| The vector hydrophone has the advantages of comprehensive acquisition of sound field information and suppression of background noise.The sound vector array is widely used in shipboard broadside array sonar and towed array sonar.However,the shipborne sonar will be affected by the self-noise of the platform when it works.Compared with the far-field target signal,the energy is stronger,which seriously affects the sonar target detection performance.The shipborne sonar platform self-noise can be divided into two categories according to its characteristics: correlated noise and uncorrelated noise.Correlated noise mainly includes mechanical vibration noise,propeller noise,etc.,and uncorrelated noise mainly includes flow noise.In this paper,the research on the self-noise suppression of the shipborne sonar platform is of great significance to the research on the robust beamforming method of the shipborne sonar.In this paper,a simplified platform interference model is established according to the spatial distribution characteristics of shipborne sonar platform noise,and an array signal processing model is further established in combination with far-field targets.Theoretical research on spatial matrix filter is carried out,and simulation analysis is carried out on the commonly used optimization design criteria.A spatial matrix filter with interference suppression is selected and designed.The simulation results show that the azimuth estimation of the far-field target signal can be achieved while suppressing the background interference of the platform.Aiming at the fact that the moving platform is disturbed by flow noise,the idea of data covariance matrix diagonal load shedding is proposed.The MVDR target azimuth estimation with different diagonal load shedding methods is simulated and analyzed.The results show that when the received noise energy of each element channel of the vector array is inconsistent,the Uniform diagonal load shedding can effectively eliminate most of the noncorrelated noise components such as residual noise and flow noise after filtering,and the robust performance of the MVDR algorithm can be guaranteed by changing the threshold coefficient.Finally,the research on the vector array wideband signal target azimuth estimation method is carried out,and the performance of ISM and CSM two wideband signal target azimuth estimation algorithms is compared and analyzed.At the same time,the vector array broadband space-domain matrix filter is designed by sub-band division,which realizes the target bearing estimation of the far-field broadband signal under the noise interference of the vector flank array platform. |
