Active Sonar transmission strategies in the presence of strong direct blast

With the help of in-water experimentation data, we study: (1) the merits and limitations of two major classes of Active Sonar Systems, namely, Pulse Active Sonar (PAS) and Continuous Active Sonar (CAS), with the Doppler-Tolerant Linear Frequency Modulation (LFM) waveform; and (2) the merits and limitations of Doppler-Tolerant LFM and the Doppler-Sensitive SHAPE waveforms with CAS. Throughout the study, Matched Filter (MF) is used as the receiver design. The strong delay and Doppler spread direct blast and poor MF performance in noisy environments warrant us to introduce processing techniques which enable receivers to produce accurate range estimates.