Continuous active sonar reverberation suppression for real-time processing

To mitigate the masking of weak target echoes by cumulative reverberation in continuous active sonar (CAS), and to achieve real-time reverberation suppression under the constraints of short detection windows, this paper proposes a sequential subband sparse filtering with QR decomposition (QR) updates method based on low-rank and sparse decomposition. By leveraging the inherent sequential nature of CAS subband outputs, a low-rank background model is constructed via incremental QR updates. This framework allows for the rapid extraction of sparse components from each subband, effectively separating steady-state reverberation, reverberation fluctuations, and target echoes. Validation using shallow-water experimental data demonstrates that the proposed method achieves rapid convergence with only a few subband inputs. It significantly reduces interference from reverberation fluctuations, maintains the structural continuity of targets under low signal-to-noise ratio conditions, and improves the detectability of weak echoes. The online separation framework ensures superior computational efficiency while enhancing system adaptability to complex reverberant environments.