SAR成像阴影边缘散焦误差分析  

Error analysis for shadow edges focusing in SAR imaging

作　　者：刘琦[1,2,3] 张月婷[1,2] 胡文龙[1,2] 仇晓兰[1,2] 

机构地区：[1]中国科学院空间信息处理与应用系统技术重点实验室,北京100190 [2]中国科学院电子学研究所,北京100190 [3]中国科学院大学,北京100049

出　　处：《国外电子测量技术》2016年第4期28-33,共6页Foreign Electronic Measurement Technology

基　　金：国家自然科学基金(No.61401429);国家自然科学基金(No.61331017)项目资助

摘　　要：SAR图像阴影散焦误差分析是研究阴影再聚焦和提取目标阴影信息的理论基础。从阴影形成机理出发,以距离多普勒算法以例,推导阴影边缘二次距离压缩和方位压缩的二次相位误差表达式,建立了散焦误差与成像参数的关系模型。研究表明,方位压缩和二次距离压缩分别是影响阴影边缘散焦的第一环节和第二环节,其散焦误差与雷达频率、分辨率、目标高度有关。当X波段、Ku波段雷达的分辨率劣于0.07m时,方位压缩的阴影边缘散焦误差将达到总误差的99.0%以上,只需进行方位向再聚焦;当Ku波段雷达的分辨率优于0.04m时,则需要同时优化方位压缩和二次距离压缩环节。The shadow edges in SAR images are blurred.The error analysis for shadow edges defocusing is the theoretical basis of the shadow refocusing and target shadow information extraction.Taking the range Doppler algorithm for example,shadow quadratic phase errors of secondary range compression and azimuth compression are deduced in this paper according to the formation mechanism of shadow,which establish the relationship between the defocusing error and imaging parameters.The azimuth compression is the main step to affect the defocusing error,while secondary range compression is another.The defocusing error is related to the radar frequency,the radar resolution and the height of the target.For the X-band and Ku-band radar with a resolution worse than 0.07 m,the focusing error of the shadow edges caused by the azimuth compression would reach 99.0% of the total errors,where the refocusing in azimuth is required.When the resolution of the Ku-band radar is better than 0.04 m,the optimization of azimuth compression and secondary range compression are both required.

关 键 词：SAR图像 阴影 散焦 误差 成像环节 

分 类 号：TN959[电子电信—信号与信息处理]