An experimental comparison of optimum and sub-optimum filters' effectiveness in the generalized correlator

Abstract Various optimum and sub-optimum filters have been added to the basic cross-correlator in order to enhance its detection and estimation capabilities in the presence of noise. These pre-detection filters include the Hannan-Thomson, the Eckart, the Smoothed Coherence Transform, some least-squares, and two optimum filters recently derived by the authors. Here, a quantitative comparison of all six filters has been conducted by extensive simulation for various input signal to noise ratios and signal and noise bandwidths. The results define the actual enhancement in time delay detection and estimation when using the optimum filters and the amount of performance degradation from the optimum for the other filters. The rank ordering of the filters is carried out. Histograms of the time delay estimates, their mean, variance and probability of detection are presented. Wherever available, comparison of analytical predictions with the experimental results is noted.