一种基于MVDR-MMP的水面干扰抑制方法

A method to suppress surface interference based on MVDR-MMP

在水面离散强干扰下检测和定位水下安静目标是浅海匹配处理中的一个重要问题.根据简正波理论,声场是所有传播模态的叠加,而这些模态是深度的函数.理论上,浅海常见的负梯度声速剖面下,水面声源和水下声源激发的简正波模态具有明显差异性.基于模匹配处理方法,通过对声源激发简正波模态的筛选,对水面干扰进行抑制.仿真表明:匹配模处理能够有效进行干扰和目标的定位,而常规低阶匹配模处理能够在较低精度下抑制水面干扰,而对角加载的MVDR匹配模处理能够在此基础上有效抑制旁瓣,提高定位精度.

Detecting and localizing submerged target in the presence of loud interfering surface ships is an important problem for matched field processing in shallow water.According to normal mode theory,the complete acoustic field is constructed by summing up contributions of each of the modes weighted in accordance to the source depths.It has been proved that the mode orders motivated by surface and submerged sources are very different with negative sound velocity profile.The purpose of this work is to suppress the surface interference by selecting modes based on matched mode processing(MMP).The simulation illustrates that MMP can localize the submerged target and surface interference,and surface interference can be suppressed using conventional MMP(CMMP)by some low order modes with low precision.Furthermore,diagonal loading minimum variance distortionless response(DL-MVDR)MMP can suppress the sidelobe,and improve the localization precision compared to CMMP.