Research on noise reduction method for ship radiate noise based on secondary decomposition

Underwater acoustic signal denoising is of great significance for the accurate identification of underwater targets, the research of military detection equipment and the monitoring of marine ecological environment. In this paper, a new denoising method for ship radiated noise based on combined secondary optimization decomposition model, amplitude-aware permutation entropy, dynamic interval threshold filtering and mutual information is proposed. Compared with one-time decomposition, the proposed method can better restore the waveform characteristics of the original signal and filter out the mixed residual noise. In addition, this paper discoveries the influence of differential operation on phase diagram morphology under high signal-to-noise ratio. The experimental results show that the differential phase diagram can show the weak noise contained in the signal with high signal-to-noise ratio. This new discovery has been applied to the evaluation of noise reduction effect of underwater acoustic signal for the first time.