Research on Frequency Estimation Method of Underwater Target Echo Signal for Acoustic Decoy

The body target effect of the torpedo can affect the Doppler frequency estimation accuracy of the torpedo echo signal received by the detonating acoustic decoy fuze, which will cause errors in the position of the detonation point. A joint frequency estimation method of amplitude ratio and segmented phase difference (Rife-Segmented Phase Difference Method, referred to as RP method) is proposed. This method combines the traditional Rife algorithm and the segmented phase difference algorithm. By preprocessing the estimated signal frequency and adopting different estimation algorithms in different frequency bands, and high-precision estimation of Doppler frequency of the target echo signal is achieved. The simulation results show that the method has high estimation accuracy and good stability. It improves the accuracy of extracting the Doppler frequency information of the torpedo target echo, so as to realize the accurate prediction of the tipping point position and improve the probability and effect of torpedo damage. This method can be used for reference by relevant technicians.