Physics-Based Improvements for Continuous Active Sonar (CAS)

SSC proposes to develop a novel motion-adaptive matched filter, tuning standard replicas to account for time-varying delays observed in received echoes. The method uses segments of the transmitted waveform to create a bank of time-dilated (Dopplerized) replicas to measure the time-varying delay of strong returns, accounting for unknown or unmeasured motions of the surface ship hull sonar, towed array, and target and thereby reducing signal mismatch. A physics model then dilates the original waveform accordingly, ultimately sharpening and increasing the SNR of target echoes.