Multi-Hydrophone Correlation Method for Passive Sonar Broadband Target Detection

To effectively solve the problem of passive sonar detection of broadband targets in low signal-to-noise ratio, the traditional dual-hydrophone correlation method for sound source localization is expanded into a multi-hydrophone correlation method, and the coherent accumulation of the output signals realizes the improvement of the signal-to-noise ratio at the receiving end. First, broadband filtering is used to calculate the channel demodulation signal of each hydrophone about the assumed sound source location. Second, the time-domain correlation of the accumulated signals of the two sets of hydrophones is calculated, and finally the time-domain correlation is thresholded. Simulation results show that, compared with dual hydrophones, the multi-hydrophone correlation method can achieve broadband target detection at a lower signal-to-noise ratio. In addition, considering that the calculation of filter coefficients requires a lot of calculations, an acceleration scheme using the principle of reciprocity is proposed. The simulation results show that the principle of reciprocity can effectively reduce the calculation of filter coefficients.