A method of noise and reverberation limiting sonar monitors

The author describes a novel method for limiting noise and reverberation on sonar screens that consists of deriving the return correlations of echo signals in successive transmissions and for successive ranges. As strict correlation computation is time consuming, five criteria that check the space coherence of the signals were proposed instead. The simulations performed have proved the practical usefulness of the method. It was found that for a large detection probability the false alarm probability could be decreased by a factor of about 100, as compared with the classical Neyman-Pearson method. The investigations were carried out for various signal-to-noise ratios (from 6 to -3 dB) and various values of detection probability. The method proved to be useful for signal-to-noise ratios larger than 0 dB and detection probabilities larger than 0.5