Researchs On Strong Interference Suppression Technique For Linear Array Sonar

With the development of damping and noise reduction technology,the radiated noise of submarine targets has been significantly reduced.In the marine environment,it is often the influence of near and far interference,which causes the radiated noise signal of attention to be overwhelmed by interference.Therefore,the effective suppression of strong spatial interference is of great significance for the detection of weak targets.In this paper,the strong interference suppression method of linear array is studied based on the field beam formation,near-field acoustic focusing and adaptive noise cancellation.The research contents of this thesis mainly include:1?The far-field interference suppression technology based on beamforming.The interference suppression method based on the minimum distortion response(MVDR)and the interference suppression method based on the null constraint of the beam pattern are studied,which involves null broadening,performance comparison and characteristic analysis of the beam signal.Finally,the above method is applied to the data processing of sea test experiment,and the results show that both methods can effectively suppress the interference of far-field strength and enhance the display effect of the target signal.2?The sonar platform near-field interference suppression technology.The principle of near-field acoustic focusing is introduced,the concept and realization method of noise shielding are extended,and the method of shielding area broadening is studied.The simulation results of acoustic shielding technology show that the near-field interference is stronger than the target signal,and the technique can restrain the near-field interference effectively and obtain the target location information.A near-field multipath interference suppression technique based on acoustic shielding is proposed,and the simulation results show that this method can effectively suppress near-field multipath strong interference.Finally,the post-beam interference cancellation(PIC)technology based on adaptive noise cancellation is studied,and the suppression of near-field jamming signal under ideal conditions is realized by simulation,and the feasibility of this method is verified.