of radio equipment required to be carried by a ship is determined by the sea areas through which a ship travels on its voyage (see Sec. 2.2). Every ship shall be provided with: 1 VHF radio installation capable of transmitting and receiving: DSC on the channel 70 ; radiotelephony on the channels 6,13 and 16 ; 2 Search and Rescue Locating Device (SRLD); 3 receiver capable of receiving international NAVTEX service broadcasts if the ship is engaged on voyages in any area in which an international NAVTEX service is provided; 4 radio facility for reception of maritime safety information (MSI) by the Inmarsat enhanced group calling (EGC) system if the ship is engaged on voyages in any area of Inmarsat coverage but in which an international NAVTEX service is not provided; however, ships engaged exclusively on voyages in areas where an HF direct-printing telegraphy maritime safety information service is provided and fitted with equipment capable of receiving such service, may be exempt from this requirement; 5 satellite emergency position-indicating radio beacon (EPIRB). In addition to the above requirements every ship engaged on voyages in sea area https://www.w3.org/1998/Math/MathML"> A 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or https://www.w3.org/1998/Math/MathML"> A 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> A 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or https://www.w3.org/1998/Math/MathML"> A 1 , A 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> A 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or https://www.w3.org/1998/Math/MathML"> A 1 , A 2 , A 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> A 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> shall be provided with anditional radio installation. 22.1. Order of priority of communications In accordance with Radio Regulations all stations in the maritime mobile service and the maritime mobile-satellite service shall be capable of offering four levels of priority in the following order (RR. 2012 ): 1 distress communications; 2 urgency communications; 3 safety communications; 4 other communications. The transmission of a distress call indicates that a mobile unit or person is threatened by grave and imminent danger and requires immediate assistance. The urgency call indicates that the calling station has a very urgent message to transmit concerning the safety of a mobile unit or a person (for example medical advice or medical assistance). The safety call indicates that the calling station has an important navigational or meteorological warning to transmit. The other communication means any communication beyond distress, urgency and safety communications, for example public correspondence (any telecommunication which the offices and stations must, by reason of their being at the disposal of the public, accept for transmission). 23. CURRENT STATUS OF THE GMDSS Since implementation of the GMDSS some changes both of technical and regulatory nature have occurred. One of the most important GMDSS changes has concerned the Inmarsat. In 1999 , Inmarsat became the first intergovernmental organization to be transformed into a private company. It caused that at present Inmarsat is recognised as a leader in global mobile satellite communication field. Inmarsat B, launched in 1993 , was first maritime fully digital service. Inmarsat C, introduced in 1994 , is one of the most flexible mobile satellite message communication systems. Inmarsat Fleet service provides both ocean-going and coastal vessels with comprehensive voice, fax and data communications. Fleet 77 (introduced in 2002) fully supports the GMDSS and includes advanced features such as emergency call prioritization, as stipulated by IMO Resolution A. 1001 (25). Fleet F77 also helps meet the requirements of the International Ship and Port Facility Security (ISPS) code, which enables the cost-effective transfer of electronic notices of arrival, crew lists, certificates and records. Because Fleet 77 is IP compatible, it supports an extensive range of commercially available off-the-shelf software, as well as specialized maritime and business applications. Fleet 77 also ensures costeffective communications by offering the choice of Mobile ISDN or MPDS channels at speeds of up to 128kbps. FleetBroadband is Inmarsat's next generation of maritime services delivered via the Inmarsat-4 satellites. It is commercially available since the second half of 2007 . Inmarsat had over 175,000 registered GMDSScapable mobile terminals at the end of October 2014 , of which more than 154,000 were Inmarsat C. It should be also noted that Inmarsat E service (Lband EPIRB) ceased to be supporting GMDSS in 2006 and Inmarsat A service - in 2007. Instead of the Inmarsat E service, the new Cospas-Sarsat Geostationary Search and Rescue System (GEOSAR) has been introduced by CospasSarsat as completion of the Low-altitude Earth Orbit System (LEOSAR). These two Cospas-Sarsat systems (GEOSAR and LEOSAR) create the complementary system assisting search and rescue operations (SAR operations). At the same time, the Cospas-Sarsat ceased satellite processing of https://www.w3.org/1998/Math/MathML"> 121.5 / 243 M H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> beacons on 1 February 2009. It is also worth to note that in 2010 AIS-Search and Rescue Transmitter (AIS-SART) was introduced. So, shipboard GMDSS installations include one or more Search and Rescue Locating Devices (SARLD). These devices may be either an AIS-SART or a SART (Search and Rescue Transponder). And at the end, as the result of the hard work of International Maritime Organization (IMO) and other bodies, two new systems have been introduced: Ship Security Alert System - SSAS (in 2004), Long-Range Identification and Tracking of ships - LRIT (in 2009). Although the SSAS and LRIT systems are not a part of the GMDSS, in the direct way they use its communication means. Besides the above-mentioned main changes the following should be noted as well (Korcz, 2013): the cessation of aural https://www.w3.org/1998/Math/MathML"> 2182 k H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> listening watch; the requirement for passenger ships to have aviation VHF; the non-introduction of VHF DSC EPIRBs despite their inclusion in SOLAS; the introduction of the SafetyNET service together with Inmarsat-C and mini-C terminals; the introduction of a range of non-SOLAS Inmarsat services; the closure of much of the worlds "public correspondence" radiotelephony, Morse, radiotelex and VHF coastal radio networks; the advent of https://www.w3.org/1998/Math/MathML"> 406 M H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> digital distress beacons, with or without GNSS; the development of the Galileo GNSS; the civil availability of Glonass GNSS; the development of Man Overboard devices using DSC and AIS; proposals for EPIRBs equipped with AIS; the major decline in the use of radio-telex at sea; - the introduction of HF e-mail data (non-SOLAS) services for routine communications; the increase in availability of terrestrial and satellite communications networks; the increase in the bandwidth supported by many communications platforms, both terrestrial and satellite; the further development of the internet, and associated communications software, including "social media", and mobile phone "apps"; the increased use of e-mail by crews, and for ship's business; the widespread take-up of data-intensive technology for ship's business (i.e. e-commerce, digital photography for cargo and ship-related business, maintenance, medical applications, stability calculations, cargo calculations, engineering analysis, numerous reporting requirements for customs, immigration, quarantine, etc.); increasing broadband wireless access along coastlines; the further use of non-GMDSS earth stations aboard vessels; increased satellite bandwidth available in C-band and Ku-band via geostationary satellites; greater access to radiocommunications equipment by crews outside the GMDSS installation (i.e. cellular phones, and broadband wireless); the massive deployment of cellular telephony and broadband wireless along populated coastlines; the advent of much cheaper and smaller radioelectronics equipment; radio-navigation equipment/computing equipment product choice increasing and more equipment is being combined, particularly in the non-SOLAS sector; the commencement of the non-GMDSS "505" Inmarsat service; the new Arctic NAVAREAs/METAREAs; the advent of new satellite providers seeking participation in the GMDSS; the increased availability of affordable nonSOLAS satellite providers; the advent of software-defined radio (SDR); the development of Voyage Data Recorders (VDR); the use of wireless local area networks aboard ships; the advent of short-range wireless device interconnectivity ( https://www.w3.org/1998/Math/MathML"> P C s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , etc.); the use of marine pilots carrying their own PC with a range of marine software products; the advent of AIS Application-Specific Messages; AIS-equipment aids to navigation, including virtual and synthetic AtoN; the advent of Integrated Bridge Systems. Taking into account the above changes, up to date equipment and systems used in the GMDSS is showed in Fig. 1 (Korcz, 2013). Used in Figure 1 devices and systems abbreviations mean (Fig. 1): MES - Mobile Earth Station; LES - Land Earth Station; Inmarsat - Satellite System; EPIRB - Emergency Position Indicating RadioBeacon; LUT - COSPAS/SARSAT Local User Terminal; DSC - Digital Selective Calling; NBDP - Narrow Band Direct Printing; RTF - Radiotelephony; GNSS - Global Navigation Satellite System - for support (for example GPS-Global Positioning System); SARLD - Search and Rescue Locating Device; NAVTEX System; RCC - Rescue Coordination Centre. SAR - Search and Rescue Service. At a regulatory level a modification of the GMDSS is coordinated by two international organizations: International Maritime Organization (IMO) and International Telecommunication Union (ITU). IMO modifications are mainly concerning the amendments to Chapter IV of the International Convention for the Safety of Life At Sea (SOLAS) and the proper IMO resolutions. From the Radiocommunication point of view, the most important modification was adoption by IMO of Resolution A.1001(25) dated 29.11.2007 on Criteria for the Provision of Mobile Satellite Communication Systems in the GMDSS and revision of Chapter IV of IMO SOLAS Convention extends the International Mobile Satellite Organization (IMSO) oversight to GMDSS Services provided by any satellite operator which fits criteria [Korcz, 2011]. ITU modifications are mainly concerning the amendments to Radio Regulations. Since 1999 , these amendments were adopted by six World Radiocommunication Conferences (WRCs), which are held every three to four years. These World Radiocommunication Conferences were held in 1995,1997,2000,2003,2007 and 2012 (Korcz, 2013). From the point of view of the GMDSS modernization, among many important outputs of the WRC-12, the two documents are very important: Resolution 359 (WRC-12) "Consideration of regulatory provisions for modernization of the Global Maritime Distress and Safety System and studies related to e-navigation" and Resolution 360 (WRC-12) "Consideration of regulatory provisions and spectrum allocations for enhanced Automatic Identification System technology applications and for enhanced maritime Radiocommunication". 24. GMDSS MODERNIZATION As a result of the work on "Scoping Exercise to establish the need for a review of the elements and procedures of the GMDSS", the Maritime Safety Committee (MSC) at its 90 session decided to include, in the work programme of the Radiocommunications and Search and Rescue (COMSAR) Sub-Committee, a high priority item on "Review and modernization of the Global Maritime Distress and Safety System (GMDSS)". This new work item is to review the GMDSS, and then to develop a modernization programme. The modernization programme would implement findings of the review, include more modern and efficient communications technologies in the GMDSS, and support the communications needs of the e-navigation. At the beginning of the GMDSS modernization process a lot of issues were considered but the most important considerations concern the fundamental issues presented in Sec. 2. 25. 4.1 Functional requirements In considering the nine functional requirements (see Sec. 2.1), the following over-arching issues is considered (NCSR, 2014): the possible need for inclusion of security-related communications in the GMDSS; and the possible need to develop a clearer definition of "General Communications". The Ship Security Alert System (SSAS) does not involve communication with other ships or with coast radio stations. Therefore, those communications are neither ship-to-ship nor ship-toshore communications. Communications are addressed to a designated competent authority. Therefore, security-related communications should not be a functional requirement of the GMDSS but chapter IV should include a requirement for ships to be capable of security related communications, and a definition of "security-related communications" is also required. A definition of "security-related communications" is proposed as follows (NCSR 1): "Security-related communications means communications associated with the update of security levels, security incidents or threast thereof and security-related information prior to the entry of a ship into a port." The existing definition in SOLAS regulation IV/2.1.5, defines general radio communications as "operational and public correspondence traffic, other than distress, urgency and safety messages conducted by radio". Coast radio stations (Government owned) which provided public correspondence facilities when the GMDSS was first designed have now all largely been closed down. However, facilities for public correspondence are still required. These communications are now being achieved using commercial services which are not normally associated with coast radio stations and the term public correspondence is no longer widely used. For the Modernized GMDSS it is therefore proposed to change the term Public correspondence to "Other communications" and include a new capability for Other communications but not as part of the GMDSS functional requirements. The definition of urgency and safety communications (Radio Regulations) includes the following communications: 1 navigational and meteorological warnings and urgent information; 2 ship-to-ship safety of navigation communications 3 ship reporting communications; 4 support communications for search and rescue operations; 5 other urgency and safety messages; and 6 communications relating to the navigation, movements and needs of ships and weather observation messages destined for an official meteorological service. Operational communications are now, therefore, covered under the definition of urgency and safety communications. It is proposed to redefine the term "General communications" by aligning it with the Radio Regulations. The new definition proposed is: "General communications means operational communications, other than distress conducted by radio". So, the new text of functional requirements for the Modernized GMDSS is proposed as follows: 1 performing the GMDSS functions as follows: transmitting ship-to-shore distress alerts by at least two separate and independent means, each using a different radiocommunication service; receiving shore-to-ship distress alert relays; transmitting and receiving ship-to-ship distress alerts; transmitting and receiving search and rescue coordinating communications; transmitting and receiving on-scene communications; transmitting and receiving signals for locating; transmitting and receiving safety-related information; receiving Maritime Safety Information (MSI); transmitting and receiving general communications; and transmitting and receiving bridge-to-bridge communications, 2 transmitting and receiving security-related communications, in accordance with the requirements of the International Ship and Port Facility Security Code; and 3 transmitting and receiving other communications to and from shore-based systems or networks. 25.1. GMDSS Sea areas Four sea areas have been defined according to the coverage of VHF, HF and MF Coast Radio Services and Inmarsat Services as given in Sec. 2.2. During the review it was noted that extensive use was made of VHF communications and, therefore, sea area A1 should be retained. Because of considerable use of MF voice communications, it was finally concluded that sea area A2 should be retained as a separate sea area as well. The definition of the boundary between sea area A3 and A4 is currently defined by Inmarsat coverage, but Inmarsat might not always be the only GMDSS satellite provider. In future, the Organization might recognize regional or global satellite systems to provide GMDSS services in an A3 sea area, each of them providing coverage different to the current A3 sea area. It was considered that HF should remain a requirement for sea area A4 and an option for sea area A3. Recognizing that other options for the definition of sea areas A3 and A4 could be developed, three different options for the definition of sea areas A3 and A4 were identified as follows: OPTION 1 Sea area https://www.w3.org/1998/Math/MathML"> A 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> means an area, excluding sea areas https://www.w3.org/1998/Math/MathML"> A 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and A2, within the coverage of a recognized mobile satellite communication service using geostationary satellites in which continuous alerting is available. Sea area https://www.w3.org/1998/Math/MathML"> A 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> means an area outside sea areas https://www.w3.org/1998/Math/MathML"> A 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , A2 and A3. Above Option is the most similar to the current definitions, except that the reference to Inmarsat has been deleted. Option 1 does not facilitate the introduction of non-geostationary satellite systems. The boundary between sea areas A 3 and A4 would depend upon the satellite system used and could be different for different ships. OPTION 2 Sea area https://www.w3.org/1998/Math/MathML"> A 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> means an area, excluding sea areas https://www.w3.org/1998/Math/MathML"> A 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> A 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , within the coverage of a recognized mobile satellite communication service in which continuous alerting is available between [70 or 76 ] degrees North and South. Sea area https://www.w3.org/1998/Math/MathML"> A 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - Sub means a sub-area within sea area A3, within the regional coverage of a recognized mobile satellite communication service in which continuous alerting is available. Sea area https://www.w3.org/1998/Math/MathML"> A 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> means an area outside sea areas https://www.w3.org/1998/Math/MathML"> A 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , A2 and A3. Sea area https://www.w3.org/1998/Math/MathML"> A 4 - R https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> means a sub-area within sea area A4, within the regional coverage of a recognized mobile satellite communication service in which continuous alerting is available. Above Option defines a clear boundary for the A3 sea area and, as such, might be helpful to an Administration in issuing safety radio certificates to ships. OPTION 3 Sea area https://www.w3.org/1998/Math/MathML"> A 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> means an area, excluding sea areas A1 and A2, within the coverage of a recognized mobile satellite communication service in which continuous alerting is available as may be defined by the Organization. Sea area https://www.w3.org/1998/Math/MathML"> A 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> means an area outside sea areas Al, A2 and A3. Above Option defines the sea area A3 as somewhere where satellite coverage is available. The boundary between sea areas A 3 and https://www.w3.org/1998/Math/MathML"> A 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> would depend upon the satellite system used and could be different for different ships. The safety radio certificate would require details of the geographical area in which the ship is permitted to sail. Availability of a global satellite system would result in not having a sea area A4 for ships that are certificated to use a global system. 25.2. Ship requirements In future, if other satellite service providers are recognized by the Organization, the safety radio certificates of the ship should be required to define the geographic area in which the ship is permitted to operate. The detail of the geographical areas covered by all the different satellite service providers will be given in the GMDSS Master Plan. Taking into account the changes of the functional requirements (see Sec. 4.1) and GMDSS Sea areas (see Sec. 4.2) changes in the basic equipment of ships will also have to be introduced (see Sec. 2.3). 25.3. Order of priority of communications The Radio Regulations provide the existing order of four levels of priority (see Sec. 2.4). The four priorities are needed for communications and operational use in general, including voice, maritime safety information, as well as other text and data messages. Priorities for text and data messages can be used to sort message displays in order of importance or the way in which they are displayed. However, two priorities are sufficient for controlling the radiocommunication link, for example by using pre-emption. It is concluded, therefore, that the four levels of priority should be retained, and applied to voice, text, and data messages and that there is no need to revise Radio Regulations. Automated systems should give priority to category distress. Automated systems should also give priority to categories urgency and safety (ahead of other communications category). 26. CONCLUSIONS Discussion on the modernization of the GMDSS (marine radiocommunication) is still in very early stage. The main problems to be solved at this stage of work concern, discussed in the article, the concepts of modernization of the GMDSS, connected with the appropriate changes in the SOLAS Convention. More than twenty years have passed since the time when the Global Maritime Distress and Safety System (GMDSS) became introduced. Planning for the GMDSS started more than thirty years ago, so some elements of it have been in place for many years. There have been numerous advances in the use of maritime radiocommunication to maritime safety, security and environmental protection during this period. But now there are some obsolete GMDSS equipment and systems or the ones that have seldom or never been used in practice. The GMDSS is a system of systems, which like a "bus" going along the road, and certain technologies get off the bus and certain new technologies get on board the bus. The idea that the GMDSS and related systems are static is rather incorrect. Reference to the section 3 proves that the GMDSS continues to be a dynamic system, whilst still supporting the essential functions of the GMDSS (Korcz, 2011). On the other hand there are a lot of the new digital and information technologies outside the GMDSS. In the Author's opinion, the future of the GMDSS is closely connected both with the development of the e-navigation project and the role of the radiocommunication in this process. It is envisaged that a data communication network will be one of the most important parts of the e-navigation strategy plan (Korcz, 2009). In order to realize efficient and effective process of data communication for e-navigation system, the existing radio communication equipment on board (GMDSS), as well as new radio communication systems should be recognized. Apart from the satellite systems, the GMDSS MF, HF and VHF equipment and systems (Fig. 1) should be also used as a way of data communication for the e-navigation system, provided that this equipment and systems will be technically improved by means of (Korcz, 2013): digitization of the analogue communication MF, HF and VHF channels; application of high-speed channel to GMDSS; utilization of SDR (Software Defined Radio) technology; adaptation of IP (Internet Protocol) technology to GMDSS; integration of user interface of GMDSS equipment; and any other proper technology for GMDSS improvement. Analyzing the existing communication systems for inclusion in the modernized GMDSS, there are the opinions that mobile internet services, mobile telephone services, Broadband wireless access (BWA), eg. Wimax/mesh networks wireless Local Area Networks and non-regulated Satellite Emergency Notification Devices (SENDs), although more and more used by the public, including nonSOLAS ships for alerting, are not the appropriate means and, therefore, should not form part of the international system. More consideration is needed to decide which systems, relying on older or inefficient technologies, might be considered for replacement by more modern systems. The following new equipment, systems and technologies, currently not included in GMDSS, might be included in the modernized GMDSS (COMSAR, 2013 and NCSR, 2014): AIS, including Satellite monitoring of AIS and additional AIS channels for identification but not alerting; HF e-mail and data systems; VHF data systems; Application Specific Messages over AIS or VHF data systems; NAVDAT. Modern satellite communication technologies; Additional GMDSS satellite service providers; Hand-held satellite telephones in survival craft; Hand-held VHF with DSC and GNSS for survival craft; Man Overboard Devices; and - AIS and GNSS-equipped EPIRBs. In considering the GMDSS modernization the following developments that are already under way should be taken into account as well: proposed FleetBroadband FB500 terminal for GMDSS; Inmarsat MSDS (Maritime Safety and Data Service) over BGAN FleetBroadband; proposed Cospas-Sarsat MEOSAR network (will be probably fully operational in 2018) and retirement of the Cospas-Sarsat LEOSAR network; new GNSS projects (eg. Galileo); introduction of new broadcasts to ships using systems in the 495-505 kHz band; and the following changes in the GMDSS which might be expected to occur in the near to mid-term: the provision of hand-held satellite telephones in survival craft; the provision of handheld VHF with DSC and GNSS for survival craft; all SOLAS EPIRBs to be fitted with GNSS; EPIRB-AIS; EPIRB-AIS to be used with/in voyage data recorders; MOB-AIS next generation AIS; development of an electronic equipment; using AIS in a new "ranging mode"; additional AIS channels for channel management and data transfer; the use of Channels 75 and 76 for enhanced detection via satellite; harmonized digital bands in VHF RR; the further evolution of Maritime Safety Information broadcast systems, taking into account the ongoing work in IHO and WMO; an eventual replacement of MF NAVTEX with a new higher data-rate system in the 495-505 https://www.w3.org/1998/Math/MathML"> k H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> band; a new channel plan for Appendix 17 HF bands to permit new digital emissions, whilst still allowing Morse and NBDP, and protection for GMDSS MSI; the introduction of an e-navigation communications suite independent of the GMDSS, but with interconnections with it. It should be also noted that Inmarsat Global Limited has informed of its intention to close the Inmarsat-B Service from 31 December 2016. During work on review and modernization of the GMDSS it is necessary first to identify real user needs and secondly to realize that the modernization of the maritime radiocommunication should not be driven only by technical requirements. In addition, it is necessary to ensure that man-machine-interface and the human element will be taken into account including the training of the personnel. The lessons learnt from the original development and operation of GMDSS should be taken into consideration in the modification of GMDSS as well. Furthermore, the continuous and open process is needed to ensure it remains modern and fully responsive to changes in requirements and evolutions of technology and it will meet the expected e-navigation requirements. In order to ensure it, a mechanism for continuous evolution of the GMDSS in a systematic way should be created as well. In this approach to development of the GMDSS it is very important that the integrity of GMDSS must not be jeopardized. It should be noted that in this context, for the process of the GMDSS modernization, regulatory decisions taken on the World Radiocommunication Conference being held in https://www.w3.org/1998/Math/MathML"> 2015 ( W R C - 15 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and in 2018 (WRC-18) will be of great importance. And finally it should be noted that a key to the success of the review and modernization process of the GMDSS is not only that the work is completed on time, but also that it has the flexibility to implement changes ahead of schedule. In this approach to development of maritime radiocommunication it is also essential that the integrity of the GMDSS must not be threatened. 27. REFERENCES International Maritime Organization (IMO), 2014. International Convention for the Safety of Life At Sea (SOLAS), London International Telecommunication Union (ITU). Radio Regulations (RR), Geneva 2012 Sub-Committee on Radiocommunications, Search and Rescue - COMSAR 17. 2013. Report to the MSC, International Maritime Organization (IMO), London Sub-Committee on Radiocommunications, Search and Rescue NCSR 1. 2014. Report to the MSC, Intermational Maritime Organization (IMO), London Korcz K. 2009. Some Radiocommunication aspects of eNavigation. 8th International Navigational Symposium on Marine Navigation and Safety of Sea Transportation, TRANS-NAV 2009, Gdynia Korcz K. 2011. Yesterday, today and tomorrow of the GMDSS. 9th International Navigational Symposium on Marine Navigation and Safety of Sea Transportation, TRANS-NAV 2011, Gdynia Korcz K., 2013. Modernization of the GMDSS, 10th International Symposium on Marine Navigation and Safety of Sea Transportation, TRANS-NAV 2013, Gdynia. Supporting Situation Awareness on the Bridge: Testing Route Exchange T. Porathe Norwegian University of Science and Technology, Norway A. Brodje & R. Weber Chalmers University of Technology, Sweden D. Camre & O. Borup Danish Maritime Authority, Denmark Abstract In a simulator study parts of the Sometimes people misunderstand each other's intentions. That happens at sea as well as in all walks of life. To prevent accidents at sea the International Maritime Organization (IMO) has established the International Regulations for Preventing Collisions at Sea (COLREGS). They are supposed to unambiguously determine which ship is to stand on and which is to give way in a collision avoidance situation. However misunderstandings occur, a collision in the English Channel in 1979 can serve as an example: The Liberian bulk carrier Artadi was proceeding NE in the Traffic Separation Scheme (TSS) in the Dover Strait in restricted visibility (see Figure 1). The French ferry St-Germain was approaching from the east. She was spotted in good time on the radar of the Artadi. Coming from starboard, St-Germain was the stand-on ship according to rule 15 of the COLREGS, however, according to rule 19 both ships should give way in this case of restricted visibility. The pilot and master of the Artadi expected St-Germain to keep speed and course and started to make a starboard turn to give way. However, on-board the St-Germain the intention was not at all to cross the traffic separation scheme diagonally in front of Artadi, but instead to turn port and follow outside the boarder of the NE going traffic lane until the traffic cleared and she could make the crossing at a right angle (according to rule https://www.w3.org/1998/Math/MathML"> 10 c ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In the subsequent collision two persons were killed (Kwik, 1984; Office of the Commissioner for Marine Affairs, 1979). Figure 1. Misunderstanding intentions: The collision of French train ferry St-Germain with Liberian bulk carrier Artadi in the English Channel, 1979. 27.1. ACCSEAS One of the surprising findings in the recently concluded EU project ACCSEAS (Accessibility for Shipping, Efficiency Advantages and Sustainability) was how the development of off-shore wind turbines would restrict shipping in the southern part of the North Sea in the future. Looking at the plans for future wind farms the project came up with the map in Figure 2 (ACCSEAS, 2013). The polygons are planned wind mill parks in some stage of concession. We here see a clear trend: the shipping industry must in the future be prepared to share ocean space with a lot of new actors, not only wind energy, but different sorts of off-shore farming as well. Figure 2. The south part of the North Sea. Number of ship predictions for 2020+ (2012 numbers in parenthesis). The polygons are planned areas for wind turbines. The fussy lines are 2012 traffic density plot summarized in the solid lines, darker polygons areas are TSS separation zones. (ACCSEAS, 2013) The problems of navigation caused by one of these new installations might be exemplified with the newly constructed Thornton Bank wind mill park outside Zeebrugge on the Belgian coast (see Figure 3). Figure 3. The newly constructed Thornton Bank wind mill park has forced the P&O ferry to change its route causing possible risks of misunderstandings. The P&O ferry between Zeebrugge and Hull in the U.K. needed to change its route due to the newly constructed park. While the old track (dashed) gave some indications of the ferry's intentions, the new track (filled line) headed straight towards the main English Channel TSS at a right angle as if the intentions were to cross straight over. This TSS is the most trafficked route in the world with 133000 passing's in 2012 (ACCSEAS, 2013). Ships coming up the TSS towards the North Sea could potentially misunderstand the intentions of the big ferry approaching form starboard. And as more wind mill parks appear we are getting closer to the street-like situation we are used to in road traffic in cities. Only, cars have direction indicators which are something we do not have on ships. The only indication of the intent of the approach P&O ferry would be to see the destination through the AIS static message and try and deduce the intentions from there. That is why one of the suggested solutions from the ACCSEAS project is a service aimed at showing ships intentions to other vessels in the vicinity. 27.2. Tactical and strategic route exchange Situation awareness is a fundamental property for humans driving any kind of vehicle. Endsley defined it in 1988 as "'"the perception of elements in the environment within a volume of time and space, the comprehension of their meaning, and the projection of their status in the near future." Not only knowing what is going on, but also being able to predict what will happen in the future is crucial for navigation ships with large inertia. With regards to the future whereabouts we will use the following taxonomy when talking about ships future positions (see Figure 4). Figure 4. Taxonomy of route exchange based on how long in advance the service aims to predict vessels future positions. The levels are explained in the text. 27.3. Predictors On the very close scale ships use predictors. Predictors may be able to look some 3 to 15 minutes into the future and are typically very reliable on short time ranges. They simply extrapolate present speed and heading a number of minutes into the future. This type of simple prediction is typically used by AIS and ARPA radar where targets show course and speed by the direction and length of a vector, sometimes augmented by symbols for rate of turn (ROT) prediction extrapolating ships present turn speed when conducting a turn. Because ships are heavy and cannot change course or speed very rapidly, predictors are reliable up to some 3 minutes. Longer predictions rely on the ships not making any course speed changes. The predictor is often used to investigate possible close quarter situations by changing the time setting for own and other vessels course speed vector on the ARPA or the ECDIS onboard. 27.4. Strategic route exchange In the other end of the scale we have long term strategic route exchange which is part of the Ship Traffic Management (STM) concept which is being investigated by the MONALISA project. Every ship is mandated to make a berth-to-berth voyage plan before leaving port. In the old days the voyage plan was a pencil line on the paper chart; today the voyage plan resides in the electronic chart system, the ECDIS. The main objectives for sharing voyage plans are safety and efficiency. By coordinating voyage plans collisions might possibly be avoided by awareness of upcoming congestions. By coordinating voyage plans with availability of port facilities, fuel and emissions might be saved and efficiency in the transportation chain increased. Although it is easy to find the present position and destination of any ship though AIS data in the Internet, the voyage plan is considered to be of business interest and not to be shared with anybody. Strategic route exchange therefore involves a coordination center doing the route coordination. 28. 1.5 Tactical route exchange On a level between the short range predictors and ships entire voyage plans, we have the Intended routes. The idea here is to transmit a number of waypoints ahead of the ships present position with the AIS message (or some future system) and so show any ships intentions some 60-90 minutes ahead. Presently we have tested sending out 8 waypoints. The shown intentions will then differ in length depending on the density of waypoints The intended route should be integrated in the ECDIS and shown on demand not to clutter the screen with all ships intended routes. 28.1. Collision avoidance zone In earlier tests with intended routes users intuitively started using the intended routes to negotiate behavior for collision avoidance (see Porathe, Lutzhoft, & Praetorius, 2013) it became clear that there needed to be a psychological cut-off distance where navigators stop using computer systems to negotiate evasive maneuvers and start using basic COLREGS based on visual observation and ARPA. The radius of that zone would be dependent on several factors like traffic density, vessel type, speed and weather. The range might typically be 6-10 miles. However, having said that, it was found in the earlier study that negotiating by clicking and dragging waypoints in the intended route might be a way of avoiding to enter into a close quarter situation. Provided it was done in good time. 29. METHOD Human (or User)-Centered Design is a design philosophy that aims to involves the user throughout the design process from early context enquiries on through prototype design and different level user tests (Norman, 1988). In research projects like the ACCSEAS new solutions are tested in very early phases of the development process with the goal to investigate professional acceptance of a new service. Mainly qualitative data is collected with methods like Usability testing. Usability is defined as "the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency, and satisfaction in a specified context of use." (ISO 9241-11) Also learnability and safety are important aspects to investigate. In this test users (ship officers and VTS operators) were asked to use the Intended route service during different port approach scenarios. The testes had a high level of ecological validity through the use of full mission bridge simulators and VTS simulators. During the test observers on the bridges and in the VTS filmed and asked questions to the participants who were encouraged to think aloud. After the scenarios a debriefing session was held. The participants were also asked to fill in a survey rating their professional acceptance of the Intended route service. 29.1. The e-Navigation Prototype Display To be able to test the Intended route service an ECDIS-like test platform had been developed by the Danish Maritime Authority: The EPD (E-navigation Prototype Display). The platform contained enough ECDIS features to be able to replace the ordinary ECDIS in the full mission bridge simulators used. An EPD Shore system had also been developed for use in the VTS center. All systems had the ability to exchange route information such as the Intended route service (but also Suggested routes from shore to ship and strategic route exchange as explained above). By right-clicking on an AIS target and selecting "Show intended route" in the EPD the intended route of the vessel was shown (if the vessel indeed had the Intended route service, which was not always the case as was though realistic). There was also a choice of "Show all ships intended routes". In Figure 5 the portrayal of the Intended route service is shown. Figure 5. This is how the own ships route (below) and two ships intended routes (top) was portrayed in the EPD. There was also a feature that allowed the navigator to query other ships intended routes based on the planned speed that had been entered into the voyage plan. By moving you cursor over the other ships intended route a CPA Guidance Line would appear connecting the cursor with the point on your own ships track where you would be when the other ship was on the position of the cursor (given planned route and speed was kept). The portrayal of this feature is shown in Figure 6 . Figure 6. The CPA Guidance Line connecting the point the cursor is at on another vessels intended track with the position the own vessel is calculated to be at the same time. The same feature is used for the CPA Alert feature. If the calculate CPA of any vessel transmitting Intended routes becomes less that a predefined distance, e.g. 0.5 mile, CPA Guidance Lines calculated for each minute becomes visible highlighted in yellow together with the risk vessels intended track and an audible alarm(see Figure 7). 30. 2.2 Simulator study The study took place during four days in the end of September 2014 at the Simulator Centre at the Department of Shipping and Marine Technology at Chalmers University of Technology in Sweden. Two Transas 5000 bridges and one VTS station were used, using parallel worlds so that the two ships could not see each other but interacted instead with target ships controlled by the simulator instructor station. The VTS could see both ships on different screens. Two other e-Navigation services (the Suggested route, and the NoGo area services) were also tested. These results are presented separately. Figure 7. The CPA Alert feature warning for a possible future close quarter situation. Note here the difference between ARPA CPA (based on present route and speed) and Route CPA based on the Intended route. 31. 2.3 Scenarios Five scenarios in the river and approach to the Humber Estuary were suggested by experts from ABP Humber. The area was chosen because high ship density and changing tidal situations. The area had also a VTS service. Own ship in all scenarios was a https://www.w3.org/1998/Math/MathML"> 180 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> long ro-pax ferry. An overview of the geographical limits of the 5 scenarios can be seen in in Figure 8. Figure 8. The image shows an overview of the five scenarios in the Humber River areas in eastern U.K. In the first scenario the ferry was bound for Hull approaching the Sea Reach TSS in northerly gale. In order to avoid heavy rolling with beam seas the vessel was to re-route using the Rosse Reach TSS. The second scenario involved a special transport (wind turbine propeller) with extensive width. Thus requiring an exclusion zone according to port regulations. Own vessel was re-routed by the VTS using the Sunk Dredged Channel (see Figure 9). The third scenario was traffic congestion outside Immingham Oil and BulkTerminals. Several large ships was maneuvering in the area and the ferry was re-routed by the VTS using the Foul Holme Channel. The fourth scenario was a contravention scenario in the TSS off Spurn Head. A deep draught vessel needed to use the inbound TSS and the ferry was asked to use "the southern part of the inbound TSS" when passing. Figure 9. Screen shot from the EPD during scenario 2: own ship in Sunk Dredged Channel outbound ship passing through the main channel. The final scenario involved a vessel leaving Anchorage A for Immingham with a strong south bound current. This situation has several times caused ships to hit the North New Sand N-cardinal light buoy. Most of the scenarios involved the VTS at Spurn Head sending out route suggestions (which is disseminated in a separate conference paper), but all scenarios involved several other ships. Thereby reflecting the Humber area being one of the busiest ports in the UK. The five scenarios took two days with familiarization, briefings and debriefings between all scenarios and the final discussion at the end. 31.1. Participants 11 professional British, Swedish and Danish bridge officers, harbor masters, pilots and VTS operators with experience from traffic in the Humber area were used for the test. All the participants were male from age 32 to 58 , with a mean age of 47 years. They all had a sea time ranging from 12 to 30 years, mean 22 years. Each bridge was manned with two bridge officers, which would be realistic considering that the situation was approach to port with restricted waters and heavy traffic. The Spurn Head simulated VTS was manned with two VTS operators from the actual VTS center. The VTS operators were available from the whole test except on the last day when a Gothenburg VTS operator took over the chair (after having worked together with the Humber operators the day before). 32. RESULTS The comments from the videos and discussions were analyzed and the results are below presented in four levels: conceptual, procedural, functional and HMI (Human-Machine Interface). Quotes are from the video recordings. 33. 3.1 Conceptual level All the participants agreed that this service was valuable. "I might not have said so three days ago, but now having used it: Yes, the concept is very good. Provided the data that is displayed is correct." (said by Humber pilot with 12 years' experience). On a question if someone in the group was against the concept, there were head shakes and silence. Several of the participants soon got used to the service where they could see ships intentions; one said "after having used the system for six hours I find it annoying not being able to see ships intentions." (He was referring to the fact that some of the target vessels did intentionally not send out Intended routes.) 33.1.1. Training Several participants talked about the importance of "correct data": that the voyage plan was updated and correct and from berth-to-berth. It is necessary that the bridge personal are trained and can handle the system. Generally today, the Humber participants explained, the tankers coming into river have very good passage plans because they are heavily vetted. The general cargo and bulk carries, however, generally tend to have a voyage plan that either stops at the pilot station, or - if it goes all the way to the berth - do so by a couple of haphazard waypoints. If the displayed data is not correct it could be a dangerous concept: you think you know where someone is going, but instead they are going a completely different route. E.g. there might be a change in the voyage plan and because the https://www.w3.org/1998/Math/MathML"> 2 nd https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> officer responsible for voyage planning is not on watch, the new intentions are not displayed. One of the pilots said: On a big ship like the P&O ferry they have the time and people to do the voyage plan prudently with the right speed on all legs, etc. But on a small coaster they will just click out the waypoints, they don't have the time or the people to do anything else. "So my concern is not so much the quality of the proposed system, much more so, the quality of the people onboard that must be able to use the system." 33.1.2. Cluttering Going into details, the participants felt that it is important that rather than displaying all ships Intended routes all the time (which would clutter the display) you can (as indeed was the case) "interrogate" the display for intentions of vessels of interest. 33.1.3. Turning off transmission intended routes A discussion took place of what to do if a ship for some reason had to deviate from its route. One suggestion from the developers was that there should be an easy (or maybe even automatic) way of turning off the transmission of the Intended route if the vessel for some reason deviated too far from its intended voyage plan. One of the pilots answered "Yes, having no data is better than having the wrong data." There was an agreement that it could be a good thing if the system stopped sending route intentions if the ship was some predefined distance from its intended route for a predefined amount of time. But for minor deviations from the intended route, like overtaking, or giving extra space in a meeting situation, no one in the group felt it was necessary to stop sending, or changing the intended route. It would be obvious why the deviation was made. There was also an agreement that the Intended route service should not be used as a collision avoidance tool in close quarters situations. 33.1.4. Use in approaches and open sea It was felt that the Intended route service was probably being more important in open seas than in port approaches like the Humber River, because there is already a risk mitigation service like pilot onboard and VTS that keeps an eye on things. But for ships coming to the pilot station it is good, but there are also uses on the river. Approaches to junction points is an example where the Intended route service can be very valuable, for example a small ship leaving the Baltic Sea destined for Rotterdam may equally well take a route via The Sound, the Great Belt or the Kiel Canal. Being able to see the intended route makes it possible for an overtaking ship to place itself on the proper side of the other ship. 33.1.5. Trust One of the participants said on a question if he would trust an Intended route, that he would trust it in the same way that he today trusts the AIS information. "I will not trust 100 percent, but it is helpful." 33.1.6. Planned speedvs. current speed There was a major discussion on whether planned speed or current speed should be used when calculating a ships future position. The Intended route service as it was implemented in the prototype system was using the planned ETA in all waypoints to calculate where own and other ships would be at a certain time. The planned speed was based on the notion that ships should be at their final destination precisely in the planned arrival time. However, one of the pilots commented that in reality ships will not be following their planned speed exactly why the ETAs in different waypoints (at least the closest ones) instead should reflect the actual, current, speed of a vessel. "You always want to go a little bit faster to make sure that you can make your ETA Rush to wait. You will burn a little bit more fuel, but it cost more to let the stevedores, the lorries, etcetera wait." 33.1.7. Pre-checked Alternative routes An interesting issue brought up was use of alternative routes. When you are doing you berth-toberth voyage plan you may make e.g. two alternative routes on either side of e.g. an island or a bank. Both of them will be checked for UKC etc. One of them would be the preferred one (visible as the Intended route) but the officer could easily change to the alternative route if the weather or traffic situation so demands 34. 3.2 Procedural level 34.1.8. Workload It was discussed if the Intended route service would increase workload compared with today to a point where you would need to have an extra person on bridge just to run the system. Observation during the test scenarios showed that the usability of the system was not optimal yet and the participants were given help when they did not know how to activate a feature. Several participants commented however that they would expect the handling of the service to be smooth once they mastered the system. The test scenarios took place close to port or in the approach and this is where you would normally be two persons on the bridge. In a deep sea passage there would be only one officer on the bridge, but then the situations would normally be a lot calmer. "The workload remains the same, but the system will increase the quality of decision making," was one comment. The Intended route service might lessen workload for the pilot as the rest of the bridge team can see the intentions and future whereabouts of other vessels. One of the pilots mentioned that he spent a lot of time explaining to the captain or watch officer what was the intentions of other ships in the area leaving berth or entering into the approach channel. One of the VTS operator said that, given the VTS had Traffic Organization Service (TOS) authority, the Intended route service would greatly increase the opportunity and possibility to organize the traffic. This would be of great value but would also increase the workload in the VTS. 35. 3.3 Functional level Normally you have your ECDIS off-centered with most of the space in front of your ship and very little space behind you. But sometimes you are overtaken by a much faster ship. If you use route CPA as a filter for turning on Intended routes automatically you might get too many intended routes visible cluttering the screen, but it would be nice if you could have a "guard zone" astern which would turn on Intended routes only from overtaking ships. It would probably be necessary to have a "harbor" and a "sea" mode with different route CPA filter settings. An issue could be that you are making an approach. You investigate the other vessels intended routes and you make a strategy for how you want to deal with upcoming meetings. Then one of the vessels changes his intended route. The chance is that you will not notice that. It might be useful with some form of highlighting of changed intentions. 36. 3.4 HMI level 36.1.9. Intuitive use The user friendliness of the system was discussed. It was pointed out that it was important that all watch officers onboard could use the system so that updates of Intended routes did not have to wait for that the responsible navigation officer (normally https://www.w3.org/1998/Math/MathML"> 2 nd https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mate) was on watch. "But I think if we were here for another week we would be a lot quicker and comfortable with it. It is not a difficult system to use. It is more a question of familiarity, rather than the system being complicated." 36.1.10. Cluttering During the first round of tests users commented on the HMI that it was difficult to distinguish intended routes from each other as they all had the same light green color, and also to know which track belonged to which ship (the label with ship information was only shown on mouse-over on the vessel AIS target triangle). Because we had the programmer present during the tests the interface was updated for the next set of trials starting the day after. In the new HMI an Intended track could be queried by pointing at it with the cursor. The track would then become highlighted in a darker green color, the vessels icon would become highlighted with a circle and the position on the intended track line where the cursor pointed would be connected to the own ship's position at the same time by a CPA Guidance Line (see Figure 6). These lines could be used to query another ships track about the closest point of approach (CPA). The second round of participants found theses new features useful and decluttered the interface somewhat. Overtaking another vessel on a similar route is still difficult because the intended route of the other vessel may be hidden by your own route. It was also mentioned that routes needed to be transparent so that they did not hide e.g. depth figures. "The green color of the intended routes makes them difficult to see; especially if you got more than one. Maybe you could use different colours; you need to be able to separate one vessel from another." The text and symbols are too small in the EPD. "When you get to our age you cannot see such small print" 37. 3.5 Survey The participants were asked to summarize their impressions about the service in a survey with three questions. Only 9 of the 11 participants answered the survey as 2 had to leave early. 1 What is your opinion about the tested Intended routes concept? All the 9 answering participants answered Good or Very good. Noone answered I don't know, Bad or Very Bad. 2 Do you think a similar Intended routes concept will become reality in the future? On this question all 9 participants answered Probably or Most probably. No one answered I don't know, Probably not or Most probably not. 3 What is your professional opinion about the system tested? On this question the participants were asked to rank their acceptance on a scale between 0 and 5 where 0 was "Totally unacceptable", 1 was "Not very acceptable", 2 was "Neither for, nor against", 3 was "Acceptable", 4 was "Very acceptable" and 5 was "Extremely acceptable". The mean acceptance score from the 9 answering participants was 3.7, somewhere between "Acceptable" and "Very acceptable". 38. DISCUSSION It is of course of outmost importance that "intended routes" are understood as just "intentions" and not as a deterministic future. This was discussed very much during the 4 day test, but the concept of intended routes (as indicated by the very name of the service) seemed to be fully understood by the participants. There was an agreement that there should be a function that allowed ships to stop sending Intended routes if they for some reason had to change their intentions and did not have time to change the voyage plan on the chart display, but for minor offsets, like overtaking another vessel, or giving extra room in a close quarter situation, they did not feel it was necessary to turn off the Intended route. What was going on would be obvious to everyone. The scenarios chosen were normal everyday situations and they were based on real scenarios that were either described to us by the Humber pilots and VTS operators on a previous focus group meeting held in Hull several months before. In one case (The number 4 scenario, contravention in the TSS) the scenario was based on a AIS video provided by the Spurn Head VTS. In no case did we see what we considered any dangerous behavior by the participants onboard or ashore. 38.1. Planned versus current speed The discussion on planned versus current speed was interesting. One major idea with route exchange on the STM level is to make a new energy and emission saving paradigm with slow steaming and just-intime-arrival replace the old wasteful full-speedahead, then anchor and wait paradigm. To make such a system work ships would be expected to follow their planned voyage plan exactly. This will be necessary in order to calculate safety feature using dynamic separation where no two ships would be allowed to set out on a voyage plan where they would be at the same place at the same time. So both from a fuel and emission saving, as well as a safety perspective, it would be essential that current and planned speed was the same. This is not the case today, where the present paradigm is "rush to wait", as was mentioned by one of the participants. Keeping a very exact speed down to a tenth of a knot, according to the voyage plan, would be difficult manually and would require a speed pilot. (Which like an autopilot automatically keeps the set speed.) The advanced speed pilots needed are today only used by some ferry lines, and are not common in the merchant fleet. A ships speed is also depending on being within a limited window of propeller revolutions and the speed resulting from the number of revolutions will depend on wind, sea state and depth. So while waiting for engines and speed pilots that will allow an exact voyage plan to kept, the use of current speed to calculate ETA in all waypoints except those designated as "critical" (e.g. final destination, arrival at a lock or passing a congested area where traffic management is essential) might be a solution. 39. 4.2 Alternative routes The alternative route suggestions brought up during the test is maybe more relevant to the strategic route planning of the MONALISA project than the tactical Intended route of the ACCSEAS, but never the less very interesting. If the Ship Traffic Coordination Centre suggested in MONALISA would be aware of both the preferred and the alternative routes, they could, if need be, use the Alternative as a new strategic route suggestion. That way the shipping companies would retain more control of the suggestions made by the STCC (which was mentioned as imperative by a cruise ship captain during another simulation in 2013). 40. 4.3 Workload It was unclear whether the Intended route service would increase or lessen the workload on the bridge. In the scenarios tested the situation was port approach with two officers on the bridge. At times one of them would be occupied handling the chart system. To a large extent this could be because they were not proficient with the system (and several also said that the system felt easy to learn given ample time to practice). The system lends itself to making intentions clear and could be used for meeting and overtaking situations, but the system must not be used for collision avoidance in close quarters situations. The user interface seemed to be intuitive and relatively easy to work with: A participant added a new WP and dragged it to starboard to indicate to a stand-on vessel from starboard that he had the intention to go astern of him. First time user, https://www.w3.org/1998/Math/MathML"> 50 s e c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 41. CONCLUSIONS The Intended route service was considered a valuable concept. Intended routes should be displayed on a need to know basis, being able to customize and not to clutter the screen The green, dashed representation was considered OK if the route of a particular vessel was highlighted on rollover to make its track more salient. The routes should also be transparent not to hide important information. Use current speed to calculate the next 8 waypoints used for the intended route service (unless one of the waypoints is the final destination or otherwise designated as "critical", e.g. arrival at a lock). 42. REFERENCES ACCSEAS. 2013. Baseline and Priorities Report, v. 2 . https://www.accseas.eu/content/downloadstream https://www.w3.org/1998/Math/MathML"> / 2743 / 2572 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0/ file/ACCSEAS +Baseline+and+Priorities+Report+v2.pdf [acc. 2015-01-31] Endsley, M. R. 1988. Design and evaluation for situation awareness enhancement. In Proceedings of The Human Factors Society 32nd Annual Meeting (pp. 9 -101) Santa Monica, C.A.: Human Factors Society. Kwik, K. H. (1984). Sailing Problems Within and Near Traffic Separation Schemes. Journal of Navigation, 37: 398-406. Norman, D. 1988. The Design of Everyday Things. Basic Books. Office of the Commissioner for Marine Affairs. 1979. Decision of the Commissioner of Marine Affairs, R. L. in the Matter of the Collision of the Liberian Bulk Cargo Vessel ARTARDI (O.N. 3592) and the French RoRo/Train Ferry SAINT GERMAIN in the Dover Strait on 21 February 1979. Monrovia, Liberia: Ministry of Finance. Porathe, T., Lutzhoft, L. & Praetorius, G. 2013. Communicating intended routes in ECDIS: Evaluating technological change. Accident Analysis and Prevention, Elsevier 2013 Nov; 60:366-70 PARK Model and Decision Support System based on Ship Operator's S.W. Park, Y.S. Park & J.S. Park Korea Maritime and Ocean University, Busan, S.Korea N.X. Thanh Ho Chi Minh City University of Transport, Ho Chi Minh, Vietnam Abstract The recent situation at sea shows that, as the number of the vessels increases, the port traffic and the encounter situations also increase. Hence, minor and major marine accidents occur consistently. However, in the guidelines of the ship officers, COLREG regulation (International Convention for Regulations for preventing collision at sea) only gives the subjective expressions to avoid the collisions between the vessels, which is quite ambiguous in executing its actions to avoid the collisions. This study used the collision risk model (PARK model) that reflects the ship operator's consciousness which introduces the alarm systems and shows the degree of the risk on the screen. Moreover, it was tested in the vessels and ports with high traffics to confirm the effectiveness of the model. 43. INTRODUCTION Ships make a voyage by using all available means such as RADAR, ECDIS and other navigation equipment that consistently develop in terms of their level of performance and convenience. Nevertheless, collision accidents continue to occur around the world, bringing forth the need to develop a system to prevent and quantify such risk of collision. Therefore, we developed a tool to quantitatively evaluate the degree of danger from the perspective of the ship operator. They also validated system that would provide the ship operator with information required in avoiding collision. The research to quantify the risk of collision has been implemented mostly based on the 'fuzzy theory' that could help evaluate marine traffic situations. However, the theory has its limitation for utilization as a model to support the decisionmaking process of a ship operator since the level of risk felt by the operator is not reflected (Kim, J. S et al 2011). In order to reflect the psychological perception of the degree of danger, we divided the consideration factors into internal and external factors. The internal factors are the factors that affect degree of danger at sea and external factors affect the ship during navigation such as kinds of ship the own ship encounters and the angle of encounter. Using such factors, we conducted a survey on ship operators and ran simulations to quantify and evaluate a numerical value on ships that navigate the coastal waters of South Korea and developed a tool based on such information. Based on the evaluation model, the risk of collision between own ship and other ship as well as among other ships were assessed by using AIS information. A system was also developed to distinguish and display such data by each ship and waters. Finally, the system was validated in actual waters. 44. BACKGROUND 45. 2.1 Needs and Purpose For the last five years https://www.w3.org/1998/Math/MathML"> ( 2009 - 2013 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , among the marine accidents happened in Korean waters, a total of 423 collision cases took place and 411 cases of them https://www.w3.org/1998/Math/MathML"> ( 95.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total) occurred due to the negligence of the ship operators. It can be seen that the most of the collision accidents were caused by the negligence of the ship officers. In order to reduce these marine accidents, any factors related to the ship operators must be corrected. There are many parameters in the marine traffic. The negligence of the ship operators can be seen as an important factor among these parameters and is the main cause of the collision accidents. However, such ship operators have their own subjective minds which then show different degree of risk on the same situations occurred. This means that the ship operators voyage by the subjective judgments while VTS officers (VTSO) too, control the ships by subjective judgments. The purpose of this investigation is to voyage or control the ship by the objective judgment through the quantification of risk. 46. 2.2 Questionnaire survey 65 VTSO of the Busan Port, with the high traffic, Busan New Port, Ulsan Port and Masan Port were surveyed about the need of the tool which displays the risk of collision and its effectiveness. Figure 1 shows an increasingly positive response as an answer goes to the left of the X-axis controller, and one gets a negative answer to the right. The Y axis is the number of VTSO whom answered. 31 of the VTSO https://www.w3.org/1998/Math/MathML"> ( 51 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> answered positively to the need of the tool, while 31 of them https://www.w3.org/1998/Math/MathML"> ( 52 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> answered positively to the usefulness of the tool. As shown above, more than https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the VTSO answered that they need this tool, which displays the risk of collision and that this tool will also be useful when used at work. Table 1 shows a survey of the need for a tool which displays the risk of collision depending on the age of the VTSO. On the other hand, table 2 shows a survey on the effectiveness of the tool depending on the age of the VTSO. To conclude, it can be seen as the young VTSO about 20-30 years old tend to answer more positively when compared with the other VTSO of the age around 40-60. This seems to reflect the characteristics of the young generation familiar with the new changes. Table 1. VTSO's response about need for a tool which displays the risk of collision 1 (Positive) 3 4 5 6 (Negative) Total 20-30 's 2 7 2 4 0 0 15 40-60 's 7 15 8 7 6 2 45 Table 2. VTSO's response about effectiveness for a tool which displays the risk of collision 1 (Positive) 2 4 5 6 (Negative) Total 20-30 's 2 9 1 3 0 1 16 40-60 's 7 15 7 10 4 2 43 47. USED MODEL & TOOL 48. 3.1 PARK model Due the increased volume of trade around the world including South Korea, the number of arrival and departure has been on the rise. As a result, encounters with other vessels in coastal waters have become more frequent, escalating the potential of marine accidents. Although navigation equipment have been evolving, collision accidents continue to occur due to the limitation of ship maneuver by experience and information provided to avoid collision. In order to ensure safe navigation by providing appropriate information to ship operators, this paper used the Potential Assessment of Risk Model (PARK Model) made in 2011 (Nguyen, X. T. 2014). The PARK model is an evaluation model that assesses the degree of collision risk between ships. This model has been developed through the verification of ship handling simulator experiment and statistical analysis of questionnaire survey on 183 ship operators. It is based on ship operator's consciousness to gather and calculate directly from data of navigation instrument as AIS. The development basis of the PARK Model is a survey that was conducted on internal and external factors that affect the ship operators' recognition of degree of danger. Internal factors are tonnage, LOA, breadth, career, license factor and position. External factors are encounter situation, direction, inner harbour, outside harbour, speed and distance. The survey used a seven-point-criteria with which respondents assessed the level of danger for different situations such as encounter angle of 045 , 090,135 , overtaking and head-on situation. It was implemented on the analysis of variance and multiple comparisons on survey results to identify the difference of factors. Using the regression analysis, this model had been made. In order to validate the model derived from the survey, we used a simulated ship steering device and performed experiments on 35 different cases. We were able to confirm the validity of the model's factors and came up with an equation as follows: Risk value https://www.w3.org/1998/Math/MathML"> = 5.081905 + T p + T f + L f + W f + C f + L f + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> + P j + 0.002517 L + C j + S j + Hi / o + S p - 0.004930 × https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (1) https://www.w3.org/1998/Math/MathML"> × S d - 0.430710 × D https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> T p : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Own ship type factor In the equation stated above, the degree of danger is expressed through a value ranging from one to seven. The range between one and three is recognized as a safe situation, while the value between three and five is unsafe, and that above five is dangerous. 49. 3.2 COllision Risk Alarm and course adviser The CORAS was developed to verify the appropriateness of the PARK Model for use as a technological factor of e-Navigation. The CORAS utilizes AIS information of ships and evaluates the risk of collision between the own ship and other ship as well as that among other ships. It results of the evaluation, which is information on the degree of collision risk, is categorized by ship and waters. The flow chart of the CORAS is described in Figure 2. Based on AIS data, this can calculate own ship's collision risk against other ship. With the degree of risk, it makes an alarm under constant value. It also shows risk circle, so operator can select safe course (Park, Y. S. 2013). Figure 2. Flow chart of CORAS The composition of the CORAS is seen in Figure 3. The AIS Pilot plug is used to receive AIS information of other ships, which is passed on to the CORAS using a Wi-Fi transmitter. Figure 3. Composition of the CORAS In an environment where Wi-Fi is available, the ship operator will be able to use easily the CORAS in a remote setting. The display system of the CORAS is shown in Figure 4. The basic display system is similar to the RADAR and it can verify the degree of danger by vessels and waters through a colour code On this figure 4 , (1) is Own ship and displayed at the center. (2) is Other ship. Information of other ships is displayed using the AIS information. (3) is Own ship information. Information of own ship including GPS position, HDG, COG, SOG is displayed. (4) is Other ship information. Information of the other ship including name, GPS position, relative HDG/DISTANCE, COG, SOG, CPA, TCPA, BCR, BCT is displayed (5) is Degree of risk. The degree of risk of collision is displayed by the PARK Model. (6) is Degree of risk around the area. Degree of risk around own ship is displayed through colour code https://www.w3.org/1998/Math/MathML"> ( 1 ∼ 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> : green, 4∼5 : yellow, 5∼7 : red https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (7) is Cursor information. Displays relative HDG/distance of the other ship from the mouse cursor's position and own ship. (8) is Monitor calibration. Scale of monitor, direction of heading, rearrangement of other ship's information. The CORAS displays shiy The CORAS displays ships with a collision risk of 5.0 and above, which indicates a dangerous situation, with a red line for clear identification. It also calculates the degree of risk of collison with every other vessels 360 degrees around the own ship. For the lowest level of collision risk for every one degree is displayed on the screen with its corresponding colour code to indicate the level of risk by waters. 50. APPLICATION & VERIFICATION 50.1. Verification with real ship We conducted the verification in the coastal water in order to validate the level of risk calculated by the model. To this end, the degree of danger subjectively felt by the ship operator and that indicated by the PARK Model were compared. Verification took place on the training ship, HANBADA of KMOU (Korea Maritime and Ocean University) during a coastal voyage on 15 April 2014. In the experiment, 2 near collision situations occurred. It wasn't easy to encounter such dangerous situations in a real situation. So, the verification requested other vessel to create 2 near collision situations. Overall, the weather conditions and visibility were very good Figure 5 shows the scene of the two vessels encountered by head-on situation, range with other ship is around 2 cable. Figure 6. Display of encounter with the Eastern Express Figure 7 shows the average degree of danger felt by ship operators and that indicated by the PARK Model in the case of encounter between the Eastern Express and the test vessel. The ship operator recognized the situation as being dangerous when the distance with the other ship was https://www.w3.org/1998/Math/MathML"> 3 N M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . When the distance came up to 1NM, the OOW (Officer Of the Watch) altered the course of the ship to avoid a collision. Despite the slight gap in human perception and the result of the PARK Model, the result shows that the tendency is similar. Figure 9 shows the average degree o Figure 9 shows the average degree of danger felt by ship operators and that indicated by the PARK Model in the case of encounter between the Saenuri and the test vessel. It can be seen on the graph that the ship operator judged the situation to be dangerous when the distance with the other ship was https://www.w3.org/1998/Math/MathML"> 3 N M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . When the distance was shortened to https://www.w3.org/1998/Math/MathML"> 0.2 N M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the OOW changed the course to prevent a collision. There was a slight difference between the ship operator's degree of risk and Park Model's degree of risk, however their tendency were similar. Difference between the size of the risk could be from the limits of the model, which its accuracy should be improved in the future. officers (Saenuri) 50.2. Verification in Busan port The verification was implemented to confirm and verify ability of the CORAS to identify multiple risk factors. Figure 10 shows display of congested waterway in CORAS. It took place in Busan port, one of the busiest ports in South Korea. We installed the CORAS on the training ship, T/S HANBADA that was moored on KMOU's wharf, from which we received AIS information. The narrow entrance of Busan port gave rise to various situations, from which Figure 10 was derived. With the CORAS, we could observe multiple encounter situations, check the degree of danger from the perspective of the ownship (a) and provide a less dangerous course from the ship's position. Furthermore, it displayed in red dangerous situations from which the course shall be altered immediately (degree of danger of 5.0 and above). Figure 11 indicates the risk value of every vessel, the number of which in the case was ten, related to the ownship. Vessel B and Vessel E shows the highest degree of danger. Vessel B is the overtaken vessel and Vessel E was in a head-on situation with the own ship. The ship operator is able to refer to red-coloured information in a congested water to figure out other ships that require immediate response. Moreover, the tool allows users to confirm the degree of danger for each waters and when to change the course. 51. CONCLUSIONS For the last five years (2009-2013), among the marine accidents happened in the Korean waters, https://www.w3.org/1998/Math/MathML"> 95.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of them occurred due to the negligence of the ship operators. Any factors related to the ship operators should be corrected to reduce marine accidents. To focus on ship's operator, we used PARK model, which is an evaluation model that assesses the degree of collision risk between ships. And this model reflects ship operator's recognition. This study developed a CORAS that can be confirmed by the development of ship collision risk assessment model which applied ship operator's point of view. Not only that, this tool was used in the actual ship and at the Busan Port in order to be verified. Conclusions of this study are as follows: 1 In the survey of the VTSO around the Busan Port, https://www.w3.org/1998/Math/MathML"> 51 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of them gave the positive answers to the tool which predicts the risk of collision. 2 This study developed the CORAS to verify the appropriateness of the PARK model. With the CORAS, operator can check easily degree of danger by vessel and waters through a colour code. 3 The CORAS was applied to real ship. On situation 1, two vessels encountered by head-on situation, range with other ship is around 1 NM. On situation 2, two vessels encountered by crossing situation, range with other ship is around https://www.w3.org/1998/Math/MathML"> 0.2 N M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Even though their tendencies were similar, there was a slight difference between the ship operator's degree of risk and PARK Model's degree of risk. So, this is the part where the model must continue to adjust in the future. 4 The CORAS using the PARK model was applied at the Busan Port and was able to determine the risk for each vessel and it was confirmed that the dangerous vessel could be prominently displayed in red colour. In next step, this CORAS is ought to be applied in the field of Vessel traffic control Center. Then compare the degree of risk from the VTSO and the tool, and enhance the accuracy of the tool. 52. REFERENCES COAA 2012.ShipPlotter,www. coaac.co ú sibppiotter:htm E-Navigation tests in Southsea (S.Korea) www.yonhapnews.co.kr/bulletin Heo, T. Y., Park, Y. S, and Kim, J. S. 2012. A Study on the developmnet of Marine Traffic Risk Model for Mariners, J. Korean Soc. Transp. Vol. 30 , No. 5:91-100. Kim, J. S. 2014. A Study on the Development of Marine Traffic Assessment Model based on Vessel Operator's Risk Consciousness, Ph D. thesis, Mokpo maritime university : 7-8. Kim, J. S., Park, Y. S., Heo, T. Y., Jeong, J. Y., Park, J. S. 2011. A Study on the Development of Basic Model for Marine Traffic Assessment Considering the Encounter Type Between Vessels, Journal of the Korean Society of Marine Environment & Safety. Vol.17 No.3: 227-233 Kim, K. I. 2013. A Study on the Development of Vessel Collision Risk Assessment tool, Journal of Korean Institute of Intelligent System, Vol.23 No.3:29-30. Lee, H. K. 2011. Development of Marine Traffic Supporting System through ES Model for VTS, Ph D. thesis, Pukyong national university: 37 Nguyen, X. T. 2014. A Study on the Development of Real Time Supporting System (RTSS) for VTS Officers, Ph D. thesis, Korea maritime and ocean university : 60-65. Park, J. S., Park, Y. S. and Nha, S. J. 2014.Marine Traffic Engineering &P olicy:291-292 Park, Y. S. 2013. Estimation and Alarm Technic of Collision Risk for SOLAS Vessels including Non-SOLAS Vessel, Journal of the Korean Society of Marine Environment & Safety, Vol.2103 No.11: 145-147. Park, Y. S., Kim, J. S., Kim, C. S., Jeong, J. Y., Lee, H. K. and Jeong, E. S. 2013. A Study on the Marine Traffic Risk Assessment by using Ship Handling Simulator, Journal of Korean Society of Marine Environment, Vol. 19 No. 2:138 144. Statistics of Collision near Korea port, https://www.kmst.go.kristatistics Multi-objective Route Optimization for Onboard Decision Support R. Vettor & C. Guedes Soares Centre for Marine Technology and Ocean Engineering (CENTEC), Instituto Superior Técnico, Universidade de Lisboa, Portugal Abstract An onboard decision support system for the route selection is being developed. The intrinsic multi-objective nature of the problem is kept by adopting a widely tested and robust genetic algorithm allowing the optimization of conflicting objective such as the expected time of arrival (ETA), the fuel oil consumption https://www.w3.org/1998/Math/MathML"> ( F O C ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and the safety, resulting in a set of routes approximating the optimum in the Pareto meaning. The complete modelling of the ship responses in waves and engine performances for different seastates, ship speeds and headings will also be described. Finally a test case will allow to assess the potentialities and lacks of the tool and to discuss about the further improvements of the system. 53. INTRODUCTION One of the most crucial aspects in the ship management is the correct choice of the route. Once a ship has been built, consumptions, emissions and operability level do not only depend on the over all quality of the vessel. How it is managed in terms of cargo distribution and route selection can strongly affect the safety and the efficiency of the journey (IMO, 2009). A large amount of information regarding land distribution, dangerous or restricted areas and weather forecast in the operating area, ship's behavior in sub-ideal environment conditions in terms of sea-keeping responses and propulsion system have to be collected and jointly analyzed. Traditionally all this burden was entrusted to the masters' experience (Motte, 1985) cause to the impossibility to perform reliable weather forecast and to solve complicated optimization algorithms. Nowadays, besides acting as an emergency measure to keep or bring ships out of weather hazards (Mackie and Houghton, 1992), sophisticated routing software are increasingly recognized as an important contribution to safe, reliable and economic ship operation, that will become more and more an irreplaceable aid to the human experience for more awareness decisions. Although commercial marine weather services already exist (Ocean Prediction Center website), they are still not considered completely reliable by the ships' masters, as revealed by a series of interview (Prpić-Oršić et al., 2015). The most common claim is that weather routing software would push the vessel into too heavy storms, compromising the safety. This might be due to a too strong emphasis to the economical factor when (often) the optimization method is not intrinsically multi-objective, typically Dijkstra's algorithm (Cormen et al., 2001) is adopted (Chen, 2011) or to a poor modelling of the ship behaviour in real sea conditions, which neglects important factors (Guedes Soares, 1995; Orlandi & Bruzzone, 2012) or dangerous situations (IMO, 1995, Krata & Szłapczynska, 2012). Nevertheless there is room and need for a deeper investigation in this field in order to create more reliable software to be tailored on the requirements of the ship where they are equipped. Since the accurate prediction of voyage duration is one of the main tasks in ship navigation (Guedes Soares et al., 1998), the first generation of weather routing methods were thought only to optimize time, as for instance James (1957), Zoppoli (1972), Spaans (1986). The more recent concerns on energy efficiency and reduction of emissions (IMO, 2009; Prpič-Oršić et al., 2015) and the increasingly competitiveness in maritime trades pressured researches into multi-objective optimization. The Dijkstra's algorithm was successfully applied in the Indian Sea (Padhy et al., 2008), but it requires summarizing the objectives in a single goal function. More recently (Skoglund, 2012) the same algorithm has been slightly modified to account for multiobjectives, simply saving the Pareto-optimal results encountered during the iteration process. It showed noteworthy improvement in reducing the fuel consumption with respect to the original one. The increasing computational capabilities allowed to develop more sophisticated methods like the GIS grid based multi-objective methodology (Pacheco and Guedes Soares, 2007) and the more and more frequent employment of evolutionary programming and genetic algorithms: Hinnenthal & Saetra (2005), Szłapczynska & Smierzchalski (2007), Marie and Courteille (2009) and Maki et al. (2011). The importance of accounting for uncertainties for a conscious evaluation of the hazards is stressed in Papatzanakis et al. (2012). An advanced onboard decision support system for the selection of the preferable route is being prepared. The guideline that drives the development is a strong attention to the needs of the master, in order to be able to provide, together with the indication of the routes that better fits the requirements, all the necessary information for an aware final decision. The first vital requirement is a reliable and detailed modelling of the ship behaviour in seaways. Both the motions induced by rough weather and the combined effect of waves and wind in the propulsion performances are considered. To deal with all the complex interacting sub-systems of the weather routing optimization, a class will be dedicated to each component. To design the code with this framework since the beginning is fundamental since it will allow separately treating each problem (such as sea-keeping, propulsion system, weather, etc.), to easily replace methods and algorithms if needed and to tailor the code to the specific requirements in the real implementation. The main objective of this paper is to describe the detailed assessment of the sea-keeping responses and the propulsion system performances for many conditions of sea-states, ship speeds and headings. Section 2 is dedicated to this issue. In section 3 a brief description of the code, which adopt a multiobjective optimization algorithm for the search of the Pareto-optimal solutions is given. Finally an example will show the results of a run of the code in a specific case. 54. SHIP PERFORMANCE When the optimal routes have to be identified, first of all it is essential to be able to describe all the significant aspects of the ship in a seaway, which allows to compute the objectives. Under adverse weather conditions, the ship behaviour differs significantly from the one in still water with increased periodic motions (mainly heave, pitch and roll) and a component of added resistance due to waves, wind and, possibly, currents and other factors. These aspects, besides compromising the safety, comfort and work ability on board, due to slamming, green water, vertical and lateral accelerations and other dangerous effects, have a great influence on the propulsive system with an increased request of power in sub-optimal regimes, eventually being too demanding and out of the specific load diagram. Since waves are commonly recognized as the major cause of degraded ship performances, only the sea-state has been considered so far, but the influence of other not negligible factors such as wind and currents will be taken into account in the future. Ship modelling consists in the assessment of the sea-keeping responses and the propulsion performances in every possible weather condition (sea-state) and speed of advance. There are two ways to achieve this requirement: either to consider the specific sea-states described by means of the actual wave spectra (possibly directional) and apply them to the response amplitude operators (RAOs), or to compute off-line the ship responses for a set of more or less accurately pre-defined sea-states with a standard spectrum taken as a model for any encountered wave condition. The latter is widely adopted method cause it allows to describe the seastates through few integral parameters simplifying the calculation and reducing the computational time. However it must be considered that different spectral shapes may have an effect on the short-term wave-induced ship responses, especially in case of multi-modal spectra (Guedes Soares, 1990; Orlandi and Bruzzone 2012). As a first approach, the first method has been chosen, but the good performances of the code in terms of computational time (see section 4) encourage to study more sophisticated ship models. In order to have a more reliable description of the ship performances they have been computed for many different sea-states (Hs from https://www.w3.org/1998/Math/MathML"> 0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 15 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with a step of https://www.w3.org/1998/Math/MathML"> 1 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> T P https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> from https://www.w3.org/1998/Math/MathML"> 0 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 20 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with a step of https://www.w3.org/1998/Math/MathML"> 2 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ), headings (from https://www.w3.org/1998/Math/MathML"> 0 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 180 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with a step of https://www.w3.org/1998/Math/MathML"> 30 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) and ship speed (from https://www.w3.org/1998/Math/MathML"> 0 k n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 20 k n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with a step of https://www.w3.org/1998/Math/MathML"> 1 k n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) and saved in tables which are imported when an object of the "Ship" class is instantiated. The hydrodynamic calculations are carried out off-line with a computer code based on the strip theory (Salvesen et al., 1979), which provides the transfer functions of the motions and the added resistance. 54.1. Sea-keeping responses Starting from the RAOs and the given wave spectrum, being the real or a standard one in a parametric form, several sea-keeping performances can be computed and their relevance depends on the type of ship and the mission of the trip many standards have been proposed in the literature (Nordforsk, 1987; Dubrovski, 2000). For a containership, important factors may be the structural load due to bottom or flare slamming or damage to the cargo due for instance to green water or lateral accelerations; the operability of a passenger ship, instead, will be more influenced by comfort criteria governed by the vertical acceleration such as the motion sickness incidence (MSI); in the case offshore supply vessels, navy vessels or any other ship that must guarantee the possibility to work on the deck, attention has to be paid on the motion induced interruptions (MII). The code allows to adapt the optimization to the required strategy and to define appropriate limits for each effect. A risk coefficient is then computed, similarly to the concept adopted to define the seakeeping operability limit (see Nordforsk, 1987 , fig. 3.3), through the following equation. The ratio aims to normalize all the seakeeping effects in a value in the range https://www.w3.org/1998/Math/MathML"> [ 0,1 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> depending on the distance from the respective limit, such as 1 correspond to the most extreme conditions that the ship can stand. All the effects are however stored and are available to the user in the set of optimal routes. To run the test case (see section 4) three effects have been considered: the slamming probability, the green water and the vertical acceleration on the bridge. A slamming event occurs when the keel emerges from the water, meaning that the relative motion is greater than the draft, and, later on, impacts on it with a speed higher than the critical value calculated as in equation 2 , thus it implies the knowledge of the relative motions and velocity at bow: https://www.w3.org/1998/Math/MathML"> V CR = 0.093 gL https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The probability of keel emergency is calculated assuming the Rayleigh distribution of the peaks as: https://www.w3.org/1998/Math/MathML"> P ke = e x p ⁡ - D k 2 2 C j 2 D r j https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where D https://www.w3.org/1998/Math/MathML"> ke https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is the actual keel draft, which should take into account the trim, the sinkage and the ship's own wave and Cs is a coefficient to include the swell-up effect, here neglected. https://www.w3.org/1998/Math/MathML"> D r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is the variance of the relative motion on the bow. The probability to impact with a speed higher than the critical value is given by: https://www.w3.org/1998/Math/MathML"> P ir K R = e x p ⁡ - V Ck 2 2 C S 2 D iξ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where the variance of the relative velocity on the bow is used. From the previous considerations and assuming in first approximation the relative motion and velocity to be independent, the following equation yields: https://www.w3.org/1998/Math/MathML"> P sl = P ke ⋅ P r ε = e x p ⁡ - D k r 2 2 C S 2 D rζ - λ R 2 2 C S 2 D r j https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> For the green water effect, the freeboard exceedance is a necessary, but not sufficient condition. If the speed is not too low, in fact, most of the time the exceedance of the freeboard does not imply a green water event. Nevertheless for this study the probability of deck submergence is considered to be a good indication and it is computed with the equation: https://www.w3.org/1998/Math/MathML"> P ke = e x p ⁡ - F e 2 2 C S 2 D n j https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where https://www.w3.org/1998/Math/MathML"> F e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is the effective freeboard. The criteria on the vertical acceleration, being a varying quantity, are given on the root mean square (rms) of the variance of the vertical acceleration on the bridge: https://www.w3.org/1998/Math/MathML"> V - ac c rms = D rrζ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 55. 2.2 Propulsion system The calculation of the total resistance in irregular waves for each sea-state derives from a time-domain method proposed by Prpić-Oršić and Faltinsen (2012) where the instantaneous ship speed is calculated according to the method of Journee (1976) and Journee & Meijers (1980) by taking into account propeller in-and-out-of-water effect on ship propulsion and the effect of mass inertia. The still water resistance is calculated according to Holtrop & Mannen method (Holtrop & Mannen 1982, Holtrop 1984), an approximate procedure, which is widely used at the initial design stage of a ship. The method is based on regression analysis of random model experiments and full-scale data, available at the Netherlands Model Basin. The added resistance in waves is computed according to direct pressure integration procedure developed by Faltinsen et al. (1980). For the main engine a two-stroke electronically controlled low speed marine engine with main particular listed in table 1 is used. https://www.w3.org/1998/Math/MathML"> Table 1. Characteristics of the main engine Engine model MAN B\&W 9S50ME-C8-TII MCR 14940 k W at 127 r p m SCR 12707 k W at 120 r p m Fuel Heavy fuel oil https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Figure 1. Main engine load diagram and SFOC contours. The load diagram and the specific fuel oil consumption (SFOC) at an arbitrary load have been computer following the recommendation given by the constructor in the project guide (MAN B&W, 2010 ) and are shown in figure 1. A B-series propeller is assumed and the open water propeller characteristics are obtained with the method of Oosterveld and van Oossanen (1975). The required brake power and the respective number of revolutions for all the considered conditions (in term of https://www.w3.org/1998/Math/MathML"> H s , T P https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , heading and ship speed) are then computed considering the thrust and the wake fractions computed with Holtrop method (1984) From a simple comparison of the demand and the engine output, it is easy to obtain the fuel consumption per nautical mile for each condition, that is then used to compute the fuel oil consumption for each track and, finally for the whole route. 56. SOFTWARE DESCRIPTION Due to the intrinsic nature of the problem, the best route does not exist. Instead a compromise among conflicting objectives has always to be found and it usually depends on the type of ship and the decisions of the captain. In this perspective, the multi-objective optimization is aimed to produce a set of favourable route variants making the user aware of their values and lacks enabling a conscious decision-making process for the final ranking and selection. This concept is the base of the Pareto theory. A solution is Pareto-optimal if an improvement of one objective result in the impairment of another one. The Pareto frontier is the border between the feasible and unfeasible solutions and contains the closest routes to the ideal optimal (and in the general case unfeasible) one. Among them the best possible compromise to satisfy the request can be found. 57. 3.1 Code A https://www.w3.org/1998/Math/MathML"> C + + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> code that integrates the multi-objective optimization performed by a robust genetic algorithm SPEA2 (Strength Pareto Evolutionary Algorithm 2) proposed by Zitzler et al. (2002), has been developed. It takes care of the description of the sailing area, the weather condition as well as the modelling of the ship behaviour in the seaways, in terms of seakeeping responses and propulsive performances, and, ultimately, of the optimization of the route. The code consists in six classes: "Ship", "Journey", "Route", "Domain", "Land" and "Weather"; and five subclasses: "GeoPoint", "Time", "Seakeeping", "Engine" and "Environment". The architecture was designed to be flexible to future upgrades or modifications and to be completely controlled through simple input files. 58. 3.2 Genetic operators The initial population is made of random routes that are computed respecting the constrains. The ship performance is computed for many short tracks https://www.w3.org/1998/Math/MathML"> ( 30 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> miles in the case study in section 4) along the route, in order to ensure the weather condition to be stationary for each track. The variation to produce the new generations is performed through three genetic operators: crossover, mutation and migration. In the crossover two routes (parents) are randomly chosen from the selected set, as well as one of the waypoints ( https://www.w3.org/1998/Math/MathML"> k th https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> waypoint). All the parameters (that is grid-point indices and ship speed) up to the https://www.w3.org/1998/Math/MathML"> k th https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> waypoint are copied from the first to the new route (offspring), while from the https://www.w3.org/1998/Math/MathML"> ( k + 1 ) th https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to the https://www.w3.org/1998/Math/MathML"> nW P th https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are copied from the second parent. In the mutation one individual is randomly chosen from the selected set as well as one of the waypoints, then the parameters relative to the detected waypoint are randomly varied ensuring the respect of the previously defined limitations. The mutation operator has usually a very low probability; nevertheless in this case it revealed a great capability of refining the routes in the proximity of the Pareto frontier, especially in an advanced stage of the optimization. The migration simply consists in the generation of a new random route. This operator is often neglected in the genetic algorithms and can here be excluded. 59. 3.3 Objectives Although with a different extent in consideration of the ship, any navigation requires to reach the destination in a pre-determined or as short as possible time, in safe conditions and, especially when a weather routing system is adopted, to save fuel that likely also imply lower emissions. For this reason the classical objective in route optimization are the fuel oil consumption https://www.w3.org/1998/Math/MathML"> ( F O C ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the estimated time of arrival (ETA) and the safety (SAFETY). Instead of using the actual values of the objectives, the following objective functions were introduced for the last two targets: https://www.w3.org/1998/Math/MathML"> FO C obj = 1 - FO C m i n / FO C journey 2 ET A obj = 1 - ET A m i n / ET A joumey 2 SAFET Y obj = k ⋅ RIS K coeff 2 k = 1 - ET A m i n / ET A journey https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where FOC min is the minimum fuel oil consumption achieved in calm waters at the most efficient optimal engine load, ETAmin is the minimum possible duration of the journey if the shortest route is sailed at the design speed and k, given in equation https://www.w3.org/1998/Math/MathML"> 8 d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is a factor adopted to discard routes which are safe but practically useless for the optimization cause of the excessive duration. These functions help to accelerate the propagation of the initial routes towards the optimal solutions, a skill that is especially important in case of rough sea or land avoidance when the respect of the constrain might slow down the creation and recombination of feasible individuals. Furthermore the objective function relative to the safety reduces the impact of meaningless routes, which minimize the slamming probability, but imposing weird courses. 60. 3.4 Selection Once the stopping criterion is achieved, the postprocessing starts. It consists in writing a series of files to allow the quick visualization of all the route parameters (time of departure, expected time of arrival, sea-states that the ship will encounter, seakeeping responses, etc.) and the file for the plots. In this phase a ranking method is also applied. In this case the distance of each route from the utopia point in the objective space determines the rank. 61. EXAMPLE A test case was run considering the S175 containership as a reference. The simulation is performed for a route between the port of Sines in Portugal and the entrance of the entrance of the Gulf of Saint Lawrence. The departure time is set at https://www.w3.org/1998/Math/MathML"> 9.00 p m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on January https://www.w3.org/1998/Math/MathML"> 31 s t , 2001 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in order to include in the travel period the evolution of a storm occurred between February 4th and 5 th, identified analysing the HIPOCAS (Hindcast of Dynamic Processes of the Ocean and Coastal Areas of Europe) hindcast database (Pilar et al., 2008). This database contains 44 years of wind and wave data in the North Atlantic in a grid of https://www.w3.org/1998/Math/MathML"> 2 ∘ × 2 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and every three hours. Figure 2. Resulting Pareto frontier after 1000 generations. Figure 3. Paths of three of the Pareto frontier routes: smallest FOC (red stars), shortest time (red dots) and safest (red triangles). Figure 4. Speed profile of the routes depicted in figure 3: smallest FOC (first), shortest time (second) and safest (third), plus the first rank given in the selection process (fourth). Relatively to the genetic algorithm, the dimension of the first generation is of 100 individuals, while in each generation the mating pool is of 15 individuals and 15 offspring are generated. The number of generation is 1000 . The run took around 15 minutes. Most of them are however dedicated to the initialization, in particular the reading of the bathymetry is quite demanding due to the large amount of data, but the computation of the first random generation is the most time-consuming routine, requiring almost 10 minutes cause to the presence of the heavy storm that imposes many tries to respect the constrains (runs in milder weather conditions, not shown here, are much faster). In figure 2 the obtained Pareto frontier shows a good distribution of the results. In figure 3 the paths of the best routes among the selected ones in terms of minimum fuel oil consumption, shortest duration of the trip and smallest risk are shown, while the speed profiles are plotted in figure 4. A comparison of the 2 figures gives a clear view of the effect of the optimization of the different objectives. The fastest route takes 144 hours, it stays more north to reduce the distance and keeps an higher average speed https://www.w3.org/1998/Math/MathML"> 16.4 k n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , remaining out of the storm but close to the borders where waves can be quite heavy (the maximum encountered wave height is https://www.w3.org/1998/Math/MathML"> 5.5 m ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . To save fuel the speed of advance is cut and maintained around https://www.w3.org/1998/Math/MathML"> 12.5 k n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for great part of the journey. Waves are still considerably high, but the fuel consumption is reduced by https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> respect on the previous route but taking one and a half day more to reach the destination. The safest modulates the speed in order to reduce the ship motions but also circumnavigates the storm at a greater distance to avoid the tail. The first rank route seems a good compromise. It takes 14 hours more than the fastest one, using https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> less fuel. It must be noted that even in this case rough weather condition are encountered, but always respecting the sea-keeping constrains. It is due to the presence of an heavy storm in the period of the passage. If more safety or comfort are required, once can set stricter constrains before the running or just chose another route in the rank. In the future a more flexible ranking method will be adopted. 62. CONCLUSIONS The progresses in the development of an onboard decision support system have been described. Special attention was given to the modeling of the ship performance in terms of sea-keeping responses and propulsion system. Other important, but more critical sea-keeping effects must be included, in particular the roll motion in order to limit the occurrences of heavy beam sea. The optimization algorithm confirmed to be appropriate to deal with this problem, with a smooth distribution of the results in the Pareto frontier. The ranking method needs to be studied more accurately in order to be more flexible to the request of the decision-maker and to allow a re-selection if the first choice is not considered adequate. The analyses of the computational time, deeper than the one discussed in section 4 , indicates that the most critical part of the optimization is the construction of the first generation, while the calculation of the ship behavior is quite fast, in spite of the quite high resolution of the computation point along each route. This encourages to attempt an even more accurate modeling of the ship and the weather including comparison of the wave actual wave spectra and the RAOs in the code. This would allow to identify the possible dangerous situations due to the actual frequency distribution of the wave energy, especially in the cases of multi-modal spectra, and more in general to be more precise in the computation of the ship performances, thus in the optimization of the route. 63. AKNOWLEDGMENTS This work was performed within the project SHOPERA-Energy Efficient Safe SHip OPERAtion, which was partially funded by the EU under contract 605221 . The first author was supported by the Portuguese Foundation for Science and Technology (FCT Fundaçåo para a Ciência e Tecnologia, Portugal) under the contract no. SFRH/BD/89476/2012. 64. REFERENCES Amante, C. and B.W. Eakins, 2009. ETOPO1 1 Arc-Minute Global Relief Model: Procedures, Data Sources and Analysis. NOAA Technical Memorandum NESDIS NGDC-24. National Geophysical Data Center, NOAA Chen, H. (2011). Voyage optimization supersedes weather routing. Technical report, 2011. Cormen, T.H., Leiserson, C.E., Rivest, R.L., Stein, C. (2001). "Section 24.3: Dijkstra's algorithm". Introduction to Algorithms (Second ed.). MIT Press and McGraw-Hill. pp. 595-601. Dubrovaskiy, V.A. (2000). Complex Comparison of Seakeeping: Method and Example. Marine Technology, 37(4), 223-229. Faltinsen, O.M. Minsaas, K.J. Liapis, N. Skjordal, S.O. (1980). Prediction of Resistance and Propulsion of a Ship in a Seaway, Proc. 13 th Symposium on Naval Hydrodynamics, pp. 505-529. Guedes Soares, C. (1990). Effect of Spectral Shape Uncertainty in the Short Term Wave-Induced Ship Responses. Applied Ocean Research, 12(2), 54-69. Guedes Soares C. (1995) Effect of wave directionality on longterm wave-induced load effects in ships. Journal of Ship Research, Vol. 39 , No. 2, pp. 150-159. Guedes Soares, C., Fonseca, N., Ramos, J. (1998). Prediction of Voyage Duration with Weather Constraints. Proceedings International Conference on Motions and Manoeuvrability, Royal Institute of Naval Architects, London. Hinnenthal, J., Saetra, O., (2005). Robust Pareto - optimal routing of ships utilizing ensemble weather forecasts. Maritime Transportation and Exploitation of Ocean and Coastal Resources, C. Guedes Soares, Y. Garbatov and N. Fonseca eds., Taylor & Francis Group, London, UK, pp 1045-1050. Holtrop, J. A. & Mennen, G.G.J. (1982). An Approximate Power Prediction Method. International Shipbuilding Progress, Vol. 29, pp. 166-170. Holtrop, J. A. (1984). Statistical Reanalysis of Resistance and Propulsion Data. International Shipbuilding Progress, Vol. 31 , pp. 272-276. IMO (1995). Guidance to the Master for Avoiding Dangerous Situations in Following and Quartering Seas. MSC/Circ. 707 MSC/Circ.707. Efficiency Operational Indicator sheling(EEOD). MEPC. 1/Circ.684. IMO (2009). Report of the Marine Environment Protection Committee on its Fifty-ninth Session. MEPC 59/24. James R.W. (1957). Application of wave forecast to marine navigation. Washington: US Navy Hydrographic Office. Journee, J.M.J. (1976). Prediction of Speed and Behaviour of Ship in a Seaway. International Shipbuilding Progress, Vol. 23, No. 265, pp. 1-24. Joumee, J.M.J., Meijers, J.H.C. (1980). Ship Routeing for Optimal Performance. Transactions IME, Rapport 0529 P, Delft Krata P. & Szłapczynska J. (2012). Weather Hazard Avoidance in Modeling Safety of Motor-Driven Ship for Multicriteria Weather Routing. TransNav - International Journal on Marine Navigation and Safety of Sea Transportation. Vol. 6. No. 1. pp. 71-78. Kreysig, Erwin, Advanced Engineering Mathematics, Third Edition, John Wiley and Sons, Inc., 1972. Mackie, G.V. & Houghton, J.F.T. (1992). Marine Meteorological Services to Shipping, Past, Present and Future. Joumal of Navigation. Vol. 45, pp. 241-246. Maki, A., Akimoto, Y., Nagata, Y., Kobayashi, S., Kobayashi, E., Shiotani, S., Ohsawa, T., Umeda, N. (2011). A new weather-routing system with real-coded genetic algorithm Journal of Marine Science and Technology. 16:311-322. MAN B&W (2010). S50ME-C8-TII - Project Guide. 19875 86-7.1. Marie S. & Courteille E. (2009). Multi-Objective Optimization of Motor Vessel Route. TransNav - International Journal on Marine Navigation and Safety of Sea Transportation. Vol. 3. No. 2. pp. 133-141 Motte, R. (1985). Weather Routing of Ships for the Northern Oceans. Journal of Navigation. Vol. 38, pp. 274-282. Nordforsk (1987). Assessment of Ship Performance in a Seaway. The Nordic Co-operative project: "Seakeeping Performance of Ships". Nordic Cooperative Organization for Applied Research. Ocean Prediction Center, National Weather Service, National Oceanic and Atmospheric Administration. https://www.opc.ncep.noaa.gov/links.shtml. Oosterveld, M.W.C. & van Oossanen, P. 1975. Further Computer-Analyzed Data of Wageningen B-Screw Series, I.S.P., Vol. 22, No. 251 , Wageningen Orlandi, A. & Bruzzone, D. (2012). Numerical weather and wave prediction models for weather routing, operation planning and ship designs: the relevance of multimodal wave spectra. Sustainable Maritime Transportation and Exploitation of Sea Resources. Rizzuto & Guedes Soares (eds). Taylor & Francis Group, London, pp. 817-826. Pacheco M.B., Guedes Soares C. (2007). Ship Weather Routing Based on Seakeeping Performance. Advancements in Marine Structures. Guedes Soares, C. & Das, P.K. (Eds). London, U.K.: Taylor & Francis Group; pp. 71-78. Padhy, C.P. , Sen, D., Bhaskaran, P.K. (2008). Application of wave model for weather routing of ships in the North Indian Ocean. Natural Hazards Vol. 44 (3), pp. 373-385. Papatzanakis, G.I., Papanikolaou, A.D., Liu. S. (2012). Optimization of Routing with Uncertainties, Sustainable Maritime Transportation and Exploitation of Sea Resources, Rizzuto, E. & Guedes Soares, C (Eds), Taylor and Francis Group, pp 827-835. Pilar P., Guedes Soares C., Carretero J.C. (2008). 44-year wave hindcast for the North East Atlantic European coast. Coastal Engineering 55, 861-871. Prpič-Oršič, J., Faltinsen, O.M. (2012), Estimation of Ship Speed Loss and Associated https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Emissions in a Seaway. Ocean Engineering, Vol. 44, No 1, 1-10 Prpić-Oršić, J., Vettor, R., Guedes Soares, C., and Faltinsen, O.M. (2015) Influence of ship routes on fuel consumption and https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> emission, Maritime Technology and Engineering. Guedes Soares, C. & Santos T.A. (Eds.). Taylor & Francis Group, London, UK, pp. 857-864. Prpič-Oršič, J., Parunov, J., Šikić, I. (2014). Operation of ULCS - real life. International Joumal of Naval Architecture and Ocean Engineering, Vol. 6, pp. 1014 1023 . Skoglund, L. (2012). A new method for robust route optimization in ensemble weather forecasts. KTH, School of Engineering Sciences, Master's thesis. Spaans J.A. (1986). Windship routeing. Technical University of Delft. Szlapczynska, J., Smierzchalski, R. (2007). Multiobjective Evolutionary Approach to Weather Routing For Vessels with Hybrid Propulsion, Proc. https://www.w3.org/1998/Math/MathML"> 14 th https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Adv. Computer Systems. Zitzler, E., Laumanns, M., Thiele, L. (2002). SPEA2: Improving the Strength Pareto Evolutionary Algorithm for Multiobjective Optimization. Evolutionary methods for design, optimizations and control with application to industrial problems (EUROGEN 2001), K.C. Giannakoglou and others, eds, Intemational Center for Numerical Methods in Engineering (CIMNE), pp. 95-100. Zoppoli, R. (1972) Minimum-time routing as an N-stage decision process. Journai of Applied Meteorology, 11, 42943 . Simulation-Augmented Methods for Manoeuvring Support - On-Board K. Benedict, M. Kirchhoff, M. Gluch, S. Fischer & M. Schaub Hochschule Wismar, University of Applied Sciences - Technology, Business and Design, Warnemūnde, Germany M. Baldauf World Maritime University, Malmō, Sweden Abstract The shi doing on the other hand. for the following or even for series of manoeuvring segments. During the previous TRANSNAV conference in 2013 a fast-time simulation tool box was introduced to simulate the ships motion with complex dynamic models and to display the ships track immediately for the intended or actual rudder or engine manoeuvre in the ECDIS (Benedict et al., 2013). These "Simulation-Augmented Manoeuvring Design and Monitoring" - SAMMON tool box will allow for a new type of design of a manoeuvring plan as enhancement exceeding the common pure way-point planning - and it will play an important role in future education and training in simulators for ship handling. 65. INTRODUCTION This opens up chances for the application of the new "Fast-Time Manoeuvring Simulation Technology" (FTS) developed at the Institute for Innovative Ship Simulation and Maritime Systems (ISSIMS). It calculates within one second of computing time up to 1000 seconds of manoeuvring time by a very complex shipdynamic simulation model for rudder, engine and thruster manoeuvres. This enables the online prediction of all manoeuvres carried out by the conning officer for the observing officer, too. So it is easy for all officers to see whether the manoeuvring actions have at least the correct tendency and even more the effectiveness of the manoeuvres can be improved. This new type of support is called Simulation-Augmented Manoeuvring Design and Monitoring (SAMMON) - it allows not only overlooking the next manoeuvring segment ahead but also Currently, this technology is used within two new research projects: The Project COSINUS (Co-operative Ship Operation in Integrated Maritime Traffic Systems) sets out for implementing the FTS technology into integrated ship bridges and to also communicate the manoeuvre plans and display it to VTS centres. Within the European project MUNIN (Maritime Unmanned Navigation through Intelligence in Networks) this technology will be used to investigate if it is possible to steer autonomous ships where the information for manoeuvring the ship will be delayed due to the communication links. During the INSLC 17 conference new concepts were presented for innovative organisational structures specifically for bridge management (Hederstrom, 2102). This paper presents the potential of the new method specifically for the support of manoeuvring of ships both for the new manning concept and even for shore-based support or moreover for autonomous ships. Manoeuvring of ships is and will be a humancentred process despite of expected further technological developments. Most important elements of this process are the human itself and the technical equipment to support its task. However, most of the work is to be done manually because even today nearly no automation support is available for complex manoeuvres. Up to now there was nearly no electronic tool to demonstrate manoeuvring characteristics efficiently or moreover to design a manoeuvring plan effectively. However, due to the new demands there is a need to prepare harbour approaches with complete berth plans specifically in companies with high safety standards like cruise liners. These plans are necessary to agree on a concept within the bridge team and also for the discussion and briefing with the pilot. For increasing the safety and efficiency for manoeuvring real ships, the method of Fast-Time Simulation will be used in future - even with standard computers it can be achieved to simulate in 1 second computing time a manoeuvre lasting about to 20 minutes using innovative simulation methods. These Fast-Time Simulation tools were initiated in research activities at the Maritime Simulation Centre Warnemuende (MSCW) which is part of the Department of Maritime Studies of Hochschule Wismar, University of Applied Sciences Technology, Business and Design in Germany. They have been further developed by the start-up company Innovative Ship Simulation and Maritime Systems (ISSIMS GmbH) A brief overview is given for the modules of the FTS tools and its potential application: SAMMON is the brand name of the innovative system for "'Simulation Augmented Manoeuvring Design & Monitoring". It is made for both: Application in maritime education and training to support lecturing for ship handling to demonstrate and explain more easily manoeuvring technology details and to prepare more specifically manoeuvring training in ship-handling simulators (SHS) environment and Application on-board to assist manoeuvring of real ships e.g. to prepare manoeuvring plans for challenging harbour approaches with complex manoeuvres up to the final berthing/unberthing of ships, to assist the steering by multiple prediction during the manoeuvring process and even to give support for analysing the result, And SAMMON contains the following modules: Manoeuvring Design & Planning Module to design ships-manoeuvring concepts as "manoeuvring plan" for harbour approach and berthing manoeuvres (steered by virtual handles on screen by the mariner) Manoeuvring Monitoring & Multiple DynamicPrediction Module: monitoring of ships manoeuvres during simulator exercises or manoeuvres on a real ship using bridges handles, display of manoeuvring plan and predicted manoeuvres in parallel. It calculates various prediction tracks for full ships-dynamic simulation and simplified curved-headline presentation as look ahead for future ships motion. - Manoeuvring Simulation Trial & Training Module: ship handling simulation on laptop display to check and train the manoeuvring concept (providing the same functions as monitoring tool; steered by virtual handles on screen) SIMOPT is a simulation-optimiser software module based on FTS for optimising standard manoeuvres and modifying ship math model parameters both for simulator ships and for on board application of the SAMMON system. SIMDAT is a software module for analysing simulation results both from simulations in SHS or SIMOPT and from real ship trials: the data for manoeuvring characteristics can be automatically retrieved and comfortable graphic tools are available for displaying, comparing and assessing the results. The SIMOPT and SIMDAT modules were described in earlier papers (Benedict et. al: 2003, 2006) for tuning of simulator-ship model parameters. The modules for Multiple Dynamic Prediction & Control to be used on board as steering assistance tool and later the manoeuvring design and planning technology were described later (Benedict et. al: 2012,2014 ). In this paper, the focus will be laid on the potential of the SAMMON software supporting ship operations in a collaborative way on-board and ashore. 66. FUNCTION-BASED BRIDGE ORGANISATION 67. 2.1 Functional Positions The concept of Function-Based Bridge Organisation was introduced by Hans Hederstrom at the INSLC Conference in 2012. Acknowledging that all humans may make errors, the function-based bridge organization introduces organizational countermeasures to detect and manage human error before it leads to any negative consequence. It can help to remove hierarchical barriers and enhance teamwork and communication, if a traditional rankbased system has been replaced by a function-based bridge organization. The function-based bridge organization does not diminish the authority of the Master. The Master assigns officers to the particular functions based on watch-keeper competence and experience with the upcoming operation, making it a very adaptable system. The system builds on the airline concept by introducing Navigator and Co-Navigator functions. The Navigator who is conning the ship is required to communicate intentions and orders to the CoNavigator. This means that no course changes or engine orders will be carried out without a confirmation from the Co-Navigator. These new protocols also require a double watch-keeping system with a minimum of two bridge officers on watch at all times the ship is at sea. For ships with a single watch-keeping officer and a lookout on watch, the system may be somewhat more difficult to introduce. However, with trained and engaged lookouts there are definitely advantages to gain. When the Captain joins the bridge team, there is no problem to use the function based system. The best way to apply the system in this situation would be if the Captain takes on the function as CoNavigator, leaving the watch officer to continue conning the ship. The following definitions were given and the following assigned tasks are included in these procedures (only extracted items specifically for manoeuvring aspects) in Figure 1: Operations Director: Overview of the entire bridge operation, ensuring that it is, at all times, carried out in accordance with these procedures; Direct monitoring of both the Navigator and CoNavigator, ensuring that safe passage is maintained and that no internal or external influences are permitted to distract them from their primary tasks; Monitors workload and transfers tasks between functions as circumstances dictate; Unless directed otherwise by the officer with the charge, will conduct the Pilot exchange briefing; If the Operations Director takes the conn, then the position of Operations Director must be re-established as soon as possible. Navigator: Responsible for conning, navigating the ship following the approved passage plan and collision avoidance. Ensure that the bridge team (including the Pilot) is aware of planned actions and intentions by "Thinking Aloud". If a pilot has the conn, the Navigator should ensure the Pilot's intentions and planned actions are understood in advance by all bridge team members and agreed upon by the Navigator. If s/ he has the charge, the Navigator is responsible for taking back the conn from the Pilot whenever s/ he determines that doing so is necessary or appropriate for the safe navigation of the vessel. Co-Navigator: Monitors and cross checks the actions of the Navigator. Supports, challenges, and recommends actions to the Navigator. Notifies the Master or Second in Command whenever s/he has reason to believe that the Navigator has taken or plans to take any action that violates the Master's orders or is inconsistent with the safe navigation of the vessel. Monitors and cross checks the ship's position against the passage plan using real time navigation methods. Monitors traffic and collision avoidance. Unless directed otherwise by the officer with the charge, is responsible for external VHF (may be delegated to the Pilot) and liaison with the ECR. Administrator: Responsible for fixing the ship's position when paper charts are in use. Responsible for alarm management and actions. Alarms to be identified as either urgent or non-urgent alarm. Responsible for internal communications as directed. Responsible for logbook entries, checklist management and status board. Ancillary tasks as assigned. Lookout: Maintains all around lookout by sight and by hearing, reporting all sightings and/or sound signals to the Navigator, unless otherwise directed. Maintains awareness of planned intentions and reports any necessary clearances before an alteration of course. Must be able to give full attention to the keeping of a proper lookout, and no other duties shall be undertaken or assigned which could interfere with the task. Be available to interchange duties with the Helmsman. The duties of the Lookout and the Helmsman are separate. The Helmsman shall not be considered the Lookout while steering. Helmsman: Acknowledge and execute steering orders given by the person with the conn. Advise the person with the conn of any steering concerns. 68. 2.2 The Captain as a Leader instead of an Operator It is up to the Captain to decide who should fulfil any of the four functions. A Risk Factors Table and a Risk Analysis and Bridge Manning Level Table have been developed to assist the Captain in deciding what manning level to set. Those manning levels are to be seen in Figure 1. The philosophy behind the system encourages the Captain to assume the role of Operations Director, acting as a leader while the team undertakes the operation By delegating the operational tasks, he demonstrates trust in his team. This has many positive effects, such as: enhanced learning; readiness to actively participate in problem solving; enthusiasm and motivation to work; and an engaged team directly leading to increased safety and efficiency. As officers are allowed to conduct the vessel, they will be better prepared for their promotion when time comes. This will normally also increase job satisfaction, which facilitates officers? retention rate. Within this paper some elements are presented on how the communication with in the bridge team can be supported by the Fast Time Simulation Modules of the SAMMON System 69. SIMULATION-AUGMENTED SUPPORT FOR 70. 3.1 Pre-planning with "Manoeuvre Planning & As an example for creating a berth plan and briefing the navigational officer, a berthing scenario is chosen for a harbour area - the starting situation and the environmental conditions within this area on a sea chart is to be seen in Figure 2. The objective is to berth the ship with port side alongside Grasbrook Berth at Hamburg Port. The respective harbour area is being divided into two manoeuvring sections following a specific aim: 1 Section 1: At the end of this section the speed over ground (SOG) should be around https://www.w3.org/1998/Math/MathML"> 3 k n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and the heading slightly towards southeast as preparation for section 2. 2 Section 2: A state should be reached, where the ship can be held in the current at a position with constant heading and no speed. Then, the ship can then crab towards the berthing place mainly by means of thrusters. The current can be used as an additional supporting aid to go alongside. In a conventional briefing only these rough indications of the manoeuvring status can be used to develop a potential strategy for berthing the ship. The manoeuvres and setting of engines, rudders and thrusters cannot be discussed in detail because no specific manoeuvring characteristics are available for the specific situations. Figure 1. Required Functions and Manning Concept for Functional Approach for Bridge Operation Figure 2. Exercise area and environmental conditions in Port of Hamburg for berthing scenario, divided into two sections for planning the manoeuvres Figure 3. MP0 - Initial position: The prediction already showspositionsWith the new fast-time simulation there is the chance for designing a manoeuvre plan as a detailed strategy with the specific settings at distinguished positions called the Manoeuvring Points (MP). In the following, the course of actions is described in a series of figures to make a full manoeuvring plan by means of the control actions at the manoeuvring points, MP. In Figure 3 the initial position is to be seen where the instructor has set the ship in the centre of the fairway. The prediction already shows that the ship would drift slightly to port side due to the set handle positions. It can be learned that therefore the rudders have to be put slightly to starboard at the very beginning in order to follow the straight track until the next MP 1. At MP 2 the rudders are set amidships again and both propulsion units are used to slow down and to steer the ship: the starboard engine is kept at https://www.w3.org/1998/Math/MathML"> 34 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , resp. 43 rpm to allow for a certain rudder effectiveness for steering control, whilst at MP 3 the portside engine is set backwards in order to achieve about https://www.w3.org/1998/Math/MathML"> 3 k n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> SOG at the end of section 1. In Figure 4 (top), the ship is stopped at MP4: The vessel's heading is chosen in that way, that all handles can be set in zero position, holding the ship with a minimum speed almost at the same position. At this moment, bow and stern thrusters can be applied to bring the ship safely to its berth. In the bottom figure the ship is already brought to the berth. The crabbing by means of bow and stern thrusters needs a further MP5 in order to reduce the transversal speed shortly before berthing at MP6. the ship would drift slightly to portside due to the set handle https://www.w3.org/1998/Math/MathML"> ( 2 s e i e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Figure 4. Final part of the manoeuvring plan: At MP4 the vessel is stopped and the heading is chosen in that way, that all handles can be set in zero position (Top); at MP5/MP6 the ship is already brought to the berth (Bottom) The complete manoeuvring plan can be saved to be used for the training or to be loaded again for editing the plan for an optimisation to achieve a better performance e.g. to do the whole manoeuvre in less time. For an in-depth discussion at the separate manoeuvring points and sections, there is the possibility to save the specific conditions as situation files. These situation files can be useful for discussing strategies during the planning at different places where new challenges will come up as well as for the debriefing sessions. In Figure 4 at the right bottom corner the time is to be seen for the complete series of segments: the total manoeuvre time is about 17.5 minutes for this version of the plan. 3.2 Berthing making use of Simulation-augmented support in SHS and with SAMMON Monitoring Module and Training Tool During the exercise it is possible to take advantage from the multiple predictions for the manoeuvres. In Figure 5 an example is shown for the On-line manoeuvre prediction (dotted ship contours) starting from current position (black ship contours) at the end of black past track. On the ship bridge the prediction is controlled by the handles on the manoeuvring controls. For training and test purposes the manoeuvre can also be tested in the SAMMON Trail & Training Tool - in this software the controls are used to be seen in the Monitoring & Control Interface of the Training Tool presented on the right side in this figure. For comparing the effectiveness of the simulation-augmented support tools a simulator test was made with trainees who have no support and trainees who have parts or even the full support of the SAMMON. During the exercise it is possible to take advantage from the multiple predictions for the manoeuvres. The students can bring their own laptop onto the simulator bridge (where he has already developed the manoeuvring plan), the prediction is controlled via the bridge handles, and another laptop with the monitoring tool can also be placed at the instructor station. In Figure 6 a comparison is made between the two simulator results of the trainees with different level of preparation and the manoeuvring plan of the second trainee. The achievements of the better prepared trainee are obvious - the planned manoeuvre is very close to the executed track and the actions of the controls has been done also nearly in accordance with the planned procedures. It is obvious that there is not just a reduction of manoeuvring time when applying the Fast-Time Simulation tool in briefing and training; the thruster diagrams show also that a well prepared manoeuvre can minimize the use of propulsion units and therefore be more efficient. Figure 5. Example for overlay of a pre-planned manoeuvre plan (MP) as manoeuvring basis (blue) and manoeuvre prediction (dotted ship contours) starting from current position (black ship contours) at the end of black past track with her engines ordered in opposite direction presented in Monitoring & Control Interface of the Training Tool (right) Figure 6. Results from two manoeuvring exercises in SIMDAT interface with ships track and time history of thruster activities. (Blue: run of the trainee without support by Fast-Time Simulation; Green: run of the trainee with full support by preSimulation; Green: run of the trainee with full support by preplanning with Design and Planning Module; Red: comparison The benefit of using the FTS is to be seen for several purposes: The multiple dynamic predictions are always a great help for the Navigator steering the ship: They have a better overview on the current situation and the chances for the potential success of an action can immediately be seen; also for the Co-Navigator there is the chance to see both the manoeuvres and the success - this is a great situation because they can both share a better situation overview. Multiple dynamic predictions may be used to see both the current state of motion by the static path prediction and the future development of the ship motion caused by the current handle settings - it is expected that the static prediction changes into the dynamically predicted track, in this case the pre-diction is correct. If not then the handle settings can be slightly adjusted to correct for the tendency of the potential impact of environmental effect which might not have been considered by the dynamic prediction, e.g. a non-detected current. 71. RESEARCH PROJECT COSINUS - SIMULATION AUGMENTED MANOEUVRING FOR BRIDGE OPERATION AND FOR VTS The goal of the project COSINUS ("cooperative operation of ships for nautical safety through integration of traffic safety systems) is to achieve the integration of maritime traffic safety systems on board and on shore. Therefore, novel concepts are investigated regarding the presentation of enhanced data to the operator and operation of new tools and services as well as decentralized data capturing, processing and storage. Processed data of land-based information systems will be visualized in such a way that a complete overview over the traffic and environmental situation is given in order to support the navigational operation of the vessel. This includes e.g. the representation of a shared route and manoeuvring plan, the operational interface to the VTS operator, and the depiction of weather-data along the voyage or at the destination port. The goal is to establish a cooperative picture which offers a dynamically enhanced view for the bridge crew going beyond traditional ship-based sensor information like own ship RADAR or AIS. This will improve the safety particularly in heavy traffic situations. A great deal of work will be carried out concerning the definition and establishment of new standards for the ship based navigation in cooperation with higher level traffic management systems. The main areas of work are the following: Visualization concept for representation of landbased information on ship bridges The proposal and the validation of modules and interfaces for autonomous communication between VTS and INS Combination of ECDIS representation of navigational data and VTS data to an integrated navigational and traffic picture Concept for cooperative route- and manoeuvre planning Investigation of communication channels and interfaces for exchange between VTS and INS Specifically for the integration of the SimulationAugmented Manoeuvring Support by SAMMON the new functions have to be interfaced: The results of the manoeuvre planning have to be made available into the Integrated Bridge System and Also the data transfer from ship data into the Monitoring and Control Module have to be adjusted. The data transfer from ship to shore into the VTS centre has to be established. The concept for sharing the information between ship and shore is to be seen in Figure 7- both on the bridge and in the VTS the same display elements for planned routes and manoeuvres can be observed on all screens in the same way. In Figure 8 a first result is to be seen for a ship station to display the manoeuvring plan together with a route plan of another vessel. Figure 7. Project COSINUS - shared information on manoeuvring plans and multiple prediction in ECDIS between bridge and VTS Figure 8. Project COSINUS results: Display of manoeuvring plan (green) of own ship together with route plan of another vessel (blue) presented in Integrated Navigation System of project partner Raytheon Anschütz transmitted from VTS station from SIGNALIS 5 RESEARCH PROJECT MUNIN MANOEUVRING SUPPORT FOR AUTONOMOUS SHIPS 72. 5.1 Introduction & Objectives Maritime Unmanned Navigation through Intelligence in Networks (MUNIN) is a collaborative research project of eight partners from five European countries co-founded by the European Commission. MUNIN's aim is the development of an autonomous-ship concept and its simulationaugmented feasibility study. MUNIN Project coordinator is the Fraunhofer Center for Maritime Logistics and Services (CML) in Hamburg, Germany. The Department of Maritime Studies at Hochschule Wismar (HSW), University of Technology, Business and Design in RostockWarnemünde, Germany, is involved in both parts of ship operation the navigational and technical systems. - The ship-engineering department at HSW is responsible for the analysis and conceptual redesign of current engine-related tasks as well as for repair and maintenance optimisation for unmanned operation during the sea passage. The Institute for Innovative Ship Simulation and Maritime Systems (ISSIMS) at HSW develops a simulation augmented manoeuvring support systems for remote-controlled navigation in near coastal waters. The Maritime Training Centre Warnemünde at HSW serves with its simulation environment and partner's prototype integration for the feasibility study within the proof of concept. The main idea behind the MUNIN concept is the autonomous sea passage of an unmanned vessel. Nevertheless, before the ship can be set to autonomous operation it has to put out at sea in the traditional way with a crew on board. For the unmanned voyage part the vessel is monitored by a Shore-Control Centre. When in autonomous mode, the vessel solves appearing problems with regard to weather and traffic situation by autonomous algorithms and follows its pre-defined voyage plan. If necessary, the operator takes over automatic control by commanding the vessels true heading and speed-over-ground. Furthermore, when exact manoeuvring is required, the operator enables a mock-up bridge to manually control the vessels manoeuvring systems like rudder and engine from a situation room within the Shore-Control Centre. Assuming that the connection fails, the vessel has to drift or, if possible, drop the anchor to maintain its position. 72.1. Remote Manoeuvring Support System-On-line Prediction and presentation of operational limits The Remote Manoeuvring Support System envisages the improvement of the mental model of experienced ship officers on board sea-going vessels to a Shore-Control Centre. Since for the shore-based operators the feeling of the ship's motion is missing, a way must be found to transmit the impression and feeling of the ship's actual and future motion to the operators. The problem is: there is no scope for the conventional "trial and error corrections" or "touch and feel experiences" for vessels fully controlled by shore-side operators. The remote manoeuvring support system's aim is to allow safe and efficient remote-controlled navigation in near-coastal waters. The innovative value of the Fast-Time Simulation technology is the look-ahead function of ship's motion by dynamicprediction methods, so that a ship's officer or shoreside operator can foresee the vessels future path. The Remote Manoeuvring Support System prototype contains three different modules - all based on Fast-Time Simulation und dynamicprediction methods: Monitoring tool with visualisation of future ship track by means of dynamic-prediction methods Pre-planning tool to design safe and efficient manoeuvre plans for the upcoming manoeuvring Prediction of the operational limits visualising the required room to manoeuvre. Not only for collision avoidance but also for navigation in narrow waters it is from high importance for a shore-side operator to know the operational limits of the vessels under his surveillance. The problem is that the manoeuvrability depends on many hard-to-estimate factors. High speed in shallow water e.g. causes squat effects, and the speed-through-the-water to speed-over-ground ratio increases/decreases rudder effectiveness as well as waves and gales affect the turning and stopping behaviour. The mariner aboard senses this and directly interprets the effect by the above named factors. He can feel and observe a squat effect way easier as an operator sitting in a control centre ashore in front his screens. He has trained his mental model of ship's motion by years of experience at sea. To support the shore based operator by information on ship's motion dynamics, the Remote Manoeuvring Support System supplies the operator (and the collision avoidance system on board) with vessel data regarding its operational manoeuvring limits. Figure 9. Sample for presentation of dynamic-manoeuvring prediction of actual manoeuvring track (black-dotted contours) and additional manoeuvring tracks for hard-to-STB (green) and PT (red) as well as for crash stop (black) from actual motion parameters - the ship has applied rudder amidships the contours of actual control are ahead of the ships position Figure 9 shows the monitoring concept with the prediction of the manoeuvring limits. All four manoeuvre predictions will be supplied in a https://www.w3.org/1998/Math/MathML"> 1 H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> update rate. This figure shows a situation for a collision threat: the own ship is the stand-on vessel and the ship on its port side is expected to do a course change to avoid a collision according to COLREG rule 15 . In case the ship as not acting in proper time, the own ship is obliged to do an evasive manoeuvre according to COLREG rule 17 . From the figure it is to be seen that a stopping manoeuvre would not help anymore but a turning circle to starboard would help. 10:00:40 Start of prediction from 10:0030 10:00:40 Position for potential control measures Figure 10 . Sample for explanation of the effect of time delay in ship-shore-communication and the ad-vantage of prediction for filtering and remote manoeuvring at time point 10:00:30 The most important support is necessary if there is a time delay in the communication between the autonomous ship and the shore control centre during the remote manoeuvring status: in Fig. 13 a sample is given for explanation of the effect of time delay in ship-shore communication and the advantage of prediction for filtering and remote manoeuvring action by the shore-based controller. The message for the measured position was received at 10:00:30 with time delay of https://www.w3.org/1998/Math/MathML"> 10 s e c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , i.e. the message was sent 10:00:20. This position was filtered (yellow star, as for the previous measured positions before). From this filtered position the current position was calculated by prediction on the Predicted track (blue broken line) with control settings from 10:00:20. In the same way the position at 10:00:30 was found which the initial point for the new prediction is. From the assumed/ predicted position at 10:00:30 the new prediction for new settings from 10:00:30 will take effect after another delay of https://www.w3.org/1998/Math/MathML"> 10 s e c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at the position at 10:00:40 - from there the red dotted contours and track are shown for the new predicted track. It is obvious that it is very difficult to steer the ship if the time delay is increasing. Within the project it is planned to do some investigations into the maximum delay allowed to secure a safe control of the vessel from shore. 1. ACKNOWLEDGEMENTS The research results presented in this paper were partly achieved in research projects "ADvanced Plan-ning for OPTimised Conduction of Coordinated MANoeuvres in Emergency Situations" (ADOPTMAN), COSINUS and Maritime Unmanned Navigation through Intelligence in Networks (MUNIN) funded by EU, by the German Federal Ministry of Economics and Technology (BMWi), Education and Research (BMBF), surveyed by Research Centre Juelich PTJ and DLR. Additionally it has to be mentioned that the professional version of the SAMMON software tools has been further developed by the start-up company Innovative Ship Simulation and Maritime Systems GmbH (ISSIMS GmbH; www.issimsgmbh.com). 2. REFERENCES Benedict, K., Baldauf, M., Felsenstein, C., Kirchhoff, M.: “ Computer-based support for the evaluation of ship handling simulator exercise results" MARSIM - International Conference on Marine Simulation and Ship Manoeuvrability, Kanazawa, Japan, August 25 th https://www.w3.org/1998/Math/MathML"> - 28 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> th 2003 Benedict, K., Baldauf, M., Kirchhoff, M., Koepnick, W., Eyrich, R. 2006: Combining Fast-Time Simulation and Automatic Assessment for Tuning Simulator Ship Models. MARSIM - International Conference on Marine Simulation and Ship Manoeuvrability, Terschelling, Netherlands, June 25-30 2006. Proceedings, M-Paper 19 p. 1-9 Benedict, K.; Kirchhoff, M.; Gluch, M.; Fischer, S;; Baldauf, M. 2009: Manoeuvring Simulation on the Bridge for Predicting Motion of Real Ships and as Training Tool in Ship Handling Simulators. TransNav - the International Journal on Marine Navigation and Safety of Sea Transportation, Vol. 3 No. 1 - March 2009. Benedict, K.; Kirchhoff, M.; Gluch, M.; Fischer, S.; Baldauf, M. 2013: Simulation Augmented Manoeuvring Design and Monitoring - a New Method for Advanced Ship Handling. TransNav - the International Journal on Marine Navigation and Safety of Sea Transportation, Vol. 3 No. 1 - May 2013. Benedict, K.; Baldauf, M.; Fischer, S.; Gluch, M.; Kirchhoff, M.; Schaub, M.; M.; Klaes, S. 2012: Fast Time Manoeuvring Simulation as Decision Support for Planning and Monitoring of Ship Handling Processes for Ship Operation On-Board and Training in Simulators. MARSIM - International Conference on Marine Simulation and Ship Manoeuvrability, Singapore, 23 -27 April 2012. Fischer, S., Benedict, K. 2009: "Analyses of manoeuvring procedures on ferry Mecklenburg-Vorpommern in Rostock Sea Port and potential improvements using alternative manoeuvring concepts with Dynamic Predictor" Internal research report (in German only), Hochschule Wismar, Dept. of Maritime Studies, Warnemuende ISSIMS GmbH 2012: Web page for SIMOPT & SIMDAT: https://www.issims-gmbh.com/joomla/index.php/softwareproducts Benedict, K.; Baldauf, M.; Fischer, S.; Gluch, M.; Kirchhoff, M.; Schaub, M.; M.; Klaes, S.: APPLICATION OF FAST TIME MANOEUVRING SIMULATION FOR SHIP HANDLING IN SIMULATOR TRAINING AND ONBOARD. Proceedings of INSLC 17. Sept 2014 at Hochschule Wismar, Rostock Warnemuende / Germany. Hederstrom, Hans: MOVING FROM RANK TO FUNCTION BASED BRIDGE ORGANISATION. Proceedings of INSLC 17. Sept 2014 at Hochschule Wismar - Rostock Warnemuende / Germany 3D Navigator Decision Support System Using the Smartglasses A. Łebkowski Gdynia Maritime University, Poland Abstract The publication contains a proposal to use SMARTGLASSES technology as part of a 3D Decision Support System for Navigators (3DSSN). Information presented by the system is a fusion of normal navigator's vision from the bridge with the information presented in 3D technology using the Smartglasses. By using this technique it is possible for instance to steer the ship in conditions of limited visibility, or to select an optimal collision avoidance maneuver or route of passage. 3. INTRODUCTION Seas and oceans surrounding the land were always inseparable part of mankind's history - they provided food, new land and allowed trade. On the other hand they were always dangerous and mysterious element, impossible to tame. The first basic problem was the difficulty in determination of ship's position. Navigators of the past were not always sure where they were headed and what was the destination port heading. One moment of inattention was enough to experience how sinister and hazardous the sea was. Treacherous tides, varying hydro meteorological conditions, maelstroms, shallows were very serious navigational obstacles that weighted on life and safety of transported goods. Over time, additional navigational hazards appeared. Following the growing number of traveling ships, their size and velocity also increased. No nation could grow without advancement in navigational and transportation technology. Looking back in time, the biggest empires of their age built their might on their fleet - like the British Empire, which was controlling one quarter of land on whole Earth. We admire Scandinavian sailors' accomplishments - the Vikings, who as first Europeans set feet on America's shore. Scientific progress including astronavigation techniques using Sun's and stars' positions allowed them to explore high seas. Hungarian scientists have researched the theory of application of "sun stones" - natural polaroid filters in form of Calcite, Tourmaline and Mica minerals, which change their brightness and color depending on incident light angle. Usage of sun stones allowed the Vikings to ascertain their position regardless the atmospheric conditions. [1]. It is also known, that astronomical and geographical knowledge of Nordic people was many years ahead of their time. Awareness of Earth's sphericity and related terms such as longitude, latitude, arctic circle or the equator are among the examples. The exact system created and used by Viking people remains a mystery, however [9]. During the ages, the secrets of navigation were constantly evolved, and even today this process continues. Calculation of location using satellite based techniques is certainly not the limit of our capabilities, as the progress in this matter is constant. Many new technologies take inspiration from the antiquity. Take for example the mythical Talos - a colossus forged out of bronze by the Hephaestus. It guarded Crete's shores and denied access to any foe. Having noticed an unidentified ship or other object on the sea, it heated up to cherry red glow and burned them in its fiery embrace. Legends of ignition and destruction of foreign objects were not uncommon in that era, however the historians' attention was attracted by one difference between Talos and other entities: what enabled him to identify friend from foe? This could be and a system of artificial reasoning and decision - a first artificial intelligence system. It could be said that Talos was the first robot. The issues of navigation and artificial intelligence are interconnected. Currently there are more and more systems developed using these techniques to make navigation safer, by helping foresee eventual occurrence of threats. Moreover, they possess a capability for self-learning, a feature recently reserved only to living organisms. Contemporary science implements many solutions based on artificial intelligence. Agent systems, evolutionary algorithms, neural networks, fuzzy logic or expert systems are among the best known methods of AI used in navigation systems. Listed methods are part of the e-Navigation strategy being currently developed by IMO. It can be described as a harmonized collection, integration, exchange, presentation and analysis of marine information on board and ashore by electronic means to enhance berth to berth navigation and related services for safety and security at sea and protection of the marine environment [10]. The obvious cause of this is a green light for development of new navigator decision support systems, such as one proposed by the author, which combines use of information available from ECDIS with new technical possibilities offered by Smartglasses technology (Figure 1) [19]. Although current IMO regulatio Although current IMO regulations forbid the sailing of unmanned ships, doubtlessly the next step in ship construction will be development of such ships, capable of sailing without their crew present. Unmanned cargo ships - drone ships, controlled remotely via satellite link from a shore station are a near future. Preliminary designs of such ships are already proposed by Rolls-Royce (Figure 2) [13] and other designers also present models of their autonomous vessels https://www.w3.org/1998/Math/MathML"> [ 8,14,15,16 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Current IMO regulations do not allow presence, let alone proliferation of full-size autonomous, unmanned vessels in maritime traffic, however it is unknown what the final shape of e-Navigation strategy will be, as the proceedings will not be finished until 2019 . Before we enter the phase of operation of unmanned ships, there will be a period of development of various technologies and systems supporting the navigator's decisions https://www.w3.org/1998/Math/MathML"> [ 3,4 , 5,6 , 7,8 , 11 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Figure 2. Views of proposed unmaned crafts [17]. These systems will undoubtedly increase the safety level on sea. They greatly reduce the time needed by the navigator to take an optimal decision given the navigational circumstances, they help by providing information on the situation around the ship as well as data on the ship itself. In 2010 researchers from Japan Institute of Navigation presented a system which displays data and information needed for safe navigation directly on the bridge windows [2]. Application of similar technology is proposed by scientists from RollsRoyce and VTT in their visionary project presented in 2014 , its tinal effects should be avalable around 2025. [12]. The project assumes displaying on the bridge's windows of all the data required for navigation. Information is to be additionally presented in 3D mode, which would make it more legible and comprehensible to the navigators. The following publication is author's proposition of navigator decision support system using 3D Smartglasses technology. 4. DECISION SUPPORT SYSTEMS Taking into account the number of collisions and accidents happening on sea each year, no matter what hydro meteorological conditions and water type, more and more advanced decision support systems are being used. Navigator commanding the cargo ship is required to constantly observe the dynamically forming navigational situation around his ship. Apart from that, he needs to pay attention to various instruments and devices which constantly flood him with information. Based on observations and readouts from auxiliary devices, in case of collision hazard he is required to designate an anticollision maneuver in the shortest time possible. In such stressful situation, where single man has to make a quick and precise decision it is easy to make a mistake. An important matter from the point of cruise safety is the time between arising of collision situation and commanding an anti-collision maneuver. The shorter the time, the bigger the margin of error for navigator's eventual mistake. So given the long enough decision time, the navigator has opportunity to correct any eventual errors. Application of decision support system allows shortening of time between noticing a danger and issuing a command which neutralizes it. Apart from classic decision support systems, which mostly use the displays of existing systems or put additional ones, such as: Navigational Intension Exchange Support System (Passing Pattern); INT-NAV (Integrated Navigational System. Tracked Target Information and Video display); Collision Threat (Scheduled route based collision danger area display. Scheduled route and collision danger zone); Collision Avoidance (Display for automatic collision avoidance system - recommended collision avoidance route); NAVIEYE (Vessel surveillance equipment. Video image of target ship); Route Suggestion (Route suggestion from Shore to Ship); NAVDEC https://www.w3.org/1998/Math/MathML"> [ 11,18 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and many others, there are systems which strive to dimensionally present parameters for given navigational situation. One of such systems is Visual Lookout Support System proposed in 2009 by researchers from Japan Institute of Navigation. A team led by Kenjiro HIKIDA has implemented a solution which displays navigational parameters on transparent head-up display placed in the field of view of navigator standing on the bridge (Figure 3) [2]. View through the window with VLSS installed [2] The system displays basic information on HeadUp Display such as object's name, bearing, range, experiments have shown that system's application experiments have shown that system's application navigational situation when using radar system navigational situation when using radar system display. Using VLCC, navigator can save 2 to 10 seconds only on interpretation time. Therefore the correct manner of presenting the data can influence the delay before issuing anti-collision maneuver. Another solution could the system presented by Rolls-Royce and VTT [12,13]. It assumes displaying of necessary information on specially crafted bridge window, including parameters of passing objects, data on hydro meteorological conditions, digital maps projection or showing the distance to nearby objects. Some of the information provided can be displayed three-dimensionally. Project of the future bridge is shown in Figure 4 . Figure 4. The concept of the navigation bridge by Rolls-Royce and VTT [17]. 5. TECHNOLOGY First Smartglasses models [19] had integrated Optical Head Mounted Displays (OHMD) or transparent Heads-Up Displays (HUD). Next generations had transparent pieces allowing the user to see projections of virtual video (Augmented Reality - AR) with possibility of https://www.w3.org/1998/Math/MathML"> 3 D https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> elements display. Using Smartglasses technology, which combines a function of glasses with display and a computer, all in one package, it will be possible to present navigation parameters and display of navigational situation around on ship. State of the art Smartglasses, as proposed in this article, have extended functions of data processing, like in smartphones and tablet computers. (Figure 5 ). Figure 5. View of META Smartglasses [20]. Navigation between applications can be realized using navigator's voice or with his hands. Pointing at any element, the navigator will have possibility to select various display modes and parameters. Using "pinching" and "spreading" in the air it will be possible to mark objects or browse through their parameters essential from the point of navigation. Additionally, modern Smartglasses can launch mobile applications, recognize and interpret objects in environment. They also have built-in components like multiaxial accelerometers, gyros, Bluetooth, Wi-Fi and GPS modules. They will allow the navigator to pan and tilt his head and observe through transparent displays virtual holograms of other objects, his ship route, other ships routes, potential crossing or approach points or other information such as boundaries of allowed navigation areas, actual meteo condition messages and important messages from VTS station or AIS system with satellite modules. Figure 6. Example view through Smartglasses. An ideal set for the navigator on a cargo ship's bridge would be a combination of Smartglasses technology with land CCTV and VTS systems and onboard CCTV system (equipped with infrared and thermal cameras). 6. SYSTEM STRUCTURE The constant drive to make sailing better, raise the efficiency of transportation services and provide for crew and transported cargo safety is the reason for installation of modern anti-collision devices and systems on ships of all types. Presence of these systems not only gives the awareness of increased safety, but also increases the efficiency of vessel motion from source to destination ports. These systems realize informational and computational functions as well as they provide warnings and alarming in case of dangerous situations with probable grim consequences to both crew and environment. THE DATABASE OF NAVIGATION INFORATION (ECDiS) Figure 7. The structure of 3D Navigator Decision Support System using the Smartglasses Technology. In Figure 7 a structure of https://www.w3.org/1998/Math/MathML"> 3 D https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Decision Support System for Navigators is shown. The definition of "System" includes a set of some elements, isolated from their neighborhood as a relatively autonomous entity, whose elements possess internal connections and feedbacks. All the elements work together, towards common goal. In this case, the goal is to safely navigate a ship. Therefore system is an organized object, acting in a defined environment and consisting of smaller elements called subsystems. Sub-systems are systems within greater system, which are a part of cooperative relationships so that each can realize the main goal and can contribute to common success. System is also called a set of elements connected into common dependencies, created to fulfill certain goals. Summing up all these statements it can be said, that a system is a set of interconnected elements, which operate as a unity and have a single goal, which they constantly seek. Modern anti-collision systems allows precise tracking of even up to 300 various dynamic objects. Similarly, the goals for 3D Decision Support System for Navigators will include: indication of safe space for ship navigation or determination of ship route (fairways, ice fields, passage over shallows, harbor approach zones, navigation exclusion zones), - detection and tracking of objects potentially dangerous to own ship, indication and display of parameters (bearing, range, heading, speed, CPA, TCPA) of objects being tracked and indicated by the navigator, alarming in the condition of possible collision, indication of collision parameters for dangerous and indicated by navigator objects (CPA, TCPA), graphical imaging of relative and absolute motion of tracked objects, signaling in the event of rapid change in course or speed of tracked objects, decision support on safe maneuvers including suggested course and speed in order to maintain safe distance from passed objects, presentation of data on parameters of passed objects (mostly AIS data: name, call sign, ship type, size, etc.), presentation of data on hydro meteorological conditions (weather forecast, present weather on given waters, etc.), graphical simulation of trial anti-collision maneuver along with projected consequences. https://www.w3.org/1998/Math/MathML"> 3 D S S N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in its structure relies mainly on data collected prior by ECDIS, which include data from: https://www.w3.org/1998/Math/MathML"> l o g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , gyrocompass, AIS, radar system with ARPA, electronic map, satellite navigation system and additional systems such as: NavTex, local Meteorological system, NOAA, NWS, NOS and others. Moreover, 3DSSN can interoperate with other decision support systems which could calculate, based on information available to them, the optimal ship route https://www.w3.org/1998/Math/MathML"> [ 3,4 , 5,6 , 7,8 , 18 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Thanks to its capabilities, 3DSSN can be used almost on any ship. System properties allow it to be used during passage through regions of limited visibility, regions where sea bottom raises dangerously and constitutes a danger to the ship, or in regions with possibility of icebergs presence. 7. CONCLUSIONS Application of 3D Decision Support System for Navigators could greatly increase the safety level on sea. Due to possibilities of holographically presentation of calculation results and decision support could be a powerful tool for navigational data implementation by the navigator. Thanks to presentation of navigational situation by 3D holograms and digital markers it is possible to plot passage routed as well as other traffic parameters for both the own vessel, and other vessels present in the vicinity. It allows the navigator to know well in advance the other ships navigators' desired maneuvers and avoid collision. - The system appears to be much cheaper both to purchase and to operate than the presently proposed and developed 3D display systems https://www.w3.org/1998/Math/MathML"> [ 2,12,13 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Its simple construction and low cost could make it find lots of users in the near future. The only limit in application of this system seems to be the imagination of designers of displayed data. 3DSSN could be used on many ship types, its practical applications pretty unlimited. It could be used for example by: navigators during adverse weather conditions, harbor pilots, and (after software upgrade) by other maritime workers such as platform crew, mechanics, electricians or deck crew. In the near future, a prototype will be constructed and its usefulness will be evaluated on training ships. An interesting solution would be an application of Smartglasses technology on submarine vessels. 8. REFERENCES [1] Bernáth B., Farkas A., Szâz D., Blahỏ M., Egri A., Barta A., Akesson S., Horvath G., How could the Viking Sun compass be used with sunstones before and after sunset? Twilight board as a new interpretation of the Uunartoq artefact fragment 10.1098/rspa.2013.0787 Published 26 March 2014. [2] HIKIDA K., Development of a Shipboard Visual Lookout Support System with Head-up Display, Navigation System Research Group, Navigation and Logistics Engineering Department, National Maritime Research Institute, CiNii 2010. [3] Lisowski J.: Optimal and game control algorithms of ship in collision situations at sea. Control and Cybernetics, No. 4, Vol. 42, 2013, p. 773-792. [4] Lisowski J.: Optimization-supported decision-making in the marine game environment. Solid State Phenomena, Trans Tech Publications, Switzerland, Vol. 210, 2014, p. 215-222. [5] Lisowski J.: Game strategies of ship in the collision situations. TransNav - The International Journal on Marine Navigation and Safety of Sea Transportation, Vol. 8, No. 1, 2014, pp. 69-77. [6] Lisowski J.: Computational intelligence methods of a safe ship control. 18th International Conference in Knowledge Based and Intelligent Information and Engineering Systems KES2014, Gdynia, Elsevier Procedia Computer Science, No 35,2014 , pp. 634-643. [7] Lebkowski A., Control of ship movement by the agent system, Polish Journal of Environmental Studies Vol.17, No. 3C, 2008 [8] Łebkowski A., Negotiations between the agent platforms. Scientific Papers of Gdynia Maritime University, Gdynia 2013. [9] Majek M., Comparative analysis of selected systems and control systems - artificial intelligence methods currently used for process control of the ship. Master's Thesis, supervisor dr inż. Andrzej Lebkowski, AMG 2013. [10]IMO, NAV 59/6. Development of an e-Navigation Strategy Implementation Plan, Report of the Correspondence Group on e-Navigation, submitted by Norway. IMO (2013). [11] https://www.e-navigation.net/index.php?page=portrayalexamples [12] https://www.vtt.fi/files/events/ITSEurope/UXUS pressrelaseFINALprintversion.pdf [13] https://www.rolls-royce.com/marine/customer_focus [14] https://www.unmanned-ship.org/munin/ [15] https://gotransat.com/ [16] https://www.wired.com/2014/10/navy-self-drivingswarmboats/ [17] https://www.flickr.com/photos/rolls-royceplc/sets/72157647334399764 [18] https://www.navdec.com [19] https://www.Smartglassesnews.org/smart-glasses/ [20] https://www.spaceglasses.com/products. Neuroevolutionary Ship Maneuvering Prediction System M. Łącki Gdynia Maritime University, Gdynia, Poland Abstract The paper presents a concept of the advanced ship maneuvering prediction system with neuroevolutionary method. This ship handling system simulates a learning process of an autonomous control unit, created with artificial neural network. This unit observes input signals and calculates the values of predicted parameters of the vessel maneuvering in confined waters. In neuroevolution such units are treated as individuals in population of artificial neural networks, which through environmental sensing and evolutionary algorithms learn to perform given task efficiently. The task is: continuous online learning and prediction of the values of a navigational parameters of the vessel after certain amount of time, regarding an influence of its environment. 9. INTRODUCTION Prediction of vessel movement during maneuvers in restricted waters is of primary meaning regarding safety of people, equipment and the environment. Increase of computational power of standard computers allow to implement complex algorithms into advanced decision support systems also in the field of marine navigation. Such a system should include the following main functions: analysis of the navigational situation online, in continuous mode, warning before the dangerous situation may take place, e.g. possible collision or exit from a particular limited area in an undesirable direction, providing transparent information that can be used in co-operation with local authorities and other auxiliary units of the area, it shall give the answers to "what if" and "when" questions, in the field of ship maneuvering actions and navigational situations. All these requirements may be obtained with neuroevolutionary methods. These methods are intensively studied and implemented in different fields of science, including robotics (Haasdijk et al., 2010 ; Lee et al., 2013), automation processes (Bagnell and Schneider, 2001; Kenneth et al., 2005 ; Zhao et al., 1995), multi-agent systems (Nowak et al., 2008), designing and diagnostic (Larkin et al., 2006) and many others. Neuroevolutionary algorithms are successful methods for optimizing neural networks topologies, especially in dynamic continuous reinforcement learning tasks. Their significant advantage over gradient-based algorithms is the capability to modify network topologies along with connection weights. The basic concept of the system is presented in figure 1 . Figure 1. Main task of advanced prediction system is to calculate a position of the vessel as accurate as possible to her final position The system shall, through continuous learning process, predict the ship position and state of the environment after specified time interval as accurate as possible in comparison to final real position of the vessel. It is possible to calculate a probable position when there is a simulation model of the vessel available. It is required that simulation model includes the equations and coefficients for wind, current and waves. But in most cases such advanced non-linear simulation model is not available. And again, a good solution for this problem is neuroevolution. 10. NEUROEVOLUTIONARY METHODS Neuroevolutionary methods are part of intelligent computing methods that are capable of finding solution of complex tasks with artificial neural networks (ANN) created with evolutionary algorithms (EA). Such combination gives an advantage of flexibility and adaptation, which allows to adjust computational structures to dynamically changing tasks. In neuroevolution ANN is treated as an individual in a population of multiple networks. Basic topologies of the initial population are randomly determined at the beginning of learning process. Each individual begins the process of finding a solution with the same starting parameters. The action of each individual is usually assessed with the reinforcement learning algorithms (Stanley et al., 2005) and evolutionary stage of the system shall select individuals best suited to the task during selection stage, which determines the whole population to improve its genetic material over time. Evolutionary stage of the system consist three main processes: selection of the best individuals, reproduction (with cross-over and mutation subprocesses), replacement (offspring replaces worst individuals). Figure 2. An example of encoded artificial newral network due to NEAT method In case of evolutionary method the genetic encoding of neural network topology is very important. Author of this paper implemented the modified NEAT method to this system (Figure 2). NEAT (NeuroEvolution of Augmenting Topologies) adjust the topology of ANN's with EA (Stanley and Risto, 2002a) gradually to given task, allows to obtain a set of ANN's that are best fitted to this task (Łącki, 2009). Each node represents a neuron that produces a real value between 0 and 1 as a result of normalized weighted sum of its inputs. Normalization of weighted sum is performed with sigmoid function, as in Equation 1. https://www.w3.org/1998/Math/MathML"> o j = 1 1 + e - s j β + θ j https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where: https://www.w3.org/1998/Math/MathML"> o j - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> output value of an neuron, https://www.w3.org/1998/Math/MathML"> S j - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> weighted sum of input values https://www.w3.org/1998/Math/MathML"> x ηj https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with weights https://www.w3.org/1998/Math/MathML"> w nj https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> β - slope coefficient, https://www.w3.org/1998/Math/MathML"> θ j - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bias. Adding the bias signal of constant value 1, allows to shift the output value of the activation function (Figure 3). Influence of bias may be adjusted through changing weight of this signal, when the mutation stage is performed in evolutionary process during creation of an offspring in the reproduction stage. Figure 3 . Influence of bias coefficient https://www.w3.org/1998/Math/MathML"> θ j https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to value of sigmoid function In this stage two best neural networks are chosen and its genetic material is crossed-over to create two new individuals. Cross-over of disparate topologies is processed in a meaningful way by pairing up genes with the same historical markings, called innovation numbers. With this approach the offspring may be formed in one of three ways: In uniform crossover, matching genes are randomly chosen for the offspring genome, with higher probability for better fitted parent. In blended crossover, the connection weights of matching genes are averaged. In elite crossover disjoints and excesses are taken from more fit parent only, all redundant genes from less fit parent are discarded. All matching genes are averaged. Genes that do not match with the range of the other parent's innovation numbers are called disjoints (when they occur within the genome) or excesses (when they occur outside of the genome) These three types of crossover were found to be most effective in neuroevolutionary algorithms in comparison to other crossover methods (Stanley and Risto, 2002b). Genes that have been disabled in previous generations have a small chance of being re-enabled during new offspring creation, allowing ANNs to make use of older solutions once again (Lącki, 2012). Evolutionary neural network can keep historic trails of the origin of every gene in the population, allowing matching genes to be found and identified even in different genome structures. Old behaviors encoded in the pre-existing network structure have a chance to not to be destroyed and pass their properties through evolution to the new structures, thus provide an opportunity to elaborate on these original behaviors. The number of inputs and outputs is fixed. During evolution, in mutation stage, the number of internal neurons and connections may change. In classic NEAT method the number of nodes and connections may only increase over time, with possibility to temporary disable the connection. This guaranties to transfer learning experience from ancestors to new offspring and fast learning of new tasks for new population but it may be disadvantageous in such dynamic environments as ship maneuvering in restricted waters. In this case an experience of old population may be insufficient and its learning ability to slow, due to size of experienced ANN's. Through mutation, the genomes in modified NEAT will gradually get larger for complex tasks and lower their size in simpler ones. Genomes of varying sizes will result, sometimes with different connections at the same positions. Historical markings represented by innovation numbers allow neuroevolutionary algorithm to perform crossover operation without analyzing topologies. Genomes of different organizations and sizes stay compatible throughout evolution, and the variable-length genome problem is essentially solved. This procedure allows for used method to increase complexity of the structure while different networks still remain compatible. During elite selection process the system eliminates the lowest performing members of every specialized group of individuals from the population. In the next step the offspring replaces eliminated worst individuals. Thus the quantity of the population remains the same while its quality shall improve according to assumed goals and restrictions of the task. 11. INPUTS AND OUTPUTS OF ANN'S Input and output signals of ANN's must be determined at the beginning of designing phase of the system. Proper set of signals considered in the model is crucial for efficient performance of the system and for its fidelity and accuracy in comparison to the real navigational situation. Input signals in the system, with three degrees of freedom vessel movement, are as follows: Ships' course over ground, Ships' angular velocity, Ships' speed over ground, Ships' position, Angle and velocity of a current, Angle and velocity of a wind. Main propeller revolutions (current and preset), Rudders' angle (current and preset). In future research other signals from environment may be taken into account, i.e. waves, cargo, trim and roll. Output signals of ANNs shall generate the values for important parameters that may change after certain amount of time. Most important signals in prediction process are: Ships' position, Ships' course over ground, Ships' speed over ground, Ships' angular velocity All of the input and output signals are encoded as real values between 0 and 1 . Computational flexibility and ability to adapt a network topology to a given task allows to design complex sets of inputs and outputs of ANN's. Since the neural network with multiple outputs learns slower than one with only one output, the proposal of the author is to divide a population of ANNs into different specialized groups of networks, designed to calculate a predicted value of a single particular output signal (Figure 4). This is a very sophisticated neuroevolution method that can deal with premature convergence that preserves diversity and gradual complexity of explored solutions. Speed over ground Angular velócity Figure 4 Each group has separate ranking list and individuals compete only within their own group. This approach requires much more memory allocation for higher amount of genetic material. Performance of each individual is measured in predicted time interval and its fitness value is calculated as a difference between real and predicted value (Formula 2 ). https://www.w3.org/1998/Math/MathML"> f i = r n - p i 2 ← https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> min where: https://www.w3.org/1998/Math/MathML"> f i https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - fitness value of an individual i (a cost criteria), https://www.w3.org/1998/Math/MathML"> r n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - real value of a signal of n-group, https://www.w3.org/1998/Math/MathML"> p i - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> predicted value of a signal of an individual i. In this case the individuals with least fitness value are more likely to reproduce their genetic material in next generation. General algorithm for prediction system is presented on figure 5 . Figure 5. General algorithm of prediction system with neuroevolutionary method Input signals have been divided into two groups environmental and steering signals. Group of environmental signals consist all data incoming from vessels surroundings (i.e. winds and currents speed and direction) which creates an input state vector for the system. Implementation of mathematical model of wind to the motion control in neuroevolutionary prediction system increases its performance and robustness in simulated environment. Under pressure of wind force, depending of the ships' design (location of the superstructure, the deployment of on-board equipment and cargo, etc.) she tends to deviate from the course, with the wind or into the wind. The smaller the speed and draft of the ship, the greater the influence of wind. Of course, the size of the side surface exposed to wind is essential to the ships movement. When the ship moves forward the center of effort of the wind (wind point, WP) is generally close to amidships, away from pivot point (PP). This difference creates a substantial turning lever between PP and WP, thus making the ship, with the superstructure deployment at stern, to swing the bow into the wind. For ship moving forward there are defined terms of relative wind speed https://www.w3.org/1998/Math/MathML"> V nw https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and angle of attack https://www.w3.org/1998/Math/MathML"> γ rw https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Isherwood, 1973). Wind forces acting on symmetrical ship are in general calculated from data as ship's overall length, surfaces affected by the wind, air density and coefficients calculated from available characteristics of ships model, i.e. from wind loads data of Oil Companies International Marine Forum (OCIMF, 1977). This organization identifies safety and environmental issues facing oil tankers, barges, terminals and offshore marine operations, and develops and publishes recommended standards that will serve as technical benchmarks for regional and worldwide exploitation. Additional forces that affect ships movement are water flows from current and tides. In this case the water moves in relation to the bottom of a river, sea or an ocean. Position of the Moon and the Sun in relation to the Earth affects mostly waters in the oceans. Many naval ports of the world have their locations at a river estuaries. Currents of that rivers may be often affected by ocean tides. Tidal force is determined by the difference in forces at the Earth's center and surface. Tidal forces are mostly available from local authorities if a form of timetable sets and charts. Tidal charts are grouped in sets, each set covers the time interval between two consecutive high tides in the area. These charts they give the average tidal flow information for desired time span for the ship maneuvering area. Information on a tidal chart consists of direction and average flow speed in knots for specified tides. An alternative to the tidal charts is the tidal diamonds method, which may be found on most nautical charts. With this method one can relate certain points on the chart to a table that will calculate the direction and velocity of tidal flow and according to this flow the estimated position of the vessel can be calculated regarding the direction of the tide. The gravitational tides are not the only one affecting flow of the water, there are also terrestrial tides, atmospheric tides and thermal tides. Atmospheric tides are caused by the radical effects of weather and solar thermal tides and in most cases they reinforce oceanic tides. Under the pressure of a current a ship is drifting together with the water, relative to the ground and any fixed objects. When the ship is moving in current the speed over ground is resultant velocity of ship speed and velocity of the current. Stronger water flows may cause the tendency to swing the ship with the stern or bow towards the side, which may lead to dangerous situation. This might be particularly difficult to overcome when working in following tide because of the small effectiveness of the rudder at low speed. Steering signals consist data that may be changed by a user of the system (i.e. a navigator or a commander on the bridge). Steering signals include propellers revolutions or thrust and rudders angles. All these input signals affect ship's movement which creates a new state of the environment with the moving vessel in it. At the same time the similar new state parameters are being calculated in the neuroevolutionary system, regarding the same input signals. The real and predicted values are compared and the result of comparison provides substantial information for the system that allows to elaborate the quality of created ANN's and overall performance of whole population. During evaluation the ranking of ANNs it created and the best networks are stored for future exploitation. 12. SIMULATION MODELS AND RESULTS For the purpose of a ship movement simulation an application has been created by the author (Figure 6). Figure 6. An applicationmodels of different vessels The designed application allows to choose ppecific model of the vessel, to set a starting parameters of navigational situation in restricted waters, including speed and direction of a wind and a water current, and run a simulation with partially observable prediction values that can be saved to a file and analyzed after the simulation. Two simulation models of ships with threedegrees-of-freedom had been used in the system for the purpose of systems performance test. Main parameters of ships has been compared in table 1. Table 1. Main parameters of simulation ship models. Name Blue Lady Cape Norman Type VLCC Container ship Scale 1:24 1:1 Length https://www.w3.org/1998/Math/MathML"> 13,78 [ m ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 175 [ m ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Beam https://www.w3.org/1998/Math/MathML"> 2,38 [ m ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 26,5 [ m ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Draft https://www.w3.org/1998/Math/MathML"> 0,86 [ m ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 14,2 [ m ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Capacity/Tonnage https://www.w3.org/1998/Math/MathML"> 22,83 [ T ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 1504 [ T E U ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Max. speed https://www.w3.org/1998/Math/MathML"> 3,1 [ k n ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 20,4 [ k n ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The sets of output data of ANN's has been calculated and recorded during task evaluation in every generation as the results of simulation. The population consist four separate groups of ANNs, with 50 individuals each, resulting in 200 ANNs in total. groups of ANNs for 200 generations (Figure 7). Since there is always only one ontimal solution for every parameter in the prediction system, the algorithm tends to converge prediction system, the algorithm tends to converge quickly to this solution. These simulation results single output neural network. For two different models of the vessels the average fitness values become at stable levels after about 20-40 generations, which took about few minutes of simulation on a standard PC. Spread of average fitness for speed over ground is greater for container ship, regarding its greater range of possible predicted speed values. 13. REMARKS Intelligent maneuvering prediction system for maritime transport has some valuable benefits: increases of the safety of navigation in a restricted water area by improving the data analysis for decision-maker during maneuvers, improvement of the operation of ships in port, due to the increased bandwidth, reduction of operating costs of vessels, minimization of the occurrence of human errors, reduction of the harmful impact of transport on the environment. It is important to notice that all these benefits strictly depend on proper adjustment of evolutionary parameters, the size of ANNs population and the encoding methods of signals considered in serviced environment. Neuroevolutionary approach to ship handling in confined waters improves a quality of maneuvers and safety of navigation effectively (Łacki, 2008). For the simulation study, mathematical model of three-degrees-of-freedom maneuvering VLCC tank ship with the single-propeller and single-rudder was applied to test the prediction performance of the system. Artificial neural networks based on modified NEAT method increase complexity and performance of considered model of ship maneuvering in confined waters. Implementation of additional input signals related to influence of wind and current allows to simulate complex behavior of the vessel (Lącki, 2012) in the environment with much larger state space than it was possible in a classic state machine learning algorithms (Lącki, 2007). Promising simulation results of maneuvers in variable wind and current conditions of different ship models encourage to further research of the neuroevolutionary methods which may finally be implemented into advanced navigational prediction systems to increase the safety of navigation. 14. REFERENCES Bagnell, D. & Schneider, J. 2001. Autonomous helicopter control using reinforcement learning policy search methods. Haasdijk, E., Rusu, A.A. & Eiben, A.E. 2010. HyperNEAT for Locomotion Control in Modular Robots. Isherwood, J.W. 1973. Transactions of Royal Institution on Naval Architects, Wind resistance of merchant ships, vol. 115,327-332 Kenneth, S., Nate, K., Rini, S. & Risto, M. 2005. Neuroevolution of an automobile crash warning system , Washington DC, USA. Larkin, D., Kinane, A. & O'Connor, N. 2006. Towards hardware acceleration of neuroevolution for multimedia processing applications on mobile devices, Hong Kong, China. Lee, S., Yosinski, J., Glette, K., Lipson, H. & Clune J 2013. Applications of Evolutionary Computing, Evolving gaits for physical robots with the HyperNEAT generative encoding: the benefits of simulation. Lącki, M. 2007, Machine Learning Algorithms in Decision Making Support in Ship Handling., Katowice-Ustron, WKE. Eącki, M. 2008. Neuroevolutionary approach towards ship handling., Katowice-Ustron, WKE. Eącki, M. 2009. Ewolucyjne sieci NEAT w sterowaniu statkiem. Inżynieria Wiedzy i Systemy Ekspertowe, Warszawa: Akademicka Oficyna Wydawnicza EXIT, pp. 535-544. Łącki, M. 2012. TransNav - International Journal on Marine Navigation and Safety of Sea Transportation, Neuroevolutionary Ship Handling System in a Windy Environment, vol. 6 . Nowak, A., Praczyk, T. & Szymak, P. 2008. Zeszyty Naukowe Akademii Marynarki Wojennej, Multi-agent system of autonomous underwater vehicles - preliminary report, vol. 4, 99-108. OCIMF 1977. Prediction of Wind and Current Loads on VLCCs, Oil Companies International Marine Forum. Stanley, K.O. & Risto, M. 2002a. Efficient evolution of neural network topologies. Stanley, K.O. & Risto, M. 2002b. Efficient Reinforcement Learning Through Evolving Neural Network Topologies. Stanley, K.O., Bryant, B.D. & Risto, M. 2005. IEEE Transaction on Evolutionary Computing, Real-time neuroevolution in the NERO video game, vol. 9, 653-668. Zhao, J., Price, W.G. & Wilson, P.A. 1995. Automatic collision avoidance: towards the 21st century. Information and Communication Technologies in the Area with A. Kuśmińska-Fijałkowska & Z. Eukasik University of Technology and Humanities in Radom, Poland Abstract Typically, communication systems in land terminals are selected without a detailed analysis of the specificity of transmission within that object. As a result, due to noise and various constraints, this system usually does not work properly. In order to avoid this, the authors of this article proposed a DECT wireless telephone system. As a result, as the standard architecture of the system was analyzed, attention was paid to the parameters that should be considered when choosing this type of systems in order to provide continuous connectivity in a complex spatial structure. 15. INTRODUCTION Reloading terminals in transport chains provide space, equipment and environment ready to translocate the units of intermodal transport between various transport connections. (Brill J., Eukasik Z. 2014; Kozyra J. 2009; Kisilowski J., Krzyszkowski A. 2014). Therefore, there is a need to implement a system of Information and Communication Technologies (ICT) which will enable to increase effectiveness of functioning of a reloading terminal in the chains of intermodal transport. Applied systems of a communication in the reloading terminals are chosen without detailed analysis, specificity of transmission within such structure.(Craven P., Wong R., Fedora N. 2013; Eugen R., Serban R., Augustin R. M. 2014; Zhu Bo O., Chen K., Jia N. 2014) They are usually shortwave transmitters. As a result, due to interferences and various limitations, this system usually doesn't work properly. (Van Vorst D. G.; Yedlin Matthew J.; Virieux J. 2014) As a result of analysis of available systems, a DECT system can best fulfil given requirements in the areas with a complex spatial structure, in which parameters relevant for a specific reloading terminal were taken into consideration. (Kuśminska-Fijalkowska A. Lukasik Z. 2009; Li T., Wang X., Zheng Ch. 2014)We should consider many aspects concerning a DECT standard, which is proposed by the authors. Firstly, standard structure of a DECT system must be precisely analysed. 16. DIGITAL ENHANCED CORDLESS System of digital enhanced cordless telecommunication DECT was designed to integrate different technologies of data transfer. With an application of appropriate devices, DECT systems enable integration with networks GSM, WLAN, ISDN and X.25 (Tuttlebee W.H.W. 1996). Apart from standard voice transmission, data transmission between various subscribers with a binary flowability to https://www.w3.org/1998/Math/MathML"> 384 k b i / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is also possible. (Jackowski S. 2005). Therefore, this system can be applied in the areas with a complex spatial structure - land reloading terminal. System DECT consists of FP (Fixed Part) and some portable parts (PP) performing a role of transmitters and receivers of information. FP consists of one central element CCFP (Central Control Fixed Part) performing control functions, for example, commutations and a certain number of the so-called RFPs (Radio Fixed Part) grouped in the so-called clusters. Each RFP is equipped with groups of radio transceivers, using one antennal system creates an individual cell. (Jackowski S. 2005). PP connect with RFP. (Fig. 1) Two or more RFPs is connected with CCFP. Access to external networks is realized through Interworking Unit (IWU). DB (Data Base) cooperates with CCFP in order to ensure management of connections of system users (Kuśmińska-Fijałkowska A., Eukasik Z. 2013) DECT system is mainly used to ensure the socalled basic connections serving to sound transmission (basic connections) and connections serving to data transmissions, faxes etc. (advanced connections). It is possible thanks to cooperation of the groups of protocols defined as a DECT protocol. (Wesolowski K. 2003). This protocol is divided into 4 layers: PHL (Physical Layer), MAC (Medium Access Control). This layer is internally divided into 2 sublayers: CCF (Cluster Control Functions) and CSF (Cell Site Functions), DLC (Data Link Control), NWK (Network Layer). Figure 2 presents a comparison of layers of DECT protocols with a model ISO OSI. System DECT is also described as the so-called access system, that is system enabling cordless access to services offered by other systems, for example, ISDN (Fig. 1) Therefore, a set of protocols is usually extended by an element called IWU (Inter Working Unit), of which task is to adjust services offered by NWK to the needs of an appropriate layer of a system, to which access is enabled. An example of cooperation of protocols with ISDN network is presented on Figure 3 . Figure 1. Realization of DECT system in the area with a complex spatial structure - land transshipment terminal. Layers of protocol realized in blocks are marked. CCFP -central control fixed part, RFP - Radio Fixed Part Figure 2. Comparison of DECT protocol and ISO OSI model Figure 3. Cooperation protocols ISDN DECT Coverage of RFP according to DECT specification is maximum https://www.w3.org/1998/Math/MathML"> 500 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in an open area, although most of producers say that maximum distance is https://www.w3.org/1998/Math/MathML"> 300 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . When we use telephone inside a building, coverage usually doesn't exceed https://www.w3.org/1998/Math/MathML"> 50 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Apart from good quality of sound, DECT systems also offer relatively high possibility of extension. Standard RFP can serve to 12 mobile devices, while one mobile can be registered in maximum 10 RFPs. It means that when we use a telephone in an open area, maximum 6 users switched to one telephone line can speak in the area of maximum 2.5 square kilometres. Using specialist subscriber exchanges, DECT systems can serve more users. Some sources even say that maximum number of users of DECT systems can even reach 10000 per square kilometre. Apart from connections to a fixed network, RFPs also enable connections with mobile parts or between these parts. Starting from 1997 , a possibility of extension of DECT systems increased even more. GAP (Generic Access Profile) - standard created by ETSI enables extension of DECT systems also with the use of devices from various producers. Buying another receiver to RFP, we can be sure that it will work properly. In case of DECT technology, band 1880-1900 https://www.w3.org/1998/Math/MathML"> M H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> divided into 120 channels is used to transmission. It allows to improve considerably the quality of sound and reduce interferences of signals coming from RFPs of various subscribers or various receivers. When there are interferences of signals, channel of transmission can be changed. For some time, information is transmitted on two channels, then electronic systems of RFP check, which channel offers better quality and choose it to further data transmission. The situation is similar in case of translocation of users within a coverage of various RFPs. When user comes closer to RFP with a stronger signal, then (provided that receiver has appropriate access authorization) transmission taken over by a station with a stronger signal. User does not see any change. However, we should add that not all DECT systems offer a possibility of change of RFP during conversation. Most of house telephones do not have such a function. DECT system divides radio channel into three dimensions: spatial, frequency and time. (Wesolowski K. 2003). Spatial division is a limited coverage of propagation of radio-waves around RFPs, thus creating cells, in which a given RFP is heard by PP. Standard allows two levels of power of transmitters https://www.w3.org/1998/Math/MathML"> - 250 m W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 2,5 m W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Frequency division is realized by applying a dozen or so carrier frequencies. Basic standard uses 10 carrier frequencies distant from each other by https://www.w3.org/1998/Math/MathML"> 1,728 M H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> within a coverage of 1880- https://www.w3.org/1998/Math/MathML"> 1900 M H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with frequencies: https://www.w3.org/1998/Math/MathML"> f c = 1897,344 M H z - c ⋅ 1,728 M H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where c is a number of carrier with a coverage https://www.w3.org/1998/Math/MathML"> 0,1 , 2 … . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Standard allows to increase a number of carriers by the so-called extended carriers with a frequency: https://www.w3.org/1998/Math/MathML"> f c = f 9 + c ⋅ 1,728 M H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> while https://www.w3.org/1998/Math/MathML"> c > 9 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Inaccuracy of carrier frequency used by RFP shouldn't exceed https://www.w3.org/1998/Math/MathML"> 50 k H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Carriers are modulated with the use of modulation GFSK (Gaussian Frequency Shift Keying) with a nominal deviation of frequencies https://www.w3.org/1998/Math/MathML"> 288 k H z https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Binary flowability of integrated channel in one band is https://www.w3.org/1998/Math/MathML"> 1152 k b i t / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In order to get time division, TDMA technique is applied. One frame lasts https://www.w3.org/1998/Math/MathML"> 10 m s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and consists of 11520 bits. Frame is divided into 24 time slots (full slot) In first 12 time slots, FP transmission usually occurs (Fig. 4). The last 12 slots of frame are designated to PP transmission. These slots are paired, that is, for example, when FP conducts a transmission in slot 3 , PP conducts transmission in a slot 15 , with whom FP realizes this connection. Corresponding to each other pairs of time slots in a given frequency are called physical channels. (Jackowski S. 2005). Time slots, in the extended connections, can be (Fig. 5, Fig. 6) paired (double slot) or divided further into two parts (half slot). (Wesołowski K. 2003). Figure 4. DECT frame structure 2 3 4 5 double slot doble slot Figure 5. Time slots can be combined two by two, creating gaps double Figure 6. Slots can be divided into two half-slots (half slot) In the first case, number of physical channels will be two times smaller, whereas, in the second case two times higher. It enables to increase binary flowability two times to a given subscriber, or decrease basic flowability two times. Inside time slots, radio terminals can transmit data packets. Standard distinguishes 4 sizes of data packets: short, normal, small capacity and large capacity. (Wesolowski K. 2003). Their features are the following: Short packet, 96 bits in length, is used only by RFP to spread with the use of the so-called dummy bearers (beacokn). Full packet, 424 bits in length, is used in the basic connections. Large capacity packet (double packet), 904 bits in length, is used in the extended connections. This packet occupies double time slot. Small capacity packet, 184 bits in length, occupies half slot, can be applied in the extended connections. Apart from data, each packet must contain synchronization bits (different for FP and PP), field Z (except for short packet). Packets with other slots are separated by protective field, in which there is no transmission (Fig. 6). Field Z, which is a repetition of last bits of packet, enables to detect and counteract of the so-called slipping collisions, that is, a situation when as a result of lack of synchronization of transmission in different slots, it starts overlapping. Protective field provides space between packets transmitted by different radio terminals. (EN 300 175-1. 1999). In case of DECT system, it is also possible to obtain channels with an increased flowability. In a borderline case, using all slots to data transfer from a one subscriber, we can obtain effective flowability https://www.w3.org/1998/Math/MathML"> 12 × 32 = 384 k b i t / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Power of transmitter is approximately https://www.w3.org/1998/Math/MathML"> 10 m W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Total number of channels in a DECT system is 120 , therefore, with such a low power of transmitter, system can serve high telecommunications traffic of 10000 erlangs https://www.w3.org/1998/Math/MathML"> / k m 2 / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> level. (Jackowski S. 2005). Block arrangement of PP of a system is presented on Figure 7. Figure 7. Block arrangement of PP of DECT system 17. CONCLUSIONS ICT System implemented in the areas with a complex spatial structure, which is a reloading terminal should meet the following conditions: 1 To provide constant communications in the area of terminal dislocation; 2 To enable realization of cumulative digital communications of the short packets of information from any object that can be found in the area of terminal; 3 Selective bidirectional contact with external users should be possible, both communicative and in a form of short cables, from any external system; 4 Information exchanged in a system of communications should be protected from access to it by the unauthorized people. The analysis, in which parameters relevant for a reloading terminal were taken into consideration, proved that proposed system of cordless telecommunication DECT can fulfil given requirements the best. Many aspects concerning proposed standard should be considered parameters, telecommunications traffic, specific area for propagation of electromagnetic wave, quality of radio transmission between RFP and PP. 18. REFERENCES Brill J., Lukasik Z.: „Economic, technical and strategic intermodal transport" Rail Transport Technology magazine 3/2014, str. 12-24, ISSN 1232-3829 Craven P., Wong R., Fedora N.; et al. Book Group Author(s): ION Studying the Effects of Interference on GNSS Signals Craven, Paul; Wong, Ronald; Fedora, Neal; et al. Conference: International Technical Meeting of the Institute-of-Navigation Location: San Diego, CA Date: JAN 27-29, 2013 Sponsor(s): Inst Nav Proceedings of the 2013 International Technical Meeting of the Institute of Navigation Pages: 893-900 Published: 2013 EN https://www.w3.org/1998/Math/MathML"> 300 175 - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CI); part 1 Overview, V.1 4.2., June 1999. EN https://www.w3.org/1998/Math/MathML"> 300 175 - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CD); part 3 Medium Access Control (MAC) Layer, V.1 4.2., June 1999. Eugen, Rosca; Serban, Raicu; Augustin, Rosca Mircea; et al. Transshipment modelingand simulation of of container port terminals Edited by: Carausu C; Cohal V; Doroftei I; et al. Conference: ModTech International Conference - Modern Technologies in Industrial Engineering Location: Profess Assoc Modern Mfg Technol, Sinaia, Romania Date: JUN 27-29, 2013 Sponsor(s): Silesian Univ Technol; Maritime Univ Constanta Modern Technologies in Industrial Engineering Book Series: Advanced Materials Research Volume: 837 Pages: 786-791 Published: 2014 Jackowski S.: „Telecommunication", cz. 2. Technical University of Radom 2005 Li T., Wang X., Zheng Ch. et al.Investigation on the Placement Effect of UHF Sensor and Propagation Characteristics of PD-induced Electromagnetic Wave in GIS Based on FDTD Method IEEE Transactions on Dielectrics and Electrical Insulation Volume: 21 Issue: 3 Pages: 1015-1025 Published: JUN 2014 Kisilowski J., Krzyszkowski A.: „A fast train air transport” Logistics 3/2014 Kussminska-Fijałkowska A. Eukasik Z.: „The transmission of the information of the system of telecommunicational https://www.w3.org/1998/Math/MathML"> D E C T https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the trans-shipping terminal". 8 Intemational Navigational Symposium TransNav'09, Gdynia 2009 , Poland. Monograph ,Marine Navigation and Safety of Sea Transportation", p. 317-323, ISBN 978-0-415-80479-0 Kuŝmin'ska-Fijałkowska A., Eukasik Z.: "Management of a transshipment terminal supported by ICT systems", 13th International Conference, „ransport Systems Telematics International Conference "Transport Systems Telematics Katowice-Ustron, Poland 2013, ISBN 978-83-927504-5-1, pp. 60 PUBLIKACJA International Scientific Joumal: Archives of Transport System Telematics, Volume 6, Issue 4, November 2013, ISSN 1899-8208, pp 17-20 Kozyra J.: „The use biofuels in transport". Logistyka Nr 3/2009. Tuttlebee W.H.W.: Cordless telephones and cellular radio: Synergies of DECT and GSM (Reprinted from Cordless Telecommunications Worldwide) Electronics & Communication Engineering Journal, Volume: 8 Issue: 5 , October 1996, ISSN: 0954-0695, pp 213-223 Van Vorst, D. G., Yedlin Ma. J., Virieux J; et al. Threedimensional to two-dimensional data conversion for electromagnetic wave propagation using an acoustic transfer function: application to cross-hole GPR data. Geophysical Journal International, Volume: 198, Issue: 1 , July 2014, ISSN 0956-540X, pp 474-483 Wesołowski K.: Mobile radio systems, 2003. https://www.w3.org/1998/Math/MathML"> Z h u https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Bo O., Chen K., Jia, N. et al. Dynamic control of electromagnetic wave propagation with the equivalent principle inspired tunable metasurface Scientific Reports Volume: 4 Article Number: 4971 Published: MAY 152014 Establishing a Framework for Maritime Spatial Planning in Europe A. Kuśmińska-Fijałkowska & Z. Łukasik University of Technology and Humanities in Radom, Poland Abstract In this paper authors present a European framework for planning for EU countries that have access to the sea. Maritime spatial planning will contribute to the effective management of marine activities and the sustainable use of marine and coastal resources, by creating a framework. Through maritime spatial plans, Member States can reduce the administrative burden and costs in support of their action to implement other relevant Union legislation. The Member States of the European Union are required to develop plans for zoning marine areas, until 31 March 2021 . 19. INTRODUCTION The high and rapidly increasing demand for maritime space for different purposes, such as installations for the production of energy from renewable sources, oil and gas exploration and exploitation, maritime shipping and fishing activities, ecosystem conservation, the extraction of raw materials, tourism, require an integrated planning and management approach. In order to promote the sustainable coexistence of uses and, where applicable, the appropriate apportionment of relevant uses in the maritime space, UE (Directive 2014/89/UE 2014) introduced a framework should be put in place that consists of the establishment and implementation by Member States of maritime spatial planning, resulting in plans. Maritime spatial planning will contribute to the effective management of marine activities and the sustainable use of marine and coastal resources, by creating a framework for consistent, transparent, sustainable and evidence- based decision-making. In order to achieve its objectives, this Directive (2014/89/UE 2014) should lay down obligations to establish a maritime planning process, resulting in a maritime spatial plans; such a planning process should take into account land-sea interactions and promote cooperation among Member States. Without prejudice to the existing Union acquis in the areas of energy, transport, fisheries and the environment, this Directive should not impose any other new obligations, notably in relation to the concrete choices of the Member States about how to pursue the sectored policies in those areas, but should rather aim to contribute to those policies through the planning process. Maritime spatial planning will contribute, inter alia, to achieving the aims of Directive https://www.w3.org/1998/Math/MathML"> 2009 / 28 / E C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the European Parliament and of the Council, Council Regulation (EC) No 2371/2002, Directive https://www.w3.org/1998/Math/MathML"> 2009 / 147 / E C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the European Parliament and of the Council, Council Directive 92/43/EEC, Decision No https://www.w3.org/1998/Math/MathML"> 884 / 2004 / E C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the European Parliament and of the Council, Directive https://www.w3.org/1998/Math/MathML"> 2000 / 60 / E C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the European Parliament and of the Council, Directive https://www.w3.org/1998/Math/MathML"> 2008 / 56 / E C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , recalling the Commission communication of 3 May 2011 entitled 'Our life insurance, our natural capital: an EU biodiversity strategy to https://www.w3.org/1998/Math/MathML"> 2020 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the Commission communication of 20 September 2011 entitled 'Roadmap to a Resource Efficient Europe', the Commission communication of 16 April 2013 entitled 'An EU Strategy on Adaptation to Climate Change' and the Commission communication of 21 January 2009 entitled 'Strategic goals and recommendations for the EU's maritime transport policy until 2018', as well as, where appropriate, those of the Union's Regional Policy, including the sea-basin and macroregional strategies. (Directive 2014/89/UE 2014). 20. MARITIME SPATIAL PLANNING Within the Integrated Maritime Policy of the Union, that framework provides for the establishment and implementation by Member States of maritime spatial planning, with the aim of contributing to the objectives specified in point 5 , taking into account land-sea interactions and enhanced cross-border cooperation, in accordance with relevant Unclos provisions. In the framework of the European Spatial Planning definitions used (Directive 2014/89/UE 2014). 'Integrated Maritime Policy' (IMP) means a Union policy whose aim is to foster coordinated and coherent decision- making to maximize the sustainable development, economic growth and social cohesion of Member States, and notably the coastal, insular and outermost regions in the Union, as well as maritime sectors, through coherent maritime-related policies and relevant international cooperation; 'maritime spatial planning' means a process by which the relevant Member State's authorities analyze and organize human activities in marine areas to achieve ecological, economic and social objectives; 'marine region' means the marine region referred to in Article 4 of Directive https://www.w3.org/1998/Math/MathML"> 2008 / 56 / E C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; 'marine waters' means the waters, the seabed and subsoil as defined in point (1)(a) of Article 3 of Directive https://www.w3.org/1998/Math/MathML"> 2008 / 56 / E C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and coastal waters as defined in point 7 of Article 2 of Directive https://www.w3.org/1998/Math/MathML"> 2000 / 60 / E C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and their seabed and their subsoil. 21. OBJECTIVES OF MARINE SPATIAL PLANNING Europe's maritime spatial planning shall aim to contribute to the objectives (Directive 2014/89/UE 2014): 1 When establishing and implementing maritime spatial planning, Member States shall consider economic, social and environmental aspects to support sustainable development and growth in the maritime sector, applying an ecosystembased approach, and to promote the coexistence of relevant activities and uses. 2 Through their maritime spatial plans, Member States shall aim to contribute to the sustainable development of energy sectors at sea, of maritime transport, and of the fisheries and aquaculture sectors, and to the preservation, protection and improvement of the environment, including resilience to climate change impacts. In addition, Member States may pursue other objectives such as the promotion of sustainable tourism and the sustainable extraction of raw materials. 3 Directive https://www.w3.org/1998/Math/MathML"> ( 2014 / 89 / U E ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is without prejudice to the competence of Member States to determine how the different objectives are reflected and weighted in their maritime spatial plan or plans. 22. MINIMUM REQUIREMENTS FOR Member States shall establish procedural steps to contribute to the objectives listed in point 2 , taking into account relevant activities and uses in marine waters. Member States: take into account land-sea interactions; take into account environmental, economic and social aspects, as well as safety aspects; (Carcamo Francisco, Garay-Fluehmann P, Squeo Rosa, A Francisco,, et al. 2014; GonzalezMirelis, Genoveva; Lindegarth, Mats; Skold, Mattias 2014; Michelle V., William G., Heather G., 2012). aim to promote coherence between maritime spatial planning and the resulting plan or plans and other processes, such as integrated coastal management or equivalent formal or informal practices; ensure the involvement of stakeholders in accordance with Article 9 (Directive 2014/89/UE 2014) organize the use of the best available data in accordance with Article 10 (Directive 2014/89/UE 2014); ensure trans-boundary cooperation between Member States in accordance with Article 11 (Directive 2014/89/UE 2014); promote cooperation with third countries in accordance with Article 12 (Directive 2014/89/UE 2014). Maritime spatial plans shall be reviewed by Member States as decided by them but at least every ten years. 23. MARITIME SPATIAL PLANNING RP When establishing and implementing maritime spatial planning, Member States shall set up maritime spatial plans which identify the spatial and temporal distribution of relevant existing and future activities and uses in their marine waters, in order to contribute to the objectives set out in point 2 . Member States shall take into consideration relevant interactions of activities and uses. Without prejudice to Member States' competences, possible activities and uses and interests may include: aquaculture areas, fishing areas, installations and infrastructures for the exploration, exploitation and extraction of oil, of gas and other energy resources, of minerals and aggregates, and for the production of energy from renewable sources, maritime transport routes and traffic flows, military training areas, - nature and species conservation sites and Development of spatial study of the conditions of protected areas, raw material extraction areas, scientific research, submarine cable and pipeline routes, tourism, underwater cultural heritage. The main purpose of maritime spatial planning is to promote sustainable development and to identify the utilization of maritime space for different sea uses as well as to manage spatial uses and conflicts in marine areas. Maritime spatial planning also aims at identifying and encouraging multi-purpose uses, in accordance with the relevant national policies and legislation. In order to achieve that purpose, Member States need at least to ensure that the planning processes Deadline for completion of the first stage is 07 . result in a comprehensive planning identifying the different uses of maritime space and taking into consideration long-term changes due to climate change. Figure 1.Phases of the project plan, zoning Polish marineas part of Phase II is planned to developPhases of the project plan, zoning Polish marine and forecasts as well as public consultation.areas.I AS. I - study of the conditions to the planPHASE I - study of the conditions to the plan. WBs-84 Figure 1. The M Figure 1. The Maritime spatial planning RP [11] Development of spatial study of the conditions of Polish sea areas with spatial analysis https://www.w3.org/1998/Math/MathML"> ( 03 / 07 / 2014 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of management of marine areas; to perform spatial analysis. https://www.w3.org/1998/Math/MathML"> agreement Maritime Institute in Gdansk). - As part of Phase I is scheduled: - to collect data on marine waters; of the collect information about how the development planning is between sea and land plan; to identify - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> agreement Maritime Institute in Gdansk). - As part of Phase I is scheduled: - to collect data on marine waters; of the collect information about how the development planning is between sea and land plan; to identify - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> agreement Maritime Institute in Gdansk). - As part of Phase I is scheduled: - to collect data on marine waters; of the collect information about how the development planning is between sea and land plan; to identify - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> agreement Maritime Institute in Gdansk). - As part of Phase I is scheduled: - to collect data on marine waters; of the collect information about how the development planning is between sea and land plan; to identify - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> agreement Maritime Institute in Gdansk). - As part of Phase I is scheduled: - to collect data on marine waters; of the collect information about how the development planning is between sea and land plan; to identify - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> agreement Maritime Institute in Gdansk). - As part of Phase I is scheduled: - to collect data on marine waters; of the collect information about how the development planning is between sea and land plan; to identify - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> agreement Maritime Institute in Gdansk). - As part of Phase I is scheduled: - to collect data on marine waters; of the collect information about how the development planning is between sea and land plan; to identify - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> agreement Maritime Institute in Gdansk). - As part of Phase I is scheduled: - to collect data on marine waters; of the collect information about how the development planning is between sea and land plan; to identify - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> agreement Maritime Institute in Gdansk). - As part of Phase I is scheduled: - to collect data on marine waters; of the collect information about how the development planning is between sea and land plan; to identify - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> agreement Maritime Institute in Gdansk). - As part of Phase I is scheduled: - to collect data on marine waters; of the collect information about how the development planning is between sea and land plan; to identify - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> agreement Maritime Institute in Gdansk). - As part of Phase I is scheduled: - to collect data on marine waters; of the collect information about how the development planning is between sea and land plan; to identify - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> agreement Maritime Institute in Gdansk). - As part of Phase I is scheduled: - to collect data on marine waters; of the collect information about how the development planning is between sea and land plan; to identify - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Deadline for completion of the first stage is 0712. 2014 24. PHASE II-develop a strategic plan As part of Phase II is planned to develop a plan Nonce or binectons mavitme ornces PHASE III - Transboundary consultations (planned completion date 2016-2017) 25. NEXT PHASE Complementary research resulting from the indications contained in the strategic plan; Develop plans for the Lagoons, port areas and waters requiring detailed plans identified in the strategic plan (scheduled for completion in 2021) Problems encountered in drafting zoning plan Polish marine areas: lack of expected changes in the law on maritime areas of the Republic of Polish and Maritime Administration (lack of procedures to develop a project plan); lack of funds (ongoing work on the multi-annual program, which provides funding for the years 2015 to 2021) (Stelmaszyk-Świerczyńska A, Mostowiec A. 2014). 26. CONCLUSIONS Through maritime spatial plans, Member States can reduce the administrative burden and costs in support of their action to implement other relevant Union legislation. The timelines for maritime spatial plans should therefore, where possible, be coherent with the timetables set out in other relevant legislation, especially: Directive https://www.w3.org/1998/Math/MathML"> 2009 / 28 / E C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which requires the share of energy from renewable sources in gross final consumption of energy in 2020 to be at least https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and which identifies coordination of authorization, certification and planning procedures, including spatial planning, as an important contribution to the achievement of the Union's targets for energy from renewable sources; Directive https://www.w3.org/1998/Math/MathML"> 2008 / 56 / E C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and point 6 of Part A of the Annex to Decision https://www.w3.org/1998/Math/MathML"> 2010 / 477 / E U https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which require Member States to take the necessary measures to achieve or maintain good environmental status in the marine environment by 2020 and which identify maritime spatial planning as a tool to support the ecosystembased approach to the management of human activities in order to achieve good environmental status; Decision No https://www.w3.org/1998/Math/MathML"> 884 / 2004 / E C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which requires that the trans-European transport network be established by 2020 by means of the integration of Europe's land, sea and air transport infrastructure networks. (Directive 2014/89/UE 2014). Member States are required to develop plans for zoning marine areas until 31 March 2021. 27. REFERENCES Carcamo F., Garay-Fluehmann P, Squeo R.,,; "Using stakeholders' perspective of ecosystem services and biodiversity features to plan a marine protected area" Environmental Science & Policy, Volume: 40 , Pages: 116 131 Published: Jun 2014 Directive 2014/89/EU of the European Parliament and of the Council of 23 July 2014 establishing a framework for maritime spatial planning Directive 2008/56/EC of the European Parliament and of the Council of 17 June 2008 establishing a framework for Community action in the field of marine environmental policy (Marine Strategy Framework Directive) (OJ L 164, 25.6.2008, p. 19). Directive 2009/28/EC of the European Parliament and of the Council of 23 April 2009 on the promotion of the use of energy from renewable sources and amending and subsequently repealing Directives https://www.w3.org/1998/Math/MathML"> 2001 / 77 / E C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 2003/30/EC (OJ L 140,5.6.2009, p. 16). Directive 2009/147/EC of the European Parliament and of the Council of 30 November 2009 on the conservation of wild birds (OJ L 20, 26.1.2010, p. 7). Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora (OJ L 206, 22.7.1992, p. 7) Decision No https://www.w3.org/1998/Math/MathML"> 884 / 2004 / E C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the European Parliament and of the Council of 29 April 2004 amending Decision No https://www.w3.org/1998/Math/MathML"> 1692 / 96 / E C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on Community guidelines for the development of the trans-European transport network (OJ L 167, 30.4.2004, p. 1). Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy (OJ L 327, 22.12.2000, p. 1). Gonzalez-Mirelis, G.; Lindegarth, M.; Skold, M. "Using Vessel Monitoring System Data to Improve Systematic Conservation Planning of a Multiple-Use Marine Protected Area, the Kosterhavet National Park (Sweden)" AMBIO Volume: 43 Issue: 2 Pages: 162-174 Published: MAR 2014 Council Regulation (EC) No 2371/2002 of 20 December 2002 on the conservation and sustainable exploitation of fisheries resources under the Common Fisheries Policy (OJ L 358, 31.12.2002, p. 59). Stelmaszyk-Swierczynnska A, Mostowiec A. "Zoning plans Polish maritime areas-problems and challenges Maritime Offices". Maritime Office in Gdynia. Jastarnia 04/09/2014 Voyer M., Gladstone W..., Goodall H..: "Methods of social assessment in Marine Protected Area planning: Is public participation enough?" Marine Policy, Volume: 36 Issue: 2 , Pages: 432-439 Published: Mar 2012. Application of Intelligent Geoinformation Systems for Integrated Safety V.V. Popovich, O.V. Smirnova, M.V. Tsvetkov & R.P. Sorokin SPIIRAS Hi Tech Research and Development Office Ltd, St. Petersburg, Russia Abstract The intelligent geoinformation systems are essential for successful analysis of the complicated situations connected with the safety of marine activities. Currently, different dangerous unforeseen situations can develop in offshore zone, such as ship collisions, ecological catastrophes, terrorism, piracy and others. Existing offshore monitoring systems do not allow us to solve problem related to integrated safety and situation assessment and also their modernization will require significant costs. Thus, development of new technologies and tools in intelligent geoinformation systems will allow to operationally estimate current dangerous situations and to predict their progress. This paper considers tools and technologies, intellectual data processing capabilities and complicated situation assessment. 28. INTRODUCTION Developing of maritime situation monitoring systems is without doubt relevant issue. Its actuality first of all is dictated by growing number of personal vessels, increasing complexity of vessel's navigation due to large variety of installed navigational aids, poor quality of special training. Moreover, increases the rate of various dangerous situations at sea such as ship collision, ecological disasters, natural hazards (storm, snow fall, fog etc.), piracy, terrorism etc. Many scientific researches, technological developments for building effective maritime situation monitoring systems are oriented on the increase of navigation safety. However, most of these systems possess a limited functionality and low level of data analysis automatization. Global and local maritime situation monitoring systems provide data collection (from radar, AIS and other sources), data preprocessing, complex maritime route planning, monitoring and analysis of current maritime situation in navigation area. To increase the quality of visualization and processing of maritime situation data, modern monitoring systems are being developed based on GIS-technologies. GIS-technologies support: precise binding, systematization, selection and integration of all incoming and stored data (interconnect address space); - composite nature and illustration of data representation for decision making; capability to dynamically model processes and effects; capability to automatically solve tasks, associated with location areas' peculiarities analysis; capability for operational analysis in case of dangerous situation arising. However, application of traditional GIS (ArcGIS, MapInfo) for solving such tasks is highly laborious and costly. The user of such GIS has to analyse and process data about unfolding maritime situation on his own and make decisions about further actions relying on his intuition and experience. In this paper we present new approach for development and building maritime situation monitoring systems and estimating safety of maritime activities. Main factor of this approach is application of intelligent GIS, that allows to solve tasks, related to automatized control over development of complex situations, interpretation of analysis results and intelligent identification of location and nature of activities of maritime objects. 29. RELATED WORKS In paper (Claramunt et al. 2007) the issue of application of GIS-technologies in maritime situation monitoring systems is closely examined, capabilities of modern GIS for decision making support of operator is analysed. Also, in the paper peculiarities of collecting data from sensors (AIS, ECDIS) are discussed and distributed architecture of building is maritime situation monitoring systems, operating in real-time mode, is suggested. In paper (Tetreault 2010 ) the issue of utilization of AIS in perspective navigation control systems is considered, perspective directions of application of such sensors in coast surveillance systems are disclosed. In paper (Goralski, Gold, 2007) is given example of safe navigation system development based on GIS. Some attention is given to the question of navigation monitoring in vessel's location area, aspects of system functioning in real-time mode are regarded. It is necessary to note that given work is dedicated to the problem of shipborne system development. Integration of solution suggested in (Goralski&Gold 2007) with external intelligent navigation system is presented as one of the new lines of research. Paper (Baylon&Santos 2013) describes capabilities of modern GIS for 'intelligent decision making' in information systems associated with safety of maritime activities. Authors pay close attention to perspectives of cooperation of different organizations that possess important information about various fields of maritime activities. Also, aspects related to training personnel to operate monitoring and safe navigation systems are considered in this work. Papers (Popovich, Potapichev et al. 2006, Popovich, Claramunt et a1. 2009) deal with concept of intelligent GIS and questions concerning application of IGIS for solving safe navigation problems. In work (Popovich, Claramunt et al. 2009) formalized concept of tactical situation, associated with vessels' location in sea area in given along with general architecture of IGIS that allows to solve vast spectrum of issues, related to safe navigation. In full paper (Popovich 2013) questions about development of intelligent GIS for maritime situation monitoring are studied in detail. Also, this work focuses on issues of integration, harmonization and fusion of data, obtained from various sources (sensors). As a basis for building IGIS ontology approach is offered. 30. MARITIME SITUATION ASSESSMENT Estimation and detection of dangerous situations is one of the key problems of maritime activities monitoring and decision support. The term maritime situation denotes a combination of some parameters, directly or indirectly defining observable system's state in given point of time. Maritime situation assessment represents analysis of certain characteristics for obtaining conclusion about current state of system and its possible state in near future (Blasch 2002). The term situation management, in turn, denotes purposeful influence on system aiming at changing the situation to our benefit. Stated influence can be accomplished by executing certain actions, oriented on changing system's properties, characterized by detected features. Maritime situation assessment suggests: detection of factors (features) that influence development of dangerous situations in maritime activities location; visualized mathematical (computer) modelling of current situation in real-time mode; prediction of further development of dangerous situations and their analysis; generation and execution of decisions regarding further actions concerning arising dangerous situations; Solving these tasks must be constructed on mathematical analysis methods, efficient numerical methods and algorithms. We believe that efficient tool for solving such tasks can be intelligent GIS (IGIS). 31. IGIS FOR ESTIMATION OF MARITIME ACTIVITIES' SAFETY The term intelligent GIS is defined here as GIS that includes integrated tools and/or systems of artificial intelligence (AI) (Popovich 2003). Figure 1 illustrates IGIS architecture. The central part of the IGIS is knowledge base including ontology. Ontology presents the 'framework' for representation concepts and relations between them in subject domain. Another part of knowledge base is storage of subject domain real object instances Various active and passive sensors (AIS, radar) as well as information systems of global and local level can act as sources of information for maritime navigation system. While obtaining data from different sources the following problems may arise. First problem is duplicated information i.e. obtained information from different sources about same objects. However, similar data about same object is not necessarily a disadvantage since it increases credibility of data and consequently increases quality of specific decisions. One of the means for solving duplication problem and increasing quality of data obtained from various sources is application of concept of integration, harmonization and fusion of data which is described in (Popovich 2013). Second problem is the issue of discrepancy between concepts in different systems. To format initial data to one standard we have developed a unified information interoperability model on basis of ontology database. Information interoperability model includes three ontology levels: domain ontology, geographical ontology and upper ontology. GIS-interface is a program component for visual representation of geo-spatial data in various digital formats and of objects stored in knowledge base (Fig. 2). It combines different sources of geo-spatial data and program components that execute data processing using traditional methods. GIS-interface allows: to update and display data in real-time mode along with processed results, prognosed and modelled data; to display all infrastructure of observed area of maritime activities; to set combinations of algorithms for execution of all stages of dangerous situation modelling (verification, interpolation, prediction); Figure 2. GIS Interface Library of mathematical functions is one of the important parts of intelligent GIS. Set of functions has to be open for access by any subsystem of IGIS, support changeability and expansion. For example, for modelling spatial processes associated with dangerous situation development in maritime activities location following functions from library can be applied: mathematical model of different dangerous situations (e.g. oil spill, seizure of vessel by pirates, terrorist and etc.); vessel navigation on given route; search in location of rescue operation and etc. To increase the quality of specific decisions made by user it is necessary to include prognostic models in mathematical functions library, i.e. such models, that allow to obtain estimation of dangerous situation development in future instances of time, based on data obtained to the current point of time. It should be noted that any functions from mathematical functions library can be used in creating production rules for expert system. The term expert system (ES) denotes a system that utilizes expert knowledge (knowledge form specialists) to provide qualified solution to tasks in given field of study (Popovich 2013). Such systems are able to present knowledge, to clarify (examine) their processes-reasoning and are intended for fields of study where a person can reach professional level only after years of special education and training. Expert knowledge is represented in form of condition-action rules and is saved in IGIS knowledge database. Let us note that any of mathematical functions given in library can be used in creating rules for IGIS expert system. Expert system allows to execute integrated assessment of maritime activities' safety and suggest further actions to user in case of dangerous situation arising. For example, if system's user views successive triggering of rules: "'Dangerous closingin of vessels 1 and 2 " and "Vessel 2 has left channel", evident is situation: "Vessel 2 has violated regime of navigation". IGIS modelling system is intended for computer modelling of various spatial processes and also for visual generation of corresponding scenarios of processes development based on expert systems technology and represented as ontology database. Visual representation of the modelling allows the user to effectively estimate occurring process. Modelling system allows us to solve the following tasks: 1 Building models of complex spatial processes based on their description in form of visual scenarios that are represented as two-dimensional digraph (block-scheme) where nodes are separate scenario tasks and decision making points in which scenario branches on various execution routes depending on satisfaction of specified conditions (Fig. 3). Scenario tasks can be executed both sequentially and in parallel, depending on block-scheme. For merging parallel branches special nodes "connectors" are used. Scenario tasks consist of individual atomic actions and are as well represented as blockschemes connecting atomic actions. Task's actions can also be executed both sequentially and in parallel, depending on task's blockscheme. 2 Construction, debugging and testing of scenarios by field of study specialists mostly with use of visual drag-and-drop of icons, corresponding to tasks, solutions and actions, to the scenario and task scheme form and connecting them in accordance with scenario logic. Figure 3. Example of terrorist situation assessment 3 Scenario execution of complex spatial processes in optional time scale against digital map background, represented as moving simulated point objects with changing form, size, location, colour, transparency and etc. extended objects along with messages on natural professional language. 4 Interaction of number of complex processes, modelled on one as well as on several machines in network. 5 Manual object and process control option, modelling process in general (start/stop, time scale change, maps and etc.), scenario replay from control point, time jumps and etc. 32. CASE STUDY As an explanation, consider the following situations that demonstrate maritime dangerous situation assessment using the proposed IGIS-technologies. Situation 1. The cargo ship was captured by pirates in the Gulf of Aden. The search and rescue operation scenario on release of the seized cargo ship was developed. Figure 4 illustrates the example of this scenario. Release of the cargo ship (on the Figure 5 cargo ship is marked by blue color) is carried out by group including helicopter and two boats. During implementation of the developed scenario cargo ship seized by pirates was detected in 0 hours 50 minutes in point with coordinates {latitude https://www.w3.org/1998/Math/MathML"> 1237 ' 19 ' ' ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> longitude https://www.w3.org/1998/Math/MathML"> 470 ' 6 ' ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (data are displayed in information window of expert system). Results of modelling of search and rescue operation on release of the cargo ship seized by pirates are given in Table 1. Also these data are displayed in information window of expert system (Fig. 5 ). Figure 4. Scenario of the seized cargo ship release. Figure 5. Modelling of the seized cargo ship release. Table 1. Modelling results beginning operation Number of killed Number of wounded Pirates Hostages 32 4 3 Members of release 25 2 5 group 1 1 Situation 2. In the Barents Sea at crash of the tanker there was an oil spill up to 5000 tons within 3 days. Figure 6 shows the scenario of oil spill taking into account navigation conditions around a dangerous situation, hydrographic and hydrometeorological situation. Also the assessment and the analysis of an ice situation are done. The mathematical model on the basis of which the scenario was developed considers coastline, ice situation in given area, water flows and weather conditions. Figure 7 shows modelling of the ecological search and rescue operation using IGIS. Figure 6. Oil spill modeling. Figure 7.1. Modelling of search and rescue operation. Figure 7.2. Modelling of search and rescue operation. Modelling of search and rescue operations allows to carry out the analysis of the estimated action plan, to estimate efficiency of rescue forces' actions, to consider various weather conditions and features of the area. 33. MOBILE IGIS On the base of stationary maritime situation monitoring system mobile version was created. The developed mobile IGIS is indented for mobile devices such as smartphones, laptops, and tablets with Android operating system. To update the information model and download the function modules Internet access is required. The generalized structure of the mobile IGIS is shown on Figure 8 . System includes the following elements: Cloud Services Platform - network of distributed servers that provides the set of necessary services; Client Integration Platform - application, that provides necessary interfaces for connecting modules that implement required features and that are installed on the mobile device. Function Modules Repository - storage of functional modules, capable to extend functionality of client's integration platform. https://www.w3.org/1998/Math/MathML"> B y m e a n s o f t h e s e s t r u c t u r e c o n p o n e n t s m e s t i s e t h e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> By means of these structure components mobile IGIS supports a wide range of functions and services such as: displaying the nautical chart showing the location of user's own ship and other maneuvering vessels; option of manual and automatic (AIS, radar) targets' drawing, target movement calculation; ship's routing between predetermined ports/points, accounting for the navigational area features and desired duration of movement/recreation; display and registration of weather data at a point/on the route, broadcast of storm warnings; calculation of maneuvers aimed at storm escape; speed and course calculations; solving tasks of maneuvering; positions' gaining and targets' passing; warning about dangerous maneuvers; entry into the closed/restricted areas, areas with special conditions for navigation, shallow water areas; warning of maneuvers on the route in advance (time and turning point, speed changes, etc.); - retrieving data about locations of other vessels equipped with mobile IGIS. Figure 9 shows a map where vessels' icons, routes (blue line) and additional information are plotted. The data on the map are updated in real time mode. By clicking on the vessel's icon additional information about the vessels, such as vessel's location (latitude and longitude), their lengths, widths, speeds, courses and names can be obtained. Various colors are used for displaying various vessels' types: green color for cargo vessels, blue for passenger vessels, orange - for high speed crafts, grey - for unspecified vessels. Figure 9. Vessels' routes. It is necessary to notice that the system is rather simple and easy in use; the user needs no additional knowledge and skills to start working with the system. Furthermore, the system can work in autonomous mode that allows using the system without a permanent connection with the server during a certain period of time. 34. CONCLUSIONS The safety of marine activities is the world priority, demanding solution on a global scale. Currently, not a single country is able to solve this problem independently, without interaction with the world communities. Every year the number of various dangerous maritime situations of both natural, and technogenic character increases. The proposed new tools and technologies of assessment and modelling of dangerous maritime situations on the basis of IGIS aim to increase safety of sea activities. We have presented new mathematical methods for modelling of complex geo-spatial processes. Main elements of suggested IGIS architecture for maritime situations assessment are library of mathematical functions and modelling system. As further research direction we suggest considerable expansion of services for the solution of a bigger class of tasks and problems connected with assessment of dangerous maritime situations, extensions of the knowledge base due to introduction of new rules and scenarios for new types of dangerous situations. We are actively developing user services and instruments for mobile IGIS as well. 35. REFERENCES Baylon, A. M., Santos, E. M. R. 2013. Introducing GIS to TransNav and its Extensive Maritime Application: An Innovative Tool for intelligent Decision Making? TransNav the International Journal on Marine Navigation and Safety of Sea Transportation, Vol. 7, Num. 4: 557-566. Blasch, E. 2002. Fundamentals of Information Fusion and Applications. Tutorial, TD2. Proceedings of the International Conference on Information Fusion. Claramunt, C., Devogele, T., Fournier, S., Noyon, V., Petit, M. Ray C. 2007. Maritime GIS: From Monitoring to Simulation Systems. In V. Popovich, M. Schrenk and K. Korolenko (Eds.) Proceedings of Information Fusion and Geographic Information Systems (IF&GIS'07), SpringerVerlag, LN series in Geoinformation and Cartography, May 27-29, 2007, St. Petersburg, Russia: 34-44. Goralski, R.I., Gold, C.M. 2007. The development of a dynamic GIS for maritime navigation safety. ISPRS Workshop on Updating Geo-spatial Databases with Imagery & The 5th ISPRS Workshop on DMGISs, 28-29 August 2007, Urumchi, China: 47-50. Popovich, V., Claramunt, C., Osipov, V., Ray, C., Wang, T., Berbenev, D. 2009. Integration of Vessel Traffic Control Systems and Geographical Information Systems. Proceedings REAL CORP 2009 Tagungsband 22-25 April 2009, Sitges: 271-284. Popovich, V., Potapichev, S., Pankin A., Shaida, S., Voronin, M., 2006. Intelligent GIS for Monitoring' Systems, SPIIRAS, Serial 3, Vol. 1, St. Petersburg, Russia: 172-184. Popovich, V., Pankin, A.V., Voronin, M.N., Sokolova, L.A. 2006. Intelligent Situation Awareness on a GIS Basis. In Proceedings of MILCOM 2006, October 24 26, Washington, USA. Popovich V, 2003. Concept of geoinformatic systems for information fusion. In: Proceedings of the lst international workshop on information fusion and geographic information system, September 17-20, St. Petersburg, Russia. Popovich, V. 2013. Intelligent GIS Conceptualization, Information Fusion and Geographic Information Systems. In V. Popovich, M. Schrenk and K. Korolenko (Eds.) Proceedings of Information Fusion and Geographic Information Systems (IF&GIS'13), Springer-Verlag, LN series in Geoinformation and Cartography, St. Petersburg, Russia: 17-44. Smirnova, O., Tsvetkov, M., Sorokin, R. 2014. Intelligent GIS for monitoring and prediction of potentially dangerous situations. In https://www.w3.org/1998/Math/MathML"> 14 th https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> International Multidisciplinary scientific geoconference SGEM 2014, Conference proceedings, Vol. 1, June 17-26, 2014: 659-666. Tetreault, B. J. 2010. Expanded use of Automatic Identification System (AIS) navigation technology in Vessel Traffic Services (VTS). In Ports 2010: Building on the Past, Respecting the Future, Proceedings of the https://www.w3.org/1998/Math/MathML"> 12 th https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Triennial International Conference, Jacksonville, Florida, April 25-28, 2010: 789-796. ABSTRACT: Santos Port, in São Paulo State Coastline (Brazil), is the most important maritime cargo transfer terminal in the Southern Hemisphere. The increasing number of larger vessels is the setting for the future. The port is located in an estuarine area with the depth maintained by high dredging rates, limiting possible choices for new estuarine expansions. Like many other important ports in estuarine areas that have already expanded seaward, Santos is planning its offshore port. The awareness on climate changing in maritime projects led Agencies from different countries, e.g. The Netherlands, UK and USA, to issue in the latest decades recommendations or requirements about sea level rise trend, which, associated with the tidal trend recorded, guided the tidal forecasting until 2100 . The tidal dataset of Santos Port is the longest in Brazil (1940 - 2014). The hindcasting meteorological mathematical models, calibrated and validated with the modelling of two different dataset of wave buoy, provided the wave climate assessment. 36. INTRODUCTION Santos Port (Figs. 1 to 3 ) throughputs approximately https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of Brazilian maritime cargo, more than 110 million tons per year (Fig. 4), and is the most important maritime cargo transfer terminal in the Southern Hemisphere. The increasing number of larger container vessels and the important oil and gas reserves in the Offshore Basin of Santos is the economic scenario for the future. The port is located in a confined estuarine area, comprising small inland fluvial deltas, with the hydrodynamical pattern induced by tides (Figs. 2 and 3) and the depth maintained by high dredging rates ( 7 million https://www.w3.org/1998/Math/MathML"> m 3 / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> year to maintain depth https://www.w3.org/1998/Math/MathML"> - 15.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Chart Datum (CD). To receive larger vessels there is the increasing necessity to expand the nautical areas (access channel, turning basins and berths) out off the estuarine area. Like many other important estuarine ports that have already expanded seaward (e.g. Rotterdam, Le Havre and Shanghai), Santos is planning its first offshore port, with jetties (Moreira 2009). Due to the high values involved of the facilities and infrastructures, it will be necessary minimize the risks of natural disasters. Hence, the conceptual planning for the new port must consider the climate changing in extreme events of tides and waves with a recommended recurrence period greater than 100 years. The tidal dataset of Santos Port is the longest in Brazil https://www.w3.org/1998/Math/MathML"> ( 1940 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - 2014). The awareness on climate changing in maritime projects led Agencies from different countries, e.g. The Netherlands, UK and USA, to issue in the latest decades recommendations or requirements about sea level rise (PIANC 2014a). These recommendations associated with the tidal trend recorded of Santos Port in the last 75 years, guided the tidal forecasting for 2050 and 2100 . The hindcasting meteorological mathematical models, calibrated and validated with the modelling of two different dataset of wave buoy, provided the wave climate assessment. 37. MATERIAL AND METHODS Data sets for this assessment were obtained from a physical model of Santos Bay, Estuary and nearby beaches showing the impact of maritime climate changes (Alfredini et al. 2008), wave climate and tidal forcing (Alfredini et al. 2012, 2013 and 2014 , Fournier 2012). Figure 1. Santos Port site location The long term tidal level variability assessment of CODESP, the Santos Dock Company, from 1940 until 2007 and of the Santos Pilots-Zenith, 2008 until now, showed the possibility to have exactly four lunar declination periods https://www.w3.org/1998/Math/MathML"> ( 1940 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - 2014) of 18.61 years each one (Fig. 5). The forecasting trends of Higher High Water (HHW) and Lower Low Water (LLW) depend largely upon the meteorological tide, beyond sea level rise (Alfredini et al. 2013). Comparing with PIANC 2014 a, the tidal trend of Santos Port is similar to the moderate trend of the UK recommendations, meaning a mean sea level rise around https://www.w3.org/1998/Math/MathML"> 50 c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> from 1950 until 2050 , and https://www.w3.org/1998/Math/MathML"> 110 c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> from 1950 until 2100 . For HHW and LLW the trends are similar, as showed in Figure 5 . Hence, in the future dramatic changes in tidal range and in the currents would not occur. Based upon water speed surveys, it was possible to calibrate and validate the mathematical hydrodynamical model of the tidal current of Santos Bay using the Mike 21 software (Baptistelli et al. 2008). Figures 2 and 3 show charts for a spring tide in July. The flood and ebb conditions are maxima, respectively. It is possible to observe that the maximum current velocities reaches values around 0.8 knots (deep averaged) in the estuarine port area. In equinoctial spring tides, the values may arrive up to 2 knots. However, in Santos Bay the tidal current velocities are roughly half those figures. An assessment of the characteristics and historical frequency of extreme storm events employed the long-term (Jan https://www.w3.org/1998/Math/MathML"> 1 st 1980 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - August https://www.w3.org/1998/Math/MathML"> 6 th https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2012) a wave climate database (www.OndasdoBrasil.com). The database include definitions of significant wave height https://www.w3.org/1998/Math/MathML"> H m 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , spectral peak wave period https://www.w3.org/1998/Math/MathML"> T p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and spectral directions as required. Hindcasting deep-water was developed with the aid of the WaveWatch III, the third generation wave model, and was calibrated with Topex Satellite data along Brazilian coastline, and subsequently validated with a directional sea buoy. The deep-water wave climate transferred to shallow water, in the Santos Bay showed the rose in Figure 6 (Fournier 2012). The statistical assessment of extreme wave considering a lognormal fitting gives the following significant heights estimated for a 100 years recurrence period: Upper Estimate: https://www.w3.org/1998/Math/MathML"> 8.92 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Average Estimate: https://www.w3.org/1998/Math/MathML"> 7.94 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Lower Estimate: https://www.w3.org/1998/Math/MathML"> 6.96 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Statistically, for a lifespan of 100 years and one recurrence period of 100 years, the probability of occurrence of these numbers is https://www.w3.org/1998/Math/MathML"> 63 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In the immediate future, the Port of Santos aims to receive Post Panamax Plus https://www.w3.org/1998/Math/MathML"> 5 th https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> generation container vessels) 9,000 TEUs with https://www.w3.org/1998/Math/MathML"> L p p : 335 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; B : https://www.w3.org/1998/Math/MathML"> 46.00 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and T: https://www.w3.org/1998/Math/MathML"> 15.00 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . These vessels will require a channel depth of https://www.w3.org/1998/Math/MathML"> - 17.0 m ( C D ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Huge amounts of capital dredging, maintenance dredging and some operations should be cancelled, especially during April to September, period of the highest waves (Alfredini 2013). The other issue is about the width of two-way channel of https://www.w3.org/1998/Math/MathML"> 220 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , suitable for Panamax vessels, but would be better at least https://www.w3.org/1998/Math/MathML"> 315 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (equal to 6.8 times the beam) to accommodate vessels Post Panamax Plus and an appropriate enlargement of the curve (Alfredini 2013). The last issue to consider relates to the channel's curvature radius presently set at https://www.w3.org/1998/Math/MathML"> 1800 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Fig. 1). It is small for the Panamax vessels and too small for the Post Panamax Plus. Without tugboats aid, it would have to be redesigned to at least https://www.w3.org/1998/Math/MathML"> 3300 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , unless if the use of tugboat would begin in the Outer Access Channel. That curve is the most accreted area of the Outer Access Channel due to the longshore sand transport along Santos beaches (Alfredini 2013). 38. THE SEAWARD CONCEPTUAL PLANNING PHASE 1 Considering the necessity to enlarge the geometric dimensions (depth, width and radius) of the Outer Access Channel of Santos Port with the purpose of navigating in a two way with Post Panamax Plus vessels of 9000 TEUs, training walls are the best engineering solution (Alfredini 2013). This solution is present in the Master Plan of Santos Port proposed in the 1960 decade and it is the Phase 1 of the Conceptual Planning for the Offshore Port. Figure 2. Tidal currents chart in the maximum spring tide flood current in July https://www.w3.org/1998/Math/MathML"> 21 st 2005 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Figure 3. Tidal currents chart in the maximum spring tide ebb current in July https://www.w3.org/1998/Math/MathML"> 21 st 2005 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Figure 4. Throughput trends forecasting for Santos Port. igure 5 . Santos Port annual tidal level variability from 1940 antil 2014. Figure 6. Wave height rose in Santos Bay (1980 until 2012). Considering an increasing of https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the offshore extreme waves, as suggested in PIANC (2009) due to the climate changing, the design value of significant wave suggested for the training walls heads is https://www.w3.org/1998/Math/MathML"> 9.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , according to the upper estimate previously mentioned. Considering the sea level rise, the HWN (High Water Neap) and the wave uprush, the altitude of the crest of the training walls heads would be around https://www.w3.org/1998/Math/MathML"> + 13.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Brazilian Altimetry Datum) with an armor of precast concrete blocks, or https://www.w3.org/1998/Math/MathML"> + 8.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , using deflector concrete cap to avoid overtopping the crest level. A rubble mound structure, such as the two training walls with a total length of https://www.w3.org/1998/Math/MathML"> 9 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Fig. 7) will provide a solution. Significantly reducing the OPEX requirements (dredging maintenance cost), and redesigning the adequate channel dimensions to depth https://www.w3.org/1998/Math/MathML"> - 17.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (CD), the channel would be suitable for the larger vessels. As shown in Figure 7, the Western Jetty will trap the longshore sand transport along the beaches' surf zone, a natural nourishment, reducing the Outer Access Channel sedimentation. Indeed, the present annual dredging rate, with depth https://www.w3.org/1998/Math/MathML"> - 15.0 m ( C D ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the channel is around 2.5 million https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The training walls will provide a sheltered access channel. That process will enhance the coastal defenses against flooding due to sea level rise, storm surges, increasing the coastal resilience against these phenomena. Indeed, in the last decade increased the frequency of inundation episodes in the areas of Santos municipality. 39. THE SEAWARD CONCEPTUAL PLANNING PHASE 2 Figure 8 shows the layout for Seaward Conceptual Planning Phase 2 for Santos Offshore Port. The best area for this expansion is the southeastern extreme of Santos Bay, where the average depth is around https://www.w3.org/1998/Math/MathML"> 14.5 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (CD). However, it will be necessary to provide an external jetty of https://www.w3.org/1998/Math/MathML"> 7.5 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> length to protect the berths from the waves ESE to SSW (see Fig. 6). The maintenance of a deeper access channel will enlarge the Phase 1 of Western Jetty more https://www.w3.org/1998/Math/MathML"> 4.5 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which will protect additionally the beaches westward, growing their resilience against the increasing frequency and impact of storm surges foreseen. At last, the Phase 1 of Eastern Jetty will be enlarged with more than https://www.w3.org/1998/Math/MathML"> 3.5 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , used for a coastal closure and providing a reclamation land. For the training walls crest level it will be used the same figures explained in item 3 . Considering the sea level rise for HWN (High Water Spring) and the residual wave, the quay apron platform level will be around https://www.w3.org/1998/Math/MathML"> + 4.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Brazilian Altimetry Datum). The storage yards retro-areas will be reclaimed at the same level. The Seaward Conceptual Planning Phase 2 for Santos Offshore Port will be the construction of the deep berths for the following vessels type: Triple E - Ultra Large Container - up to 22,000 TEUs with https://www.w3.org/1998/Math/MathML"> L pp : : 470 m ; B : 59.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> : 17.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . NPX - New Panamax - up to 15,000 TEUs with https://www.w3.org/1998/Math/MathML"> L p p : 400 m ; B : 56.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> T : 16.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Post Panamax Plus - up to 9,000 TEUs with https://www.w3.org/1998/Math/MathML"> L pp https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> : https://www.w3.org/1998/Math/MathML"> 335 m ; B : 46.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> T : 15.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Ore Capesize - up to 150,000 DWT with https://www.w3.org/1998/Math/MathML"> L pp : 276 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> m ; B : 44.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> T : 17.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Suezmax for ethanol - up to 150.000 DWT with https://www.w3.org/1998/Math/MathML"> L pp : 270 m ; B : 49.5 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> T : 17.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Considering the larger draught of https://www.w3.org/1998/Math/MathML"> 17.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , it will be necessary to provide the depth of https://www.w3.org/1998/Math/MathML"> - 19.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (CD) for the access channel extension of Phase 2 . Figure 8 . Schematic location of Seaward Planning Phase 2 for Santos Offshore Port. The exact geometry of these jetties and the quays' alignment will be dependent of an accurate study of fill and dredging volumes, associated with the retroarea necessary, according to the cargo to be handled. The Seaward Conceptual Planning Phase 2 for Santos Offshore Port will follow the sustainable port concept (PIANC 2014b), including the climate adaptation. 40. CONCLUSIONS It is possible, based upon the international guidelines suggested by PIANC (2009,2014a and 2014b), propose the Seaward Conceptual Planning for Santos Offshore Port considering the future sea level rise and wave climate that will be predictable until the end of this century. Indeed, the tidal database of Santos Port is one of the longest and confident in the Southern Hemisphere and its sea level rise trend is similar to the UK recommendations for a moderate scenario of climate changes. Hence, this validation gives the best estimative for altimetry design parameters for the jetties crest and retroarea. The estimative of the wave climate has considered a well-known hindcasting technique, based upon the last three decades to forecast the 100 years' design wave, which is statistically justified. Considering the increasing wave heights due to the climate changing scenario, the recommendation is to use the upper estimate. 41. ACKNOWLEDGEMENTS This paper has the financial support of CAPES, Human Resources Improvement Agency of Brazilian Government. The authors also thank the support of São Paulo University, CODESP, Santos Pilots, Zenith, Baird & Associates Coastal Engineers Ltd. 42. REFERENCES Alfredini, P., Arasaki, E. & Amaral, R. F, 2008. Mean sea level rise impacts on Santos Bay, Southeastern Brazil Physical modelling study. Environmental Monitoring and Arsessment vol.144: 377-387. Amsterdam: Springer. Alfredini, P., Arasaki, E., Pezzoli, A., Arcorace, M., Cristofori, E. I. & Sousa Jr., W. C. 2014. Exposure of Santos Harbor Metropolitan Area (Brazil) to wave and storm surge climate changes. Water Quality, Exposure and Health vol. 6, Issue 1-2, pp 73-88. Springer Netherlands. Alfredini, P., Arasaki, E., Pezzoli, A., Fournier C. P. 2013. Impact of climate changes on Santos Harbor, São Paulo State (Brazil)...In A. Weintrit & T. Neumann (Org.), The International Journal on Marine Navigation and Safety of Sea Transportation TransNav vol, 7(4), London: CRC Press/Balkema. Alfredini, P., Pezzoli, A., Cristofori, E. I., Dovetta, A. & Arasaki, E. 2012. Wave and tidal level analysis, maritime climate changes, navigation's strategy and impact on the coastal defences - Study case of São Paulo State coastline harbour areas. Geophysical Research Abstracts: vol. 14, EGU2012-10735. Vienna. Baptistelli, S. C., Harari, J. & Alfredini, P. (2008). Using "Mike 21 " and "POM" for numerical simulations of the hydrodynamics in Baixada Santista region (São Paulo, Brazil). Afro-America Global Sea Level Observing System News: 12 (1). Fournier, C. P. 2012. Ondas Santos. Workshop Molhes GuiasCorrentes na Barra de Santos - O futuro da acessibilidade maritima ao Porto. Santos: Associação de Engenheiros e Arquitetos de Santos. Moreira, A. S. 2009. Sistema de informą̧̃es de indicadores do modelo porto concentrador de carga. PhD Thesis in Hydraulic Engineering, presented to the Hydraulic Department of the Polytechnic School, University of São Paulo, São Paulo (Brazil) PIANC - The World Association for Waterborne Transport Infrastructure 2009. Waterborne transport, ports and waterways: A review of climate change drivers, impacts, responses and mitigation. Bruxelles: EnviCom - Task Group 3 Climate Change and Navigation. PIANC - The World Association for Waterborne Transport Infrastructure 2014a Countries in Transition (CIT) Coastal Erosion Mitigation Guidelines. Bruxelles: Cooperation Commission (CoCom), PIANC Report 123 . PIANC - The World Association for Waterborne Transport Infrastructure 2014b Sustainable Ports A Guide for Port Authorities. Bruxelles: IAPH EnviCom Report Working Group 150, PIANC Report 150 . Mathematical Modeling of Wave Situation for Creation of Protective A. Gegenava, I. Sharabidze & A. Kakhidze Batumi Maritime Academy, Batumi, Georgia Abstract shows that the main factor, which influences upon the level of safety of navigation in water area of Port of Kulevi is heavy sea. The analysis of wave conditions was conducted for the provision of the necessary level of safety of navigation as well as the provision of effective and safe maintenance of hydrotechnical constructions. The automatical meteorological station which is a part of Port of Kulevi VTS equipment gave possibility of every day (per each 30 minutes) keeping of the wind condition (direction, speed, maximal and minimal indicators). The complex of measures of Port of Kulevi water area protection was worked out on the basis of that analysis. Abstract The presented paper continues the previous two papers - "New Black Sea Terminal of Port Kulevi and it Navigating Features" and "Analysis of Hydrometeorological Characteristics in Port of Kulevi Zone", which was published in "8th and 9th INTERNATIONAL NAVIGATIONAL SYMPOSIUM ON MARINE NAVIGATION AND SAFETY OF SEA TRANSPORTATION. GDYNIA, POLAND, 2009 and https://www.w3.org/1998/Math/MathML"> 2011 ' ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and deals with the aspects of safety navigation provision in Port Kulevi by means of conduction of mathematical modelling of wave situation for creation of protective hydrotechnical constructions in port Kulevi. As it was said in the previous papers, the port of Kulevi from the point of view of hydrometeorological condtions is a difficult one. The influence of prevailing wind directions - East and West, constant sea and curents of river Khobi, as well as the absence of the special protective hydrotechnical constructions allows the waves and sediments from the rivers Rioni and Khobi to enter to the channel. This paper presents the matmatical modeling of wave situations in different variants of protective measures for creation of protective hydrotechnical constructions which can be conducted in Port Kulevi having the aim the decreasing of hydro meteorological conditions to provide the safety navigation. 42.1. Theoretical justification Mathematical modeling was carried out using the theory of frequency-angular spectrum using the coefficients of surface and of bottom friction. To describe the fields of excitement uses the concept of frequency-angular spectrum https://www.w3.org/1998/Math/MathML"> E ( σ , θ , x , y , t ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , where: σ,θ - frequency and angular coordinates; https://www.w3.org/1998/Math/MathML"> x , y , t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - horizontal coordinates and time Appropriate equation for the determination of E is given by the law of conservation of energy: https://www.w3.org/1998/Math/MathML"> ∂ ∂ t N + ∂ ∂ x c x N + ∂ ∂ y c y N + ∂ ∂ θ c ω N + ∂ ∂ θ c θ N = S ω https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where, https://www.w3.org/1998/Math/MathML"> N = E / ω https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - density of wave action; Magnitudes, https://www.w3.org/1998/Math/MathML"> C X , C Y , c ω , c θ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - transport velocity along the appropriate spatial and frequency-angular coordinates. For numerical solution of equation (1) is applied a modified version of the model, in which the source function is defined as https://www.w3.org/1998/Math/MathML"> S = S in + S nl + S wc + S bf + S dib https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , where: Sin - the source of generation of waves by the wind; https://www.w3.org/1998/Math/MathML"> S n l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - non- linear interactions spectral harmonics; https://www.w3.org/1998/Math/MathML"> S w c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - dissipation of the energy due to the caving of the wave crests; Sbf - dissipation of the energy due to of bottom friction; Sdib - caving waves on the critical depths. In the original version the source of wave generation https://www.w3.org/1998/Math/MathML"> S in - is determined by assuming that the https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> friction coefficient https://www.w3.org/1998/Math/MathML"> C d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> only depends on the wind speed. Solution of problem (1), (2) makes it possible to obtain estimates a number of spectral wave characteristics, in particular the significant wave height and root mean square wave height. A characteristic feature of this model is the use of the coefficients of surface and of the bottom friction, characteristic only of the area of Kulevi port. 42.2. Coefficient of surface friction In most cases, the modeling of wind flows coefficient of surface friction is assumed constant or linearly dependent on wind speed. A more realistic approach is based on the theory of the boundary layer. Under the assumption that the profile of the wind speed near the surface of the sea has a logarithmic form, the value of Cd determined by the expression https://www.w3.org/1998/Math/MathML"> C d = K 2 / 1 n 2 z / z 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where: https://www.w3.org/1998/Math/MathML"> k = 0.4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - Karman constant, https://www.w3.org/1998/Math/MathML"> z = 10 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and Z0 - sea surface roughness parameter characterizing the hydrodynamic properties of the underlying surface and determines the mode of turbulent mixing at the interface of atmosphere-sea. 42.3. Coefficient of bottom friction Under the assumption of logarithmic depending profile current speed near the -of bottom for the coefficient of bottom friction https://www.w3.org/1998/Math/MathML"> C b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> we have expression similar to (3): https://www.w3.org/1998/Math/MathML"> C b = K 2 / 1 n 2 ( z / z 0 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where: https://www.w3.org/1998/Math/MathML"> Z b b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - parameter roughness of bottom surface; z - distance from the bottom up to the point at which determined the coefficient of friction. 43. TERMS OF MODELLING The main physiographic characteristics that influence the wave processes are wind strength, direction, which determines the overclocking wave (the distance at which the wave is generated the energy), the duration of the wind and the depth terrain. Calculations were carried for dangerous wind conditions the western part. For the initial condition takes steady excitement with certain characteristics, which were set at the boundary investigated area. The boundaries were taken as liquid boundaries flow (boundary conditions) with the calculated oceanographic tables wave characteristics established excitement (the period and wave height). At the NW wind overclocking length was set 550 km, at https://www.w3.org/1998/Math/MathML"> S W - 180 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , at https://www.w3.org/1998/Math/MathML"> W - 1,100 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The depth of area was set field of depths obtained by conversion data hydrographic observations. Depth values are tied to the local reference system (local coordinates) and interpolated on a computational grid https://www.w3.org/1998/Math/MathML"> 80 x 40 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> nodes in increments of 50 and 75 meters respectively. The results of modeling are shown in Fig. 1-3. Figure 1. Direction of wind https://www.w3.org/1998/Math/MathML"> - N W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , speed of wind https://www.w3.org/1998/Math/MathML"> - 30 m / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Figure 2. Direction of wind - W, speed of wind https://www.w3.org/1998/Math/MathML"> - 30 m / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Figure 3. Direction of wind - SW, speed of wind https://www.w3.org/1998/Math/MathML"> - 30 m / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 44. ANALYSIS OF MODELLING The analysis shows that the largest area of maximum wave fields is observed from West and South-West directions. As a result of this work on mathematical modelling have been analysed several options of protective hydrotechnical constructions. A characteristic feature of the chosen protective hydrotechnical construction (see fig. 4) is the output of the extremities of protective hydrotechnical constructions into natural depths https://www.w3.org/1998/Math/MathML"> 7 - 8 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , resulting entry of the sediment from the river Rioni in the approaching canal. Approximate volume - about 4050 thousand cubic meters per year. The remaining sediments from the river Rioni will form the beach. Extremities of protective hydrotechnical constructions are located on a natural depth of the order of https://www.w3.org/1998/Math/MathML"> 7 - 8 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Dimensions of protective hydrotechnical construction given in table 1. Figure 4. Scheme of protective hydrotechnical construction. 45. MODELLING OF WAVE SITUATION WITH Have been selected initial wind conditions: wind North-West, West and South-West directions at the speed of https://www.w3.org/1998/Math/MathML"> 30 m / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The results of mathematical modeling represented of the fields in the form of wave loads in Fig. 5-7. Figure 5. Wawe loads (NW), speed of wind https://www.w3.org/1998/Math/MathML"> - 30 m / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Figure 7. Wawe loads (SW), speed of wind https://www.w3.org/1998/Math/MathML"> - 30 m / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 46. CONCLUSIONS From the positions of safety of navigation, the prospects development of port, the economic feasibility and efficient operation of protective hydrotechnical constructions preferred is protective hydrotechnical construction shown in the figure 4 . Results of modelling show: At the north-west wind speeds up to https://www.w3.org/1998/Math/MathML"> 30 m / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in port aquatory will go wave height not exceeding https://www.w3.org/1998/Math/MathML"> 2,0 - 0,8 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , at the berths - no more https://www.w3.org/1998/Math/MathML"> 0,4 - 0,2 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; At the westward wind speeds up to https://www.w3.org/1998/Math/MathML"> 30 m / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in port aquatory will go wave height not exceeding 2,0 https://www.w3.org/1998/Math/MathML"> 0,8 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , at the berths - no more than https://www.w3.org/1998/Math/MathML"> 0.5 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; At the south-west wind speeds up to https://www.w3.org/1998/Math/MathML"> 30 m / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in port aquatory will go wave height not exceeding https://www.w3.org/1998/Math/MathML"> 1.0 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , at the berths - no more https://www.w3.org/1998/Math/MathML"> 0,2 - 0,1 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; Wave loads on the hydrotechnical constructions at rated wind speed of western rhumb https://www.w3.org/1998/Math/MathML"> 30 m / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> will not exceed https://www.w3.org/1998/Math/MathML"> 0.5 t / m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; At calculations of the wave loads recommended to take speed of winds from the western rhumb https://www.w3.org/1998/Math/MathML"> 33 m / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 47. REFERENCES Georgian Government Order N57 on "Establishment of ships movement separating schemes, sea corridors and special sea regions in Georgian territorial Water area". Tbilisi, 2014; Maritime Transport Agency of Georgia, Director Order on approval of Port Rules, №019. Batumi, 2013; Dzhaoshvili S. "Hydrologic-morphological processes in mouth zone river Rioni and their anthropogenesis changes". Water resources, w. 25 , NQ2, 1998; Varazashvili N. "Geological processes and the phenomena in a zone of construction of sea hydraulic engineering constructions and actions on improvement of a coastal situation". Engineering geology (excerpt). Academy of Sciences the USSR. Moscow, 1983 ; Dzhaoshvili S. "New data about beach formed sediments of a coastal zone of Georgia". Water resources (excerpt). Academy of Sciences the USSR. Moscow, 1984; Materials of supervision over elements of a hydrometeorologcal mode for the period 1971-1999. (Information of Poti mouth stations); Bettes P. "Diffraction and refraction of surface waves using finite and infinite elements". Numerical Meth. London, 1997; Bach H., Christiansen P. "Numerical investigations of creeping waves in water theory". ZAMM. New York, 2004; Mathematical modelling of hydrological characteristics in the port of Kulevi. LLC "Anchor". Kulevi, 2009; Black Sea Terminal of Port Kulevi. https://www.kulevioilterminal.com; Gegenava A, Varshanidze N, Khaidarov G. "New Black Sea Terminal of Port Kulevi and it Navigating Features". TransNav 2009, Gdynia, 2009; Gegenava A, Khaidarov G. "Analysis of Hydrometeorological Characteristics in Port of Kulevi Zone". TransNav 2011, Gdynia, 2011. The Northerly Summer Wind off the West Coast of the Iberian Peninsula N. Rijo & A. Semedo Escola Naval-CINAV, Lisbon, Portugal D.C.A. Lima, P. Miranda, R.M. Cardoso & P.M.M. Soares Instituto Dom Luiz, University of Lisbon, Lisbon, Portugal Abstract Winds are a natural hazard for mariners and for offshore infrastructures. In spite of having been used as a propulsion system throughout times, nowadays it can be a source of danger in extreme situations. High wind speeds can also represent an economic driver, since, on the one hand, wind energy can be harvested from off-shore wind farms, but on the other hand fishing activity or, for example, off-shore fish farms are affected. The predominant winds in the North Atlantic (the Westerlies) have a basin-wide scale, and are highest during winter. During summer, when the large scale forcing is weaker, mesoscale and local wind features prevail. That is the case of coastal jets. During summer the Iberian Peninsula is under the effect of the semi-permanent Azores High and of a thermal low pressure system in-land. This synoptic pattern drives a seasonal northerly wind along the west coast of the Iberian Peninsula. This regional wind is an example of a coastal jet. An insight on the climatology of the Iberian Peninsula coastal jet (IPCJ) is presented, based on a regional reanalysis produced with the WRF mesoscale model for the period 1989-2007. It is shown that although the IPCJ are more frequent in the south area of the west coast of Iberia, in the north area coastal jets are stronger (with higher wind speeds). The dynamic structure of the IPCJ is studied through the analysis of a strong summer IPCJ event along west coasts of Galicia and north of Portugal (at https://www.w3.org/1998/Math/MathML"> 3 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> horizontal resolution). This case study was identified in vicinity of Aveiro on 14 th July 2002 at 1900 local time. 48. INTRODUCTION The regional climates along the mid-latitude western continental Coastal regions are affected by the ocean and atmospheric circulations and their interactions. At these regions, mostly in summer, the contrast between the cold oceanic waters and the warm land are strong, which is fundamentally responsible for the existence of a coast parallel wind designated as the coastal low-level jets (CLLJ) or as "coastal Jets". In spite of being a mesoscale feature, CLLJ occurrences have a typical large scale synoptic forcing behind them, characterized by a high pressure systems over the ocean and a thermal low in-land. This pressure gradient is responsible for driving a coastal parallel wind pattern along the coast. For that reason CLLJ occurrence regions coincide with cold equator-ward eastern boundary currents, located along the east flanks of the atmospheric semi-permanent high pressure cells (Winant et al. 1988) in the mid-latitudes. During summer these coast parallel winds features are responsible for upwelling processes, bringing deep cold nutrient-rich water to the shelf and to the surface (Vallis 2012). As a result sharp temperature and pressure gradients develop at the coast (Chao 1985), and consequently an intensification of coastal winds occur, which means that CLLJ are synoptically forced but mesoscale intensified. CLLJ have a small vertical extend with wind speed maxima (jet core) located at low altitudes, of the order of hundreds of meters above sea level (ASL), confined at the marine atmospheric boundary layer (MABL) height (Beardsley et al. 1987, Burk and Thompson 1996 , Söderberg and Tjernström 2002). The MABL is capped by a sharp temperature inversion, which is strengthened by the warm inversion, which is strengthened by the warm surface, that cools in contact with the low sea surface temperature (SST) due to upwelling. The horizontal extent of CLLJ can exceed hundreds of kilometres, limited in by the Rossby radius of deformation (Winant et al. 1988, Garreaud and Muñoz 2004, Ranjha et al. 2013, Soares et al. 2014). The presence of coastal topography, capes, and headlands, can result in additional local enhancement of the wind speed, and changes in the flow direction if the mountains are higher than the sloping capping inversion of the MABL. The crosscoast flow is blocked and the wind becomes semigeosptrophic. In these situations the flow is channelled, and the wind speed increases even more at the coast (Winant et al. 1988 , Burk and Thompson 1996, Tjernström and Grisogono, 2000). Coastal jets are essentially a summer phenomena, which occur when the synoptic pattern prevail. Their occurrence, as mentioned before, is strongly linked to upwelling and to low SST along the coast. The major upwelling areas, coinciding with the CLLJ areas (Ranjha et al. 2013) are where the most productive regions of the World Ocean in terms of fishing: about https://www.w3.org/1998/Math/MathML"> 17 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the worldwide fish captures take place along the coastal upwelling regions (Pauly and Christensen 1995), which in turn cover less than https://www.w3.org/1998/Math/MathML"> 1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the world ocean area. The regional climates of the mid-latitude western continental areas are related CLLJ and to the associated cold SST. The low SST at the coast lowers the evaporation over the ocean, and the strong coast parallel winds substantially reduce the advection of marine air in-land. For this reason the atmospheric water vapour content in-land is low and some of the mid-latitude western coastal regions are arid or desert regions (Warner 2004). Due to shear (mechanically driven) turbulence the MABL at the coast in CLLJ areas is usually stable. After some consecutive days of coastal jet occurrences, if the synoptic forcing changes and favours the advection of warm moist air towards the along coast low SST areas, coastal fog or stratus clouds can occur (Tjernström and Koracin 1995, Burk and Haak 1999). Since CLLJ have an impact on cloud cover, visibility, SST, and wind structure in coastal areas, their importance for mariners, fishing, and shipping activity can be considerable. Hence a more in deep knowledge of this wind feature is of paramount importance. The Iberian Peninsula Coastal Jet (IPCJ) is an example of a CLLJ, developed mostly during the summer season, due to the effect of the semipermanent Azores High in North Atlantic sub-basin, and to the presence of a thermal low pressure system inland over the Iberian Peninsula. This synoptic pattern drives a seasonal northerly wind along the west coast of the Iberian Peninsula often called the Nortada (Lopes et al. 2009). The climatology of the Iberian Peninsula CLLJ was recently presented by Soares et al. (2014). They have found that, in of spite not being as prevalent as other coastal jets (Ranjha et al. 2013, 2014), during summer (particularly in July) it has frequencies of occurrence of the order of https://www.w3.org/1998/Math/MathML"> 34 - 35 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In this study we present a detailed climatology of the IPCJ as well as an insight the mesoscale structure, spatial variability and temporal characteristics of the IPCJ, complementing the study of Soares et al. (2014). The results were obtained through the Weather Research and Forecasting (WRF) model downscaling data produced in Soares et al., 2012, at https://www.w3.org/1998/Math/MathML"> 9 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> resolution, for a period 1989 to 2008 . A detail analysis of a IPCJ case study (at https://www.w3.org/1998/Math/MathML"> 3 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> resolution) along the west coasts of Galicia and north of Portugal, occurred in vicinity of Aveiro on 14th July 2002 at https://www.w3.org/1998/Math/MathML"> 1900 L t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is also presented. 49. DATA AND METHODOLOGY 49.1. Filtering algorithm The calculation of the occurrence of the CLLJ, and in particularly the IPCJ, follows the CLLJ detection algorithm proposed by Ranjha et al. (2013). This algorithm is based on the inspection of the vertical wind speed and temperature profiles. According with this criteria the IPCJ is considered to occur when: The height of the jet maximum (maximum wind speed) is within the lowest https://www.w3.org/1998/Math/MathML"> 1 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the vertical; The wind speed maxima is at least https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> higher than the wind speed at the surface; The wind speed above the jet maximum decreases to below https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the wind speed at the surface (i.e. a https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> falloff) before reaching https://www.w3.org/1998/Math/MathML"> 5 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> above its maximum; The temperature at the jet maximum height is lower than the temperature at two model levels above it (inversion detection criterion); and These criteria were then used to scan the regional reanalysis at each grid point and to identify the locations and occurrences of coastal jets. 50. 2.2 Regional reanalysis and case study simulations A climate simulation (regional reanalysis), produced with the WRF model (version 3.1.1), covering the period 1989-2007, is used in the present study (Soares et al. 2012), namely the results from the innermost domain, with a https://www.w3.org/1998/Math/MathML"> 9 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> horizontal resolution. The WRF model (Skamarock et al. 2008) is a non-hydrostatic mesoscale model, suitable for simulations at a wide range of scales, with a large number of available options concerning the model core and its physical parameterizations, making it appropriate for weather forecasting, and mesoscale meteorological studies. More recently the WRF model has also been extensively for dynamical downscaling in regional climate studies. The regional reanalysis used here was produced by downscaling the ERA-Interim global reanalysis from the European Centre for Medium-Range Weather Forecasts (ECMWF). A complete and more detailed description of the model set-up can be found inSoares et al. https://www.w3.org/1998/Math/MathML"> ( 2012 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Cardoso et al. https://www.w3.org/1998/Math/MathML"> ( 2013 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and Soares et al. (2014), where the simulation results were validated for inland maximum and minimum temperatures and precipitation, and to marine surface wind speeds, showing a good agreement with observations. The case study presented here used, as boundary and initial conditions, data from the regional reanalysis at https://www.w3.org/1998/Math/MathML"> 9 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> horizontal resolution mentioned above. These boundary and initial conditions were used to force an inner domain at https://www.w3.org/1998/Math/MathML"> 3 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> resolution (see Figure 1). The case study WRF simulation was parameterized with 49 vertical levels, placing roughly 20 vertical levels in the boundary layer, with the lowest model sigma level at approximately https://www.w3.org/1998/Math/MathML"> 10 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of height and model top at https://www.w3.org/1998/Math/MathML"> 50 h P a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The lateral boundary conditions and SST were both updated every https://www.w3.org/1998/Math/MathML"> 6 h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , from the https://www.w3.org/1998/Math/MathML"> 9 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> regional reanalysis. The WRF model run was set to start at 0000 UTC July 10,2000 , and end at 0000 UTC July 19, 2000). Figure 1. (a) WRF domains used in the downscaling, from outermost to innermost domain with horizontal resolution of 9 km (black line) and https://www.w3.org/1998/Math/MathML"> 3 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (blue line), and (b) areas of statistical analysis, west coast strip (green line), and sub areas Al (dust analysis, west coast strip (green line), and sub areas AI (dust https://www.w3.org/1998/Math/MathML"> ( 41.132 N 9.42 W ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> b ( 38.436 N 9.71 W ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , respectively. 51. DETAILED CLIMATOLOGY OF THE A statistical analysis of the global occurrences of coastal jets was performed by Ranjha et al. (2013), and more recently the climatology of an IPCJ was presented by Soares et al. (2014). Their results showed two main areas of occurrence of the IPCJ along the west coast of Iberia. These areas are located south of Cape Finisterre, and south of Cape Roca, the west-most point of continental Europe. In complement of their study we have recomputed the frequencies of occurrence of IPCJ for a strip along the west coast of the Iberian Peninsula, and separately for each of the North (A1) and South (A2) areas, represented in Figure 1. The intra-annual variability of IPCJ occurrences and the mean wind speed, (mean monthly occurrences) for the west strip (Figure https://www.w3.org/1998/Math/MathML"> 2 a , b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) and for areas A1 (Figure 2c,d) and A2 (Figure 2e,f) are shown. The mean wind speed (ms-1), was computed at each grid point when jet occurs, at the height of the maximum wind speed (jet core). From the frequencies of occurrence it is clearly the seasonality of the IPCJ occurrence displaying the maximum values in the summer months, particularly in July. The geographical distribution of the IPCJ occurrence is also clear where area A2 (south) show the mean frequency of occurrence of the IPCJ highest (close to https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in July, i.e., 1 out of 3 days in that month comprises a coastal jet occurrence). In area A1 (north) the mean frequency of occurrence of the IPCJ is lower (slightly higher than https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> also in July, when the occurrences peak), but the wind speed, in July, at the jet height, is now higher than in the south area (close to https://www.w3.org/1998/Math/MathML"> 15 m s - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and about https://www.w3.org/1998/Math/MathML"> 12 m s - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in areas https://www.w3.org/1998/Math/MathML"> A 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> A 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , respectively). (a) (b) © (d) (e) (f) Figure 2 . Monthly mean (Jan to Dec) frequency of occurrence (%) histograms of IPCJ at (a) west strip, (c) area https://www.w3.org/1998/Math/MathML"> A 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and (e) area https://www.w3.org/1998/Math/MathML"> A 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and monthly mean (Jan to Dec) wind speed (ms-1), when jet occurs, at jet height (height of the maximum wind speed) at (b) west strip, (d) area Al, and (f) area A2. The analysis of the IPCJ characteristics of the Jetheight, wind speed maximum and direction for summer season are illustrated in figure 3 , for each area. From the wind rose plot (Figure https://www.w3.org/1998/Math/MathML"> 3 a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 3 b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) during summer months, in both areas, the predominant IPCJ wind direction at jet core is northerly https://www.w3.org/1998/Math/MathML"> ( 30 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to north-north-easterly https://www.w3.org/1998/Math/MathML"> ( 35 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> during JJA, almost parallel to the coast of Iberia. In transition months May, June and September the pattern is slight different, with wind directions slightly more easterly (not shown). The distributional pattern for the jet height (Figure https://www.w3.org/1998/Math/MathML"> 3 b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 3 d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) is similar in both areas, revealing that IPCJ occur at https://www.w3.org/1998/Math/MathML"> 200 - 400 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and have a wind speed maxima around https://www.w3.org/1998/Math/MathML"> 15 m s - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In area Al, nevertheless, the wind speed at the jet height in JJA is higher (wind speeds of the order of https://www.w3.org/1998/Math/MathML"> 20 - 24 m s - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> occurring https://www.w3.org/1998/Math/MathML"> ∼ 7 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the time; Figure https://www.w3.org/1998/Math/MathML"> 3 c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) than in areas A2 (Figure 3a). (b) (d) Figure 3. IPCJ statistics for summer (JJA), from WRF https://www.w3.org/1998/Math/MathML"> ( 9 k m ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , https://www.w3.org/1998/Math/MathML"> ( a , c ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> wind roses of mean wind speed (ms-1), when jet occurs, at jet height with prevail direction, and https://www.w3.org/1998/Math/MathML"> ( b , d ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the 2D histogram https://www.w3.org/1998/Math/MathML"> ( % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the jet height with the wind speed maxima (ms-1), for for area Al and https://www.w3.org/1998/Math/MathML"> A 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , respectively. 52. CASE STUDY ANALYSIS OF IBERIAN PENINSULA CLLJ The synoptic forcing behind the IPCJ occurrence is associated with the presence of the Azores High and a thermal low inland. A strong IPCJ event was identified at 14 th July 2000 , at 1400 UTC in vicinity of Aveiro. The synoptic pattern of this case study is characterized by a deeper high pressure system north of the Azores Islands, and consequently the zonal pressure gradient strait to central Iberia. (b) at lowest model level https://www.w3.org/1998/Math/MathML"> ∼ 10 m ( m s - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ), and (c) at jet height (ms-1) overlaid with wind direction, for July 14 th 2000 at 1900 (Lt). The contrast between land-sea temperatures associated with this zonal pressure gradient provides the baroclinic structures behind the IPCJ case study event as it is seen in Figure 4 a from the WRF simulations at https://www.w3.org/1998/Math/MathML"> 3 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> resolution. The horizontal wind speed maps for this case study simulation at the lowest model level https://www.w3.org/1998/Math/MathML"> ( ∼ 10 m A S L ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and at the jet height are represented in Figure https://www.w3.org/1998/Math/MathML"> 4 b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 4 c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , respectively. The close to surface wind speed pattern clearly shows the interaction of the flow with Cape Finisterre https://www.w3.org/1998/Math/MathML"> ∼ 43 ∘ N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and the flow acceleration southward, with an area of increased wind speed, in excess of https://www.w3.org/1998/Math/MathML"> 14 m s - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> west of Porto to Aveiro, in Portugal. At the jet height the wind speed increase is even better defined, with a jet core with wind speeds higher than https://www.w3.org/1998/Math/MathML"> 25 m s - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The https://www.w3.org/1998/Math/MathML"> ∼ 10 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> height surface wind speed pattern (Figure 4b) also shows a clear interaction of the flow with Cape Finisterre. Actually the flow is accelerated at Cape Finisterre, and this acceleration dominates the wind speed pattern along the whole west coast of Iberia. The changes in the wind direction, due to the topography effect are marginal. Nevertheless slight coast-ward wind direction changes can be seen, at the surface, south of Cape Finisterre, and south of Cape Roca and Cape St. Vincent. Wind speed maxima at jet height occurs at a considerable lower altitude https://www.w3.org/1998/Math/MathML"> ( ∼ 200 m ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . To investigate the vertical structure of the IPCJ the vertical across- and along-flow sections are show in Figures 5 through lines passing on key point a (Figure 1b). The potential temperature lines (isentropes) are also shown in these figures. From the cross-flow cross-section (Figure 5a) of case a high wind-speed core with wind speeds in excess of https://www.w3.org/1998/Math/MathML"> 25 m s - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , is clearly visible near the coast. The offshore extension of this coastal jet occurrence is considerable, with the jet core spanning to distances higher than https://www.w3.org/1998/Math/MathML"> 250 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> from the coast. The tilting of the isentropes towards the coast and the location of the jet core within the MABL capping inversion close to the coast are well defined, and typical of the characteristics of a CLLJ (Beardsley et al. 1987). This slope provides the thermal wind that forces the jet. The potential-temperature contours also show the capping inversion separating the warm air above and the relatively cool MABL at the surface. In the along-flow section shown in Figure https://www.w3.org/1998/Math/MathML"> 5 b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a very pronounced lowering of the MABL height (capping inversion) is seen. In less than https://www.w3.org/1998/Math/MathML"> 150 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the MABL height goes from more than https://www.w3.org/1998/Math/MathML"> 500 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to less than 200 m. As a consequence the wind speed, at the lower MABL height area south of Cape Finisterre, increases significantly through a Bernoulli like effect, where the flow is constrained to a considerably lower section. a) Figure 5. Case-study vertical cross-sections from WRF at https://www.w3.org/1998/Math/MathML"> 3 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for case study 1 on July 14th 2000 at 1900 (Lt) of (a) crosscoast and (b) along-coast (see lines in Figure 1) of wind speed (ms-1; shading contours) and potential temperature ( K; blue full lines). 53. DISCUSSION AND CONCLUSIONS A detailed climatology of the IPCJ along the west coast of Iberia is presented, based on a regional reanalysis (Soares et al. 2012), produced with the WRF model for the period 1989-2007, complementing the more general climatology from Soares et al. (2014). The IPCJ is a summer event whereas July is the month where the IPCJ is more frequent, and also the month where the wind speeds are higher. It is shown that although the IPCJ are more frequent in the south area of the west coast of Iberia (area A2), the coastal jets in the north area (area A1) are stronger, since the mean wind speed at the jet height is higher. The IPCJ occur in low troposphere in firs https://www.w3.org/1998/Math/MathML"> 200 - 400 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> A S L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which could be considered as a relative shallow coastal jet. The dynamic structure of the IPCJ is also studied trough the analysis of a particular IPCJ event. It is shown that the Cape of Finisterre is the main flow "accelerator" in the north of west coast of the Iberian Peninsula. It is analyzed the costal baroclinicity structures through the cross-coast pressure gradient and the land-sea temperature differences as a mesoscale mechanism behind the IPCJ event. The extension offshore of the IPCJ is shown to be of the order of https://www.w3.org/1998/Math/MathML"> 250 k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> although limited in the vertical extension to less than https://www.w3.org/1998/Math/MathML"> 400 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 54. ACKNOWLEDGEMENTS The work on this study was pursuit in the framework of the SHARE project, financed by the Portuguese Foundation for Science and Technology (FCT Fundação para a Ciência e Tecnologia, Portugal). All authors, with the exception of Nadia Rijo, are part of the SHARE project (RECI/GEO https://www.w3.org/1998/Math/MathML"> M E T / 0380 / 2012 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). Nadia Rijo is financed by the Portuguese Navy. 55. REFERENCE LIST Beardsley R. C., Dorman C. E., Friehe C. A., Rosenfield L. K., and Winant C. D., 1987: Local atmospheric forcing during the Coastal Ocean Dynamics Experiment 1: A description of the marine boundary layer and atmospheric conditions over a northern California upwelling region. J. Geophys. Res., 92, 1467-1488. Burk S. D., and Thompson W. T., 1996: The summertime lowlevel jet and marine boundary layer structure along the California coast. Mon. Wea. Rev., 124, 668-686. Burk S. D., Haack T., and. Samelson R. M, 1999: Mesoscale simulation of supercritical, subcritical, and transcritical flow along coastal topography. J. Atmos. Sci,56, 27802795 . Cardoso R.M., Soares P.M.M., Miranda P.M.A., Belo-Pereira M., 2013. WRF high resolution 627 simulation of Iberian mean and extreme precipitation climate. Int J. Climatol. 33, 2591-2608. DOI: 10.1002/ joc 3616 . Chao S., 1985: Coastal jets in the lower atmosphere. J. Phys. Oceanog., 15, 361-371. Garreaud R. D. and Munôz, R. C. 2005. The low-level jet off the west coast of subtropical South America: structure and variability. Mon. Wea. Rev. 133, 2246-2261. Lopes A., Oliveira S., Fragoso M., Andrade J. A., and Pedro P., 2009. Wind risk assessment in urban environments: the case of falling trees during windstorm windstorm events in Lisbon, Bio. And Nat. Hazards. International Scientific Conference, Pol'ana nad Detvou, Slovakia, ISBN 978-80228-17-60-8 Pauly D., and Christensen V., 1995. Primary production required to sustain global fisheries. Nature. 374,255-257. Ranjha R., Svensson G., Tjernstro" M., and Semedo A., 2013 . Global distribution and seasonal variability of coastal lowlevel jets derived from ERA-Interim reanalysis. Tellus A. 65,20412. Ranjha, R., Tjernstrōm M., Semedo A., and Svensson G., 2014: Structure and Variability of the Oman Coastal LowLevel Jet. Under review - Tellus A. Skamarock W. C., Klemp J. B., Dudhia J., Gill D. O., Barker D. M., and co-authors. 2008. A Description of the Advanced Research WRF Version 3. NCAR Tech. Note TN-468 + STR, 113 pp. Soares P. M. M., Cardoso R. M., Miranda P. M. A., Medeiros J., De, Belo-Pereira M., and co-authors. 2012. WRF high resolution dynamical downscaling of ERA-Interim for Portugal. Clim. Dyn. 39, 24972522 Soares P.M.M., R.M. Cardoso, Semedo A., Chinita M.J., Ranjha R., 2014: Climatology of the Iberia coastal lowlevel wind jet: weather research forecasting model highresolution results. Tellus A, 66,22377 Sôderberg S., and Tjernstrōm M., 2002: Diurnal Cycle of Supercritical Along-Coast Flows', J. Atmos. Sci. 59,26152624. Tjernstrồm M., and Koraciin D., 1995: Modeling the im act of marine stratocumulus on boundary layer structure. J. Atmos. Sci., 52, 863-878 Tjernstrōm M., and Grisogono, B. 2000. Simulations of supercritical flow around points and capes in a coastal atmosphere. J. Atmos. Sci. 57, 108-135. Vallis, G.K. 2012. Climate and the Oceans. Princeton University Press, p244. Warner T. T., 2004. Desert Meteorology. Cambridge University Press, Boston, MA, https://www.w3.org/1998/Math/MathML"> 595 p p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Winant C. D., Dorman C. E., Friehe C. A. and Beardsley R. C., 1988. The marine layer off northem California: an example of supercritical channel flow. J. Atmos. Sci. 45, 3588-3605. Emergency Group Decision-Making with Multidivisional Cooperation B. Wu, X.P. Yan & Y. Wang Intelligent Transport Systems Research Center (ITSC). National Engineering Research Center for Water Transport Safety. Engineering Research Center for Transportation Safety (ERCTS, MoE). Wuhan University of Technology, Wuhan, China J.F. Zhang Centre for Marine Technology and Engineering (CENTEC), Instituto Superior Técnico, Universidade de Lisboa, Portugal Abstract This paper aims to address the decision-making problem of emergency response for inland maritime accident. Since a maritime accident usually involves the behaviors of the ships in trouble and the ships passing-by, as well as the actions of the maritime authorities, the decision-making model should take into account the reactivity from multiple parties. Unlike the traditional group decision-making model which concerns more about the aggregation of opinions given by different experts, this paper focuses on the cooperative decision-making for experts from different departments. A cooperative group decision-making model is introduced after some basic assumptions are made. The presented model is then applied to a case study in the predefined scenario. Compared with the traditional group decision-making model, the combination option made by utilizing the cooperative model is more feasible and sensible for maritime accident. Finally, conclusions and remarks on the employed model are made and future research work is also proposed. 56. INTRODUCTION Group decision-making plays an essential role in choosing a best or compromise option, and has been a keen research topic in the field of multiple criteria decision-making (MCDM). Unlike MCDM, group decision-making focuses on the coordination of the experts when they make different or even conflict choices. This is very common because each expert may have their preferred orderings of the attributes. Moreover, the choice of a single expert may be not persuasive or feasible due to the inherent complexity or incomplete information in the process of decisionmaking. Thus group decision-making is widely used in order to integrate the experts' viewpoints and overcome limitation of individuals. One of the critical problems is how to deal with conflict information among experts in group decision making. This conflict may result from the following factors: (1) the experts assess the situation diversely due to preference orderings which are influenced by their educational backgrounds or professional experience such as the personalities, attitude and others. (2) The experts pay different extent of attentions to the attributes according to their own interests. For example, Maritime Safety Administration (MSA) closely concerns about the organization of search and rescue (SAR) and the safety of the whole waterway traffic, while ship operators focus on ship damage control and crew safety. (3) The high level of stress may influence the ability of decision makers. The accident may suddenly lead to entirely different results according to different intervention strategy, thus the decision makers should make the best choice in very short time. (4) The option made under uncertainty may be not be reliable and trustable. The uncertainty involves incomplete or imprecise information in emergency response. In order to overcome the vagueness and fuzziness, many effective and feasible methods have been introduced. To list some, Xu (2007) summarized that all group decision-making methods should involve the following information: (1) Collection of information about attributes weights and values; (2) weighted aggregation of the values across all attributes for each alternative to obtain an overall value; (3) Selecting the best alternative according to the orders of overall values. As for collecting information, linguistic variables (Xu, 2007) have been widely used to demonstrate the importance of linguistic variables. Specifically, Fuzzy rules (Ölçer & Ödabaşi 2005, Yeh & Chang 2009 , Yu et al., 2009), Evidential Reasoning (Xu et al., 2006), Utility Function (Huang et al., 2013) are the mostly utilized methods for illustrating the preference orderings, such as fuzzy preference relations (Fan et al., 2006), interval preference orderings (Liu et al., 2012,), Xu et al., https://www.w3.org/1998/Math/MathML"> 2006 , X u https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , 2013) and linguistic preference orderings (Dong et al., 2006). While in the aggregation of attribute values for incomplete information (Mateos et al., https://www.w3.org/1998/Math/MathML"> 2006 , X u https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et al., 2006, Xu, 2007), the group ranking problem can be roughly classified into two major approaches, the total ranking approach and the partial ranking approach (Chen & Cheng 2009). AHP is the well-recognized method for aggregation of attributes weights. But in most cases it cannot take the relationship among the attributes into consideration. To solve the problem, a Bayesianbased AHP method was proposed by Altuzarra et al. (2007). Moreover, the experts express their standpoint in a less standard way like AHP method. And the preference orderings are much more fuzziness and imprecise. Thus TOPSIS (Xie et al., 2011), Entropy (Xia & Xu 2012), distance-based (Cook, 2006) method were employed. As mentioned above, many powerful models have been proposed in group decision making. But when applying to the maritime accident response process, some issues have to be studied accordingly. There are multiple related departments in the process of decision making during a maritime accident. If the decision maker considers the problem from the perspective of his own department, it would give rise to inconsistency of execution. Thus all suggestions from other departments should be taken into consideration to obtain a highly uniformed SAR action sequence. Unfortunately, little research concerning about the multidivisional cooperation within group decision-making have been released. In order to address such problem, a multidivisional cooperation model was introduced in this paper. The rest of this paper is organized as follows. In Section 2, the maritime accident group decisionmaking is described and some pre-assumptions are presented. Section 3 introduces a coordinative group decision-making model including the definition of cooperative network, cooperative matrix and cooperative coefficient. Section 4 presents algorithm of cooperation model. And an experimental investigation was studied by employing the cooperation decision-making model to address the maritime accident problem in Section 5. Finally, some concluding remarks are drawn in Section 6. 57. PROBLEM STATEMENT AND Argumentation is a traditional but widely used method in group decision-making (Amgoud & Prade 2009). Through argumentation, the experts can easily express their preference orderings which enables others to easily get the key point. As information technology keeps on facilitating group decision-making in emergency response, the framework of group decision-making about emergent event based on network technology is proposed (Xie et al., 2011). Thus in order to apply the aforementioned framework to maritime accident case, the modeling and analysis of group decisionmaking plays a crucial role in emergency response based on network technology. In term of maritime accident emergency response for inland transportation ship, several departments would be involved according to different accidental type. In the group decision making, each department should fully understand the opinions of other departments and reach a strategy in common as quick as possible. Three related departments that are closely related with maritime emergency response were taken into consideration in this paper. The role of each department and their basic principles in decision-making are shown as follows. Ship owner department: it will try its best to damage control or risk migration by effective intervention methods. Thus normally they will not consider interests of other ships. But it should be noticed that the intervention methods may varies according to the navigational environment and the condition of ship. Ships passing-by: ships passing-by concern more about the delay time, it cannot be tolerated to stay in a long time owing to the influence of this incident. As many ships would be blocked which will make the channel congested, the interests of ship passing by should be carefully considered. Maritime safety administration (MSA): a department of governor in charge of waterway transportation safety and pollution prevention in China. In the perspective of MSA, the accidental ship should be properly disposed and the time of congestion would be as few as possible. According to the aforementioned principles, the decision options of each department are shown in Table 1. In this study, the option of accidental ship may influence the options of ship passing by and MSA. For example, if the accidental ship try to anchor in the channel, it would be difficult to navigate freely for ship passing by and the MSA would have to choose the one-way traffic or closure of navigation most of the time. An important thing to be noticed is that the options of departments would be changed along with the decision option of related department. The assumptions made in this study are as follows: (1) only one decision maker represent one involved department who is adequate for decisionmaking according to his knowledge. (2) All decision makers could understand the decision options proposed by other departments as well as make feasible determinations if the options are related. (3) The information obtained is sufficient for reasonable decision making. Thus the incomplete or imprecise information is negligible for this decision making model. 58. MODELING OF COOPERATIVE DECISION- MAKING Chen et al. (2010) proposed an emergency decision model with multiple stages, multiple objectives, and multidivisional cooperation, this model is really well-organized and the definitions of cooperation decision-making model were adopted and introduced in the subsections of this paper. 59. 3.1 Cooperative network In the traditional MCDM models, the experts from different departments make comments and decisions on the predefined criteria which is proposed by a certain department, in that case the options or measures in each department was assumed independent from each other. In practice, the options may be related or even conflict. For example, in a ship accident, from the viewpoint of the crews, they would take effective and loss-least option like anchoring in the channel; but from the perspective of ship of passing by, they would like the channel to be unobstructed so that they could navigate without unencumbered. Thus the two departments may conflict in this problem and the MSA should balance the standpoints from both departments and make the best option which could be carried out by cooperative decision-making model. As mentioned above, the emergency decisionmaking may involve many departments which may be independent from each other or not. The relationship between department j and department i can be denoted as https://www.w3.org/1998/Math/MathML"> A ( i , j ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , if the options of department j are independent from the options of department i, then https://www.w3.org/1998/Math/MathML"> A ( i , j ) = 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , otherwise https://www.w3.org/1998/Math/MathML"> A ( i , j ) = 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Only in the case of https://www.w3.org/1998/Math/MathML"> A ( i , j ) = 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> that each department should take the suggestions of other departments into consideration, through that the cooperative network was established and defined. 60. 3.2 Cooperative matrix The best option of each department is decided not only by the reliability (such as the possibility, expense and effectiveness) of the department itself, but also decided by the related department. Thus the cooperative matrix was proposed to consider the options made by other departments. Cooperative matrix W is introduced to illustrate the importance of the other departments. And https://www.w3.org/1998/Math/MathML"> W ( i , j ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is the cooperative coefficient of department i and department j. It could be easily obtained that the cooperative coefficient is 0 if the two departments are independent from each other. An essential theme to mention is that the cooperative matrix W is not always a symmetric matrix. This is very common in practice because the option of department i may influence department j but option of department j is independent from department i. 61. 3.3 Cooperative optimization model In the cooperative decision-making model, each department would take the other related departments options into consideration in the process of decisionmaking, from this perspective the cooperative decision option is a combination option of each department, and the goal of cooperative decision is to find a an optimization decision-making model which could balance the benefits and costs of the involving departments. The equation (1) is written as follows. https://www.w3.org/1998/Math/MathML"> S j x iai = W ( i , j ) s j x iai + ∑ AA ( t , j ) - 1 W ( t , i ) s j c o s e t x aia ∣ x iat https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The reliability of the combination option https://www.w3.org/1998/Math/MathML"> S , ( C ) , j = 1,2 ⋯ p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> under different criteria j is supposed to bé Maximum. Thus the case can be addressed as an optimization problem with p object. As https://www.w3.org/1998/Math/MathML"> S j ( C ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is a N dimensional vector, thus the optimization model can be achieved by computing the maximum norm. And the multiple objectives cooperative decisionmaking model can be illustrated as equation https://www.w3.org/1998/Math/MathML"> ( 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> m a x s 1 ( C ) , ⋯ s J ( C ) ⋯ , s p ( C ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> W ( , , j > 0 , ∀ i ∈ { 1,2 ⋯ , N } , j = { 1,2 ⋯ , N } https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 0 ≤ s j ωj x i , i ] ≤ 1 , ∀ i ∈ { 1,2 ⋯ , N } , j = { 1,2 ⋯ , p } https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 0 ⩽ x j ⋯ x ∞ , ∣ ∣ x k , k ⩽ 1 , ∀ i ∈ { 1,2 ⋯ , N } , j = { 1,2 ⋯ , p } , k = { 1,2 ⋯ , N } , A ( t , i ) = 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where https://www.w3.org/1998/Math/MathML"> s j ( C ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> means the norm of vector https://www.w3.org/1998/Math/MathML"> s j ( C ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> N-Number of departments; p - Number of evaluation criteria; https://www.w3.org/1998/Math/MathML"> R t = x i 1 , x i 2 … , x iki https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - Alternatives of department i, where k, means the number of alternatives of department i; https://www.w3.org/1998/Math/MathML"> C = x 1 al , x iai … , x NaN , ai ≤ ki https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - Combination option; https://www.w3.org/1998/Math/MathML"> s j self = x iai https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - Reliability of department i with the option j by itself; https://www.w3.org/1998/Math/MathML"> S j ofher = x iai ∣ x tat https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - Reliability of department t with the option j of department i when choosing https://www.w3.org/1998/Math/MathML"> x ta https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; https://www.w3.org/1998/Math/MathML"> s j = x iai https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - Reliability of other related departments with the option j of department i; https://www.w3.org/1998/Math/MathML"> s j ( C ) = s j x 1 a 1 , ⋯ , s j x ial ' ⋯ , s j x NaN - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Reliability of all departments with the combination option C under criteria j; https://www.w3.org/1998/Math/MathML"> S ( C ) = s 1 ( C ) , ⋯ , s j ( C ) , ⋯ s p ( C ) - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Reliability of all departments with the combination option c; https://www.w3.org/1998/Math/MathML"> W ( i , j ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - Cooperative coefficient of department i for department j; https://www.w3.org/1998/Math/MathML"> A ( i , j ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - The value is 1 If the department i is related with department j otherwise is 0 . 61.1. Simplification of cooperative model In order to simplify equation (2) where weights of the alternatives were unknown or uncertainty, the cooperative optimization model can be addressed in a liner weighted way. Specifically, each weight of alternative can be supposed as https://www.w3.org/1998/Math/MathML"> a ( i ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and this value can be decided either by the commander like MSA or by the information expressed by experts. Thus the cooperative optimization model could be simplified as equation (3). https://www.w3.org/1998/Math/MathML"> m a x ∑ j = 1 p a ( j ) s j ( C ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> W ( i , j ) ⩾ 0 , ∀ i ∈ { 1,2 ⋯ , N } , j = { 1,2 ⋯ , N } https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 0 ≤ s j 20 x iai ≤ 1 , ∀ i ∈ { 1,2 ⋯ , N } , j = { 1,2 ⋯ , p } https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 0 ≤ j j , x ial ≤ 1 , ∀ i ∈ { 1,2 ⋯ , N } , j = { 1,2 ⋯ , p } https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 0 ⩽ s } cther x ap ∣ x kk ≤ 1 , ∀ i ∈ { 1,2 ⋯ , N } , = { 1,2 ⋯ , p } , k = { 1,2 ⋯ , N } , A ( t , i ) = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , 62. ALGORITHM OF COOPERATION MODEL 62.1. Cooperative optimization model As mentioned above, there are many effective methods to obtain the weights of alternatives Including the subjective method like AHP, and the aggregation method such as TOPSIS, Entropy. We introduce the subjective method in this paper, and for further research the other methods should be reviewed and an improved method should be proposed according to the obtained information in the process of decision-making. Firstly, the experts will evaluate the weight of the department itself. And value of department A for option i under criteria j is defined as https://www.w3.org/1998/Math/MathML"> s ( A , i ; k ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , where https://www.w3.org/1998/Math/MathML"> 0 ≤ s ( A , i ; k ) ≤ 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , moreover, the bigger the value, the importance of the alternative is While applied to the cooperative decision-making model, the related departments (if https://www.w3.org/1998/Math/MathML"> A ( i , j ) = 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) should make comments on the reliability of each alternative. The method is similar with the method utilized by the department itself. But an important theme to notice is that the weight is related to different options, thus the department A chooses option A1 under the situation of the department B chooses option B2 under criteria can be defined as https://www.w3.org/1998/Math/MathML"> s ( B , B 2 , A , A 1 ; k ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 63. 4.2 Computation of combination option under each criterion The option of department i was defined as https://www.w3.org/1998/Math/MathML"> C ( i ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> when the combination option is C, thus the value of https://www.w3.org/1998/Math/MathML"> C ( i ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> under criteria k can be described as equation (4). https://www.w3.org/1998/Math/MathML"> s ( C ( i ) , C ; k ) = ∑ jA ( U , j ) - 1 W ( j , i ) s ( i , C ( i ) , j , C ( j ) ; k ) + W ( i , i ) s ( i , C ( i ) ; k ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The value of combination option is a vector of the value of each department. Suppose the number of departments is N, thus the value of the combination option under criteria k is shown in equation (5). https://www.w3.org/1998/Math/MathML"> s ( C ; k ) = s ( C ( 1 ) , C ; k ) , ⋯ , s ( C ( i ) , C ; k ) ⋯ s ( C ( N ) , C ; k ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 64. 4.3 Computation of combination option The value of combination option is defined as equation (6). https://www.w3.org/1998/Math/MathML"> s ( C ) = ∑ i = 1 8 a ( k ) s ( C ; k ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The value of combination option https://www.w3.org/1998/Math/MathML"> s ( C ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is a vector in practice. Thus the optimization option can be obtained by the comparison of different vectors under different options. 64.1. Best option selection In the process of cooperative decision making, the interest of each department should be taken into consideration in this cooperative decision-making model. Sometimes, one of department should take rigorous option while the combination is the best option. Thus a threshold value method should be predefined to exclude the rigorous option. Firstly, each option should have a minimum value. If the value of any option for any department is smaller than the predefined minimum value 0.3, the corresponding option should be excluded. Secondly, the best combination option is selected by normalized weighting method. Suppose the number of departments are N, thus each cooperative option is an N dimensional vector. If the vector elements are described as https://www.w3.org/1998/Math/MathML"> s ( 1 ) , s ( 2 ) , ⋯ , s ( N ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the combination value can be obtained. https://www.w3.org/1998/Math/MathML"> s ( C ) = ∑ k = 1 c b ( t ) s ( t ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where https://www.w3.org/1998/Math/MathML"> b ( i ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> means the importance or the weight of department i, and the weight can be obtained by the commander of the emergency cooperative decision making. 65. COOPERATIVE DECISION-MAKING FOR 66. 5.1 Scenario analysis A ship accident was used as a case study in Jiangyin port in Yangzi River. The ship was not under control because of its rudder failure. This case was supposed to be an emergency event, and the ship would collide with other ships if any efficient methods were not adopted. The navigational environmental factors and the ship condition were shown as follows. Ship condition: not under control for rudder failure, but the Jury Rudder was available. And main engines and anchors work well. Ship Tonnage: 10,000 DWT (Dead Weight Tonnage). Channel: vessel Traffic Separation Scheme (TSS) was established, this channel is suitable for one-way traffic of 50,000 DWT, and two-way traffic of 30 , 000 DWT. But the depths of surrounding waterway area were good and suitable for ship under 5,000 DWT. Anchorages: the nearest anchorage is about 3 nautical miles (NM). Navigational structures: there are few navigational structures, but no obstructive navigational structures exited in the nearby waterway such as bridges. Shoals: there are many wharfs nearby; only one shoal was available for beach landing. Traffic flow: one-way traffic flow was about 70 vessels per hour including https://www.w3.org/1998/Math/MathML"> 60 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of ship under 5000 DWT. In order to achieve a cooperative decision-making option, three experts (decision makers) were invited to give expert knowledge on this scenario. Each expert represents one department in this cooperative decision-making case, and the background of each expert is as follows. Chief mate: representative of the accidental ship (department A). He has been worked on an oceangoing ship as a chief mate for two years, and he has worked as a seaman more than ten years. Second mate: representative of the ship passing-by (department B). He has been worked on ocean-going ship as a second mate for three years, and he has worked as a seaman more than ten years. Staff in MSA: He has worked in Vessel Traffic System department for six years. And he is the reprehensive of MSA (department C ). 67. 5.2 Options and criteria The three experts were invited to make judgment on the options listed in Table 3 . Though some of the options are not suitable for this case study, all options were requested to be judged by each expert. This is required to make the whole model sensible and reasonable, but in practice especially in emergency event, the option that was unlikely to be taken up could be omitted according to the suggestions of experts. The criteria utilized for judgment in this case study were cost (CT), effectiveness (EF) and possibility (PB) respectively. The assumption should be made that only the own interest would be taken into consideration since each of them represent one department. In order to simplify the decision-making process, the weight of each criterion is predefined. https://www.w3.org/1998/Math/MathML"> W = W e , W e , W p = ( 0.2,0.4,0.4 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . and the judgment of each option under different criteria is shown in Table 2 where comprehensive result (CR) was also given. The table presents that the importance of each option under the abovementioned criteria. The bigger value means that the estimated cost of this option is smaller. While the bigger value effectiveness means the option is more effective. And the bigger value of possibility represent the option is more feasible. The judgments of these options are according to the following factors which ware proposed by experts. (1) Option A3 cost most because the ship would be damaged if the speed and heading of grounding is not well-controlled. Option Al is more effective because the traffic flow would not be influenced after anchoring, While Option A2 and https://www.w3.org/1998/Math/MathML"> A 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> could be easily adopted. (2) Option B1 owns the merits of less cost and more effectiveness because https://www.w3.org/1998/Math/MathML"> 60 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ship could bypass the channel. Option B2 seems to be more possible because the influence of accidental ship. (3) Option C1 would be most useful to end the chaos situation. Table 2. Judgment of each option under different criteria option CT EF PB CR option A1 0.7 0.7 0.5 0.62 option A2 0.5 0.6 0.8 0.66 option A3 0.4 0.6 0.8 0.64 option B1 0.7 0.8 0.6 0.7 option B2 0.3 0.8 0.7 0.66 option B3 0.2 0.5 0.5 0.44 option C1 0.5 0.6 0.7 0.62 option C2 0.4 0.5 0.4 0.44 option C3 0.5 0.4 0.4 0.42 68. 5.3 Cooperative group decision-making (CGDM) From the perspective of accidental ship, the best choice is anchoring in the channel. But this option would influence the ship passing-by even cause congestion. Thus the experts were requested to make judgment on the options of other departments. And the results were shown in Table 3 . Table 3 reveals that the result of option https://www.w3.org/1998/Math/MathML"> B 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and C3 was significantly lower than the other options. This is because if the ship passing-by stops sailing, the whole waterway would be congested. Moreover, the ship passing-by would also get loss during the stopover which could conclude from the judgment on B3 under different options of department A. similarly, the judgment on option C3 is also lower than others because closure of navigation will make the other ships congested. Table 3. Judgment on options (OP) of other departments Table 3. Judgment on options (OP) of other departments OP https://www.w3.org/1998/Math/MathML"> A 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> A 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> A 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> B 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> B 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> B 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> C 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> C 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> C 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> B 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.8 0.7 0.8 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.7 0.3 0.15 https://www.w3.org/1998/Math/MathML"> B 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.6 0.6 0.4 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.2 0.3 0.15 https://www.w3.org/1998/Math/MathML"> B 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.3 0.3 0.3 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.2 0.3 0.1 https://www.w3.org/1998/Math/MathML"> C 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.8 0.8 0.4 0.6 0.5 0.15 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> C 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.5 0.6 0.4 0.4 0.6 0.15 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> C 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.2 0.2 0.2 0.2 0.3 0.25 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The cooperative The cooperative decision-making was then applied to model. In this study, the cooperative coefficient W is predefined as 0.5, otherwise if no cooperative is conducted, cooperative coefficient is 1.0. The result of computation was shown in Table 5. It should be mentioned that only the combination option (CO) and its three components https://www.w3.org/1998/Math/MathML"> ( F C , S C , T C ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> under https://www.w3.org/1998/Math/MathML"> A 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was listed in Table 4. Table 4. Result of computation CO FC SC TC A1B1C1 0.71 0.65 0.66 A1B1C2 0.635 0.55 0.37 A1B1C3 0.56 0.45 0.285 A1B2C1 0.66 0.58 0.41 A1B2C2 0.585 0.63 0.37 A1B2C3 0.51 0.48 0.285 A1B3C1 0.585 0.295 0.41 A1B3C2 0.51 0.295 0.37 A1B3C3 0.435 0.345 0.26 It could easily obtained from Table 4 that some values was lower than 0.3. According to the algorithm proposed in section 4.4, these options should be excluded because they were not supposed to be recognized by other cooperative departments, and the value lower than a minimum value were in bold in Table 4. Thus 12 combination options were recognized by all departments which were shown in Table 5. Table 5. Effective combination options CO FC SC TC https://www.w3.org/1998/Math/MathML"> A 1 B 1 C 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.71 0.65 0.66 https://www.w3.org/1998/Math/MathML"> A 1 B 1 C 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.635 0.55 0.37 https://www.w3.org/1998/Math/MathML"> A 1 B 2 C 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.66 0.58 0.41 https://www.w3.org/1998/Math/MathML"> A 1 B 2 C 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.585 0.63 0.37 https://www.w3.org/1998/Math/MathML"> A 2 B 1 C 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.705 0.65 0.66 https://www.w3.org/1998/Math/MathML"> A 2 B 1 C 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.655 0.55 0.37 https://www.w3.org/1998/Math/MathML"> A 2 B 2 C 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.68 0.58 0.41 https://www.w3.org/1998/Math/MathML"> A 2 B 2 C 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.63 0.63 0.37 https://www.w3.org/1998/Math/MathML"> A 3 B 1 C 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.62 0.65 0.66 https://www.w3.org/1998/Math/MathML"> A 3 B 1 C 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.62 0.55 0.37 https://www.w3.org/1998/Math/MathML"> A 3 B 2 C 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.52 0.58 0.41 https://www.w3.org/1998/Math/MathML"> A 3 B 2 C 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.52 0.63 0.37 68.1. Cooperative group decision-making (CGDM) The weight of each department was then utilized to computation of combination options. Since the accidental ship plays an essential role in triggering the actions of other departments, the weights of the three departments were supposed as https://www.w3.org/1998/Math/MathML"> W A , W B , W C = ( 0.5,0.25,0.25 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The comparison between cooperative and uncooperative method was shown in Table 6 . As shown in Table 6, the result of the two methods varies from each other. The best choice of cooperative method is https://www.w3.org/1998/Math/MathML"> A 1 B 1 C 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , while the uncooperative method is https://www.w3.org/1998/Math/MathML"> A 2 B 1 C 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The choice of https://www.w3.org/1998/Math/MathML"> A 2 B 1 C 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> makes sense only if each department considers the interests of itself. But this choice ignores the interests of other departments, and the cooperative method could make a comprehensive choice. From the perspective of experts, the accidental ship could use Jury Rudder to control heading since the anchorage was not far away and the traffic flow was not density. Correspondingly, majority of ship passing-by could bypass the channel because the depths of surrounding waterway were suitable for majority of the ships. And MSA could make traffic organization to ensure the safety of the accidental ship. Table 6. Comparison between cooperative and uncooperative method option CGDM ranking MCDM ranking A1B1C1 0.6825 1 0.63 5 A1B1C2 0.5475 8 0.585 11 A1B2C1 0.5775 5 0.62 6 A1B2C2 0.5425 9 0.575 12 A2B1C1 0.68 2 0.66 1 A2B1C2 0.5575 7 0.615 7 A2B2C1 0.5875 4 0.65 2 A2B2C2 0.565 6 0.605 8 A3B1C1 0.6375 3 0.65 2 A3B1C2 0.54 10 0.605 8 A3B2C1 0.5075 12 0.64 4 A3B2C2 0.51 11 0.595 10 69. CONCLUSIONS AND REMARKS Compared with the traditional MCDM, the CGDM model could take the suggestions of other departments into consideration. Thus the combination option of this method seems to be more feasible and effective. And this methodology could be widely applied to emergency response of ship accident. In this study, the weights of different departments were predefined. An improved method should be proposed especially when the accidental ship is in traditional incident. And future work on this field should be conducted. As mentioned in Section 5, the ship could anchor in the anchorage because few interference of ship passed. Actually the option would change according to the different navigational environment and ship condition. For example, if the ship is not under control owning to the machinery failure as well as rudder failure, the best option would be changed. Moreover, if the accidental ship should pass a bridge in this scenario, the option of anchoring in anchorage should be omitted for its high level risk. Thus a feasible decision-making model for accidental ship should be incorporated into this cooperative model in the future research. 70. ACKNOWLEDGEMENT This Paper is supported by Research Fund for the Doctoral Program of Higher Education of China (Grant No.20130143120014). 71. REFERENCES Altuzarra, A., Moreno-Jiménez, J.M. & Salvador, M. (2007). A Bayesian priorization procedure for AHP-group decision making. European Journal of Operation Research 182(1):367-382. Amgoud, L. & Prade, H. (2009). Using arguments for making and explaining decisions. Artificial Intelligence173(34): 413-436. Cook, W.D. (2006). Distance-based and ad hoc consensus models in ordinal preference ranking. European Journal of Operation Research 172(2): 369-385 . Chen, X., Wang, Y., Wu, L.Y., Yan, G.Y. & Zhu, W. (2010). Emergency decision model multiple stages, multiple objectives, and multidivisional cooperation. System Engineering-Theory and Practice 30(11): 1977-1985. Chen, Y.L. & Cheng, L.C. (2009). Mining maximum consensus sequences from group ranking data. European Journal of Operation Research 198(1): 241-251. Dong, Y.C., Xua, Y.F. & Yu, S. (2009). Linguistic multi person decision making based on the use of multiple preference relations. Fuzzy Sets and Systems 160(5):603623 . Fan, Z.P., Ma, J., Jiang, Y.P., Sun, Y.H. & Ma, L. (2006). A goal programming approach to group decision making based on multiplicative preference relations and fuzzy preference relations. European Journal of Operation Research 174(1):311-321 Huang, Y.S., Chang, W.C., Li, W. H. & Lin, Z.L. (2013). Aggregation of utility-based individual preferences for group decision-making. European Journal of Operation Research 209(2) :462-469. Liu, F., Zhang, W.G. & Wang, Z.X. (2012). A goal programming model for incomplete interval multiplicative preference relations and its application in group decisionmaking. European Journal of Operation Research https://www.w3.org/1998/Math/MathML"> 218 ( 3 ) ; 747 - 754 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Mateos, A., Jiménez, A. & Ríos-Insua, S. (2006). Monte Carlo simulation techniques for group decision making with incomplete information. European Journal of Operation Research 174(3):1842-1864. Ōlçer, A.I. & Ōdabaşi, A.Y. (2005). A new fuzzy multiple attributive group decision making methodology and its application to propulsion/maneuvering system selection problem. European Journal of Operation Research 166(1):93-114. Xia, M.M. & Xu, Z.S.(2012).Entropy/cross entropy-based group decision making under intuitionistic fuzzy environment. Information Fusion 13(1):31-47. Xie, K.F., Chen, G., Wu, Q., Liu, Y. & Wang, P. (2011) Research on the group decision-making about emergency event based on network technology. Information Technology and Management 12(2): 137-147. Xu, D. L., Yang, J.B. & Wang, Y.M. (2006). The evidential reasoning approach for multi-attribute decision analysis under interval uncertainty. European Journal of Operation Research 174(3):1914-1943. https://www.w3.org/1998/Math/MathML"> X u , Z . S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . (2007). A method for multiple attribute decision making with incomplete weight information in linguistic setting. Knowledge based Systems 20(8): 719-725. Xu, Z.S. (2013). Group decision making model and approach based on interval preference orderings. Computers & Industrial Engineering 64(3): 797-803. Yeh, C.H. & Chang, Y.H. (2009).Modeling subjective evaluation for fuzzy group multi criteria decision making. European Journal of Operation Research 194(2): 464-473. Yu, L., Wang S.Y & Lai, K.K. (2009). An intelligent-agentbased fuzzy group decision making model for financial multi criteria decision support: The case of credit scoring. European Journal of Operation Research 195(3):942-959. The Concept of Emergency Notification System for Inland Navigation T. Perzyński, A. Lewiński & Z. Eukasik University of Technology and Humanities in Radom, Poland Abstract The paper presents solutions used in Polish inland navigation which raise safety in a water area, especially in water tourism. Solutions presented in the article allow limiting the dangerous events caused by weather phenomenon. As a result of the use of described solutions, a number of injured people can be decreased. In the article the conception of new system which allows faster reaction of emergency services (e.g. Aquatic Volunteer Emergency Corps) in dangerous situations is presented. The conception of the system proposed in the paper can be very useful particularly in faster localization of capsized sailing yacht. The conception is based on telematic solutions (GPS, GSM). Introduced mathematical model of presented system related to theory of stochastic processes allows estimating the quantitative reliability and time criteria of safety. 72. INTRODUCTION In recent years, we will notice a big change in water tourism in Poland. Investments in ports, marinas and all the water infrastructure is essential to attract tourists. The popularity of this type of tourism is not only a greater availability of water equipment and boat, but also a change in existing legislation, both for sailboats and motorboats https://www.w3.org/1998/Math/MathML"> [ 1 ] , [ 2 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The current regulation regarding to water tourism allows sailing up to https://www.w3.org/1998/Math/MathML"> 7.5 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> yacht length of the hull without documented skills (certificate of competency). In case of motor boats, the navigation is permitted without certificate of competency with an engine power up to https://www.w3.org/1998/Math/MathML"> 10 k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In the last amendment of the act about inland waterway there has been added one more law regulation (art. 37 a https://www.w3.org/1998/Math/MathML"> 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) with reference to the motorboat, which exempts the users of yachts with engine power up to https://www.w3.org/1998/Math/MathML"> 75   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with a hull length up to https://www.w3.org/1998/Math/MathML"> 13   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , where the maximum speed is structurally limited to https://www.w3.org/1998/Math/MathML"> 15   k m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Fig. 1.) from the requirement of the qualifying certificate, therefore the big popularity of cabin cruiser. The changes in the construction of boats and their equipment as well as noticeable changes in the infrastructure still do not ensure a sufficient level of safety. Hence, the concept of the proposed system for tourist yachts, of which idea was born during sailing student camps. Changing weather conditions, even in the summer, violent gusts of wind, cause the need for quick reaction in the event of a dangerous situation. More comfortable yachts cause the need to build boats with high board. The air mass in spite of folded sails may capsize boat. Currently there are no such solutions on the Polish lakes. Thus the authors proposed to build a system for enhanced safety which enables quick finding of people who need help. The proposed system is similar to those used in open waters - EPIRB (Emergency Position Indicating Radio Beacon). Thanks to the different form of sending a message (action based on the GSM network) it will not require registration at the Office of Civil Aviation [6]. 73. CURRENT SOLUTIONS The first system improving safety at Masurian Lakes is warning system before weather phenomena which has been activated in 2011 . The people on lakes are informed about weather danger by light signals placed on the appropriate masts (Fig. 1). Without specifying the time and place of arrival of meteorological phenomena, sailors are informed by flash signal occurring at a frequency of 40 flashes per minute. It means that storm or high winds are expected. Imminent danger of storms and strong winds is indicated by 90 flashes per minute. In this case it is better to stay in harbour or quickly sail there. The principle operation of this system is presented on the Fig. 1. Figure 1. Simplified scheme of principle operation warning system before weather phenomena [7]. Information concerning the weather for Mazurian Lakes is transferred from the Institute of Meteorology and Water Management - National Research to Regional Water management Authority in Warsaw, where it is analysed. After receiving the information about the weather conditions, appropriate software interprets the message and if it is significant, it sends a signal to the masts and turns them on automatically. The light signals stop transmitting the light message after cancelling or expiration of the announcement. Currently the system consists of 17 masts and the led light which is visible from https://www.w3.org/1998/Math/MathML"> 8 - 9   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> distance. 1. THE CONCEPT OF THE SYSTEM The most common reason of capsizing the boat is unexpected and violent wind. The first step after capsizing is to check the status of the crew. The crew is often shocked. Next step is attempt to seek help, but very often sunken mobile phones disable emergency call. The pictures of capsized yacht are presented in the Fig. 2 (Mazurian Lakes - August 2007). The concept of the proposed system (Emergency Notification System - ENoS) assumes full autonomous operation. In the situation like on the pictures above, the device automatically sends message (SOS) to the rescue service providing position. The device which sends the signal will be in a hermetic case with own power supply system. The algorithm of the system is shown on the Fig. 3 . Figure 2. Boat capsizing [6]. Figure 4. The principle of operation of the system [own source] The proposed concept assumes that the accelerometer will be used as a tilt sensor. After crossing https://www.w3.org/1998/Math/MathML"> 90 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tilt angle, system turns on and sends a message. In the case of absence of a current GPS signal from a satellite, system takes last saved position from the buffer (for example https://www.w3.org/1998/Math/MathML"> 5   m i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> before). The proposed system can also be equipped with additional functions such as belt tilt (inclinometers). In the event of bringing the boat to its initial position the center of buoyancy is changing and righting moment arises. The largest righting moment is at an angle of approximately https://www.w3.org/1998/Math/MathML"> 40 ∘ [ 4 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In this case system can signal the dangerous situation to the skipper. The principle of operation of the system is shown on Fig. 4 . 2. MARKOV MODEL OF ENOS SYSTEM Processes related to accidents on the waters can be assimilated to the group of stochastic processes, where a group of random variables is defined in the probability space. In order to make an analysis the proposed system suggested mathematical apparatus (the theory of stochastic processes) in the form of Markov model. Stochastic process https://www.w3.org/1998/Math/MathML"> X ( t ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is called the Markov process, if for any finite system https://www.w3.org/1998/Math/MathML"> t 1 < t 2 < … < t n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> parameter value and for any real numbers https://www.w3.org/1998/Math/MathML"> x 1 , x 2 , … . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> x n : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> P X t n < x n ∣ X t n - 1 = x n - 1 , X t n - 2 = x n - 2 , … , X t 1 = x 1 = = P X t n < x n ∣ X t n - 1 = x n - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Conditional distribution https://www.w3.org/1998/Math/MathML"> X t n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at a given values https://www.w3.org/1998/Math/MathML"> X t 1 , … , X t n - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> depends only on https://www.w3.org/1998/Math/MathML"> X t n - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Markov processes are described by the distribution of two dimensional (time and states of the process). The theory of stochastic processes is used for two reasons:

safety analysis (probability of a critical event, the unavailability of the proposed system) of equipment based on typical probabilistic and exploitation characteristics,

safety assessment of boat taking into consideration the standard procedures used in the occurrence of the event (including time parameters) with regard to the functioning of the proposed system under different environmental conditions and climate.

2.1. Markov model for GPS/GSM in ENoS system Assuming exponential distribution of faults, stationary, homogenous and ergodic character of stochastic Markov process, the model of GPS/GSM in ENoS was built (Fig. 5). Figure 5. Markov model of GPS/GSM in ENoS system [own source] where: https://www.w3.org/1998/Math/MathML"> λ - λ 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - failure rate, https://www.w3.org/1998/Math/MathML"> μ - μ 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - intensity of service, In the model from Fig. 5 we can distinguish the following states. 0 - state of safety. In the event of danger situation system is correctly working and sending the messages. 1 - no GSM signal. 2 - no GPS signal. 3 - no GPS and GSM signal. For the proposed model can write equation: https://www.w3.org/1998/Math/MathML"> dP 0 dt = - λ 1 ⋅ P 0 + μ 1 ⋅ P 1 - λ 2 ⋅ P 0 + μ 2 ⋅ P 2 + μ ⋅ P 3 dP 1 dt = λ 1 ⋅ P 0 - μ 1 ⋅ P 1 - λ ⋅ P 1 dP 2 dt = λ 2 ⋅ P 0 - μ 2 ⋅ P 1 - λ ⋅ P 2 dP 3 dt = λ ⋅ P 1 + λ ⋅ P 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429225857/9d43ee8b-242c-4aed-a743-c483516ce2bb/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> In order to solve the system of computer-aided equations was used - Mathematica software. The window is presented on Fig. 6. The most dangerous state in the model The most dangerous state in the model is state number 3 and state 1 corresponds to GSM communication. Assuming the parameters of coefficients presented in the Fig. 5 , as below: