ABSTRACT
This chapter introduces band-limited decimation which is performed directly on an original long signal leading to a short signal to which any desired method could be applied for subsequent data processing. To initialize windowing in the time domain, the long signal is first subjected to the fast Fourier Transform (FFT). This yields a low resolution spectrum, since the length of the signal is generally insufficient for the FFT to resolve dense nodal frequencies. The chapter re-emphasizes that the whole procedure of the band-limited decimation leads to no loss of information in any of selected windows. This technique gives theoretically equivalent bid-signals of the same short lengths. The chapter presents the main working prescription for the application of the band-limited decimation. The final result of this preprocessing via successive applications of the direct and inverse FFT is a substantially shorter band-limited decimated signal which can afterwards be subjected to any selected estimator for the parametric or non-parametric spectral analysis.
