ABSTRACT
The signal detection theory for MSRSs may be considered as a part of the general spatial-temporal signal processing theory. However, most practical results of that general theory relate to processing of plane or spherical waves incident upon receiving antennas of given form and size, mainly upon phased antenna arrays (PAAs) [35,42,52,72]. As can be seen from Section 1.1, MSRSs have a number of peculiar features which are to be taken into account when developing the signal detection and parameter estimation theories. The main features are as follows:
The number and arrangement of stations may be arbitrary. Therefore the detection theory should be developed without connection with a specific system configuration.
The differences of signal propagation time from each target to spatially separated stations (TDOAs) are, as a rule, much greater than the reciprocals of signal bandwidths. In particular, this does not permit to separate the spatial processing of the sum of echoes and external interferences from the temporal processing (which is usually possible for antenna arrays).
A target may be positioned at any range from a MSRS, i.e. not necessarily in the far zone and even in the Freshnel’s zone with respect to the whole antenna system of the MSRS but, as a rule, in the far zone of each station’s antenna.
Mutual correlation of scattered signal fluctuations at the inputs of different stations may widely vary – from complete correlation (as at different elements of usual antenna arrays) to zero correlation (when the stations are separated by sufficiently large baselines).
There are some peculiar features depending on the type of a MSRS i.e. on the degree of spatial coherence, on the information integration level, cooperative or autonomous signal reception etc. (see Section 1.1).
