Research on adaptive matched filtering algorithm of active sonar echo signal

Matched filter is the best detector of active sonar in the background of Gaussian white noise, but its detection performance is limited, and often can not meet the detection requirements under the condition of lower signal-to-noise ratio (SNR). In order to detect the echo signal under the condition of lower signal-to-noise ratio, an adaptive matched filter algorithm based on conventional matched filter, t0 filter, correlation denoising and adaptive line spectrum enhancement processing is proposed in this paper. The matched filter output signal is first processed by t0 filtering, then by correlation denoising and adaptive line spectrum enhancement. After triple processing, the echo signal and interference can be separated under the background of low SNR, which significantly improves the output SNR. The simulation results show that the algorithm proposed in this paper can significantly improve the echo detection ability under the condition of weak SNR, and can detect the -20db echo signal after beamforming, and the performance is significantly better than the traditional matched filter.