Reverberation Suppression Using Wideband Doppler-Sensitive Pulses

The influence of transmitted waveforms on the signal-to-reverberation ratio (SRR) of a low-frequency active sonar is analyzed both theoretically and experimentally. Reverberation experiments have been conducted during a sea trial in a littoral water environment in October 1999. The aim of the trials was to compare the performance of three classes of waveforms: standard hyperbolic frequency-modulated (HFM) waveforms, continuous waveforms (CWs), and innovative pulse trains of linear frequency-modulated (PTFM) waveforms. Transmissions were combined (CW/PTFM train) or intermitted (HFM) to compare the performance of the three classes in (exactly) the same environment. Experimental results in highly reverberant environment illustrated that PTFM pulses allow a reduction in reverberation power greater than 10 dB over the standard detection pulses for slowly moving targets. The results are in agreement with theoretical predictions.