多子阵合成孔径声呐后向投影自聚焦成像方法  

A back projection autofocus imaging method for multi-receiver synthetic aperture sonar

作　　者：姚永红 张旭[2] 宋伟 YAO Yong-hong;ZHANG Xu;SONG Wei(Department of Control Technology,Wuxi Institute of Technology,Wuxi 214121,China;Shanghai Acoustics Laboratory,Chinese Academy of Sciences,Shanghai 201815,China)

机构地区：[1]无锡职业技术学院控制技术学院,江苏无锡214121 [2]中国科学院声学研究所东海研究站,上海201815

出　　处：《舰船科学技术》2023年第20期176-181,共6页Ship Science and Technology

摘　　要：针对多子阵合成孔径声呐的非理想运动导致后向投影(Back Projection,BP)成像结果散焦的问题,提出一种结合自聚焦的后向投影成像方法。该方法首先对各脉冲回波数据进行粗栅格BP成像,然后根据图像对比度最优化准则估计出后向投影子图的相位误差,同时计算得到运动误差。最后,对相位补偿及包络搬移后的原始回波数据进行细栅格后向投影自聚焦成像,得到精聚焦图像。仿真结果表明,与传统的BP算法相比,该方法能有效改善运动误差下的多子阵SAS成像效果中显著提高点目标图像的分辨率、峰值旁瓣比及积分旁瓣比指标。Aimed at the problem of multi-receiver synthetic aperture sonar(SAS)back projection(BP)image defocus-ing caused by the imperfect motion of the platform,an improved BP imaging method combined with autofocus algorithm is proposed in this paper.Firstly,image with coarser grid for raw data of each receiver is reconstructed by BP algorithm.Secondly,the phase error of each tomographic image is estimated according to the contrast optimization criterion,and the corresponding motion error is calculated.Finally,the range-compressed echo data can be corrected by phase compensation and range profile shifts,subsequent another BP combined with autofocus is applied to get a well-focused fine grid image,which is devoid of the previously observable degradation.The simulation results show that,compared with the conventional BP algorithm,the proposed method can correct the image degradation,and significantly improve the resolution,peak side-lobe ratio and integral sidelobe ratio of the point target image.

关 键 词：合成孔径声呐 后向投影算法 自聚焦 多子阵 成像方法 

分 类 号：TB566[交通运输工程—水声工程]