弹载SAR子孔径大斜视成像方位空变校正新方法  

New method for azimuth-dependent correction of highly squint missile-borne SAR subaperture imaging

作　　者：李震宇[1] 杨军[1] 梁毅[1] 邢孟道[1] 

机构地区：[1]西安电子科技大学雷达信号处理国家重点实验室,陕西西安710071

出　　处：《西安电子科技大学学报》2015年第4期88-94,197,共8页Journal of Xidian University

基　　金：国家自然科学基金资助项目(61101245);中央高校基本科研业务费专项资金资助项目(K5051302046)

摘　　要：斜视成像是弹载合成孔径雷达(Synthetic Aperture Radar,SAR)的一种重要工作模式,从实际应用出发,弹载SAR为实现快视成像常采用子孔径处理.由于在大斜视模式下,距离方位严重耦合,常规算法成像处理的第1步是采用时域校正距离走动的方法来消除距离方位的耦合,这会带来方位相位随方位位置空变问题,造成方位无法统一处理,影响方位聚焦深度.文中详细分析了弹载SAR大前斜瞬时斜距模型,针对子孔径数据,提出一种基于高次相位滤波的方位空变校正新方法,实现方位统一聚焦处理.点目标仿真数据处理验证了文中所提方法的有效性和实用性.Squinted imaging is one of the most important modes in the missile‐borne synthetic aperture radar （ SAR） . Usually , from the view of practical applications , the missile‐borne SAR adopts subaperture processing in order to implement quick look imaging . In the highly squint mode , the echo signal couples greatly between range and azimuth , so traditional algorithms perform the linear range walk correction in the azimuth time domain firstly to mitigate greatly the range‐azimuth coupling , which causes the problem of position dependent azimuth phase , resulting in the azimuth uniform processing disabled and impacting the azimuth depth of focus （DOF） . Based on the deep analysis of the instantaneous slant range model in the highly squint missile‐borne SAR , this paper proposes high‐order phase filtering to correct azimuth‐dependence for implementing the identical azimuth‐focusing processing . Simulation results validate the effectiveness of the proposed algorithm .

关 键 词：斜视成像 弹载合成孔径雷达 子孔径 聚焦深度 高次相位滤波 

分 类 号：TN957.52[电子电信—信号与信息处理]