Empirical mode decomposition applied for tow-ship noise signal reconstruction and cancelling

According to the characteristic of the tow-ship in temporal and spatial domain,it proposed an interference cancelling method which combined EMD with inverse Beamforming algorithm.For solve the shortcoming that it needs manual intervention to choose the Multi-IMF components which generated by EMD,it proposed a choosing algorithm,in which the chosen IMF component decided by the maximum power spectrum coefficient rule.In the choosing algorithm, the line power spectrum coefficient matrix obtained by the spectrum correlation function between the two line spectrums of Multi-IMF components and array domain signal,and the continue power spectrum matrix could be obtained in the same way.Based on the theory of inverse beamforming,it derived the process of spectrum subtraction between the original and the reconstructed array domain data which obtained by the chosen IMF component.The process of bearing estimation is based on the spectrum subtracted array domain data.The results of the towed sonar simulator and real sea trial data showed that the proposed method could enhance the weak target's spatial gain,especially the spatial gain could be improved significantly when the weak target located in the interference area.It also showed that the proposed method has the capability of cancelling the multipath angle scatter interference.