Waveguide Invariant Reverberation Mitigation for Active Sonar

Reverberation often limits the performance of active sonar systems. A method of target detection and bottom-feature suppression has been developed exploiting waveguide-invariant phenomena and the frequency-selective fading properties of broadband reverberation in shallow water channels. Specifically, the mean reverberation power is estimated along the striations in the reverberation spectrogram predicted by waveguide invariant theory, where the expected power is constant. Preliminary simulations indicate that significant performance increases are possible over traditional cell-averaging constant false alarm rate (CA-CFAR) methods in the detection of weak targets in reverberation and differentiating between bottom features and water column targets.