一种双基声呐直达波干扰抑制算法  

A direct wave interference suppression algorithm for bistatic sonar

作　　者：梁琴 胡鹏鹏 陈洲 李捷[1] 王婷婷 LIANG Qin;HU Pengpeng;CHEN Zhou;LI Jie;WANG Tingting(Sichuan Jiuzhou Electric Group Co.,Ltd.,Chengdu 610095,Sichuan,China)

机构地区：[1]四川九洲电器集团有限责任公司,四川成都610095

出　　处：《声学技术》2024年第4期585-592,共8页Technical Acoustics

基　　金：装备预研基金项目(6140415031)。

摘　　要：针对双基声呐中强直达波干扰下目标检测性能下降的问题,提出了基于分数阶傅里叶变换域滤波的直达波抑制方法。该方法首先对发射信号进行纳托尔(Nuttall)窗加权,在接收端采用分数阶域置零滤波抑制直达波干扰,再通过频域自适应匹配滤波提取目标时延信息,从而实现直达波干扰下的目标检测。仿真结果表明,在目标回波与直达波干扰功率比为-23 dB的情况下,该算法可有效抑制直达波干扰,准确估计出目标时延,成功检测到目标。在目标运动时,该算法通过在分数阶域搜索最佳阶数估计出多普勒频偏,并对其做频偏补偿后的频域自适应匹配滤波检测,可显著提高频域自适应匹配滤波器的检测性能。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.

关 键 词：直达波干扰 分数阶傅里叶变换 纳托尔(Nuttall)窗 频域自适应匹配滤波器 

分 类 号：TB56[交通运输工程—水声工程]