A direct wave interference suppression algorithm for bistatic sonar
Aiming at the problem that the target detection performance of the bistatic sonar degrades under strong direct wave interference,a direct wave suppression method based on filtering in the fractional Fourier transform(FRFT)domain is proposed.In this method,the transmitted signal is weighted by the Nuttall window,and the direct wave interference is suppressed by fractional domain zero filtering at the receiving end.Then,the target delay information is extracted by frequency domain adaptive matched filtering(FDAMF)to realize the target detection under direct wave interference.The simulation results show that the algorithm can effectively suppress the direct wave interference,accurately estimate the target delay position and successfully detect the target when the power ratio of the target echo to the direct wave interference is-23 dB.Under the condition of target motion,the algorithm estimates the Doppler frequency offset by searching for the optimal order in the fractional domain,and performs FDAMF detection after frequency offset compensation,which can significantly improve the detection performance of the frequency domain adaptive matched filter.
direct wave interferencefractional Fourier transform(FRFT)Nuttall windowfrequency domain adaptive matched filter(FDAMF)
万方数据
维普
