环视SAR成像处理中的几何失真校正算法  

Geometric Distortion Correction Algorithm for Circular-Scanning SAR Imaging

作　　者：李勇[1] 朱岱寅[1] 朱兆达[1] 

机构地区：[1]南京航空航天大学信息科学与技术学院,南京210016

出　　处：《南京航空航天大学学报》2009年第2期232-237,共6页Journal of Nanjing University of Aeronautics & Astronautics

基　　金：教育部高校博士点基金(20070287053)资助项目;航空科学基金(20080152004)资助项目

摘　　要：环视合成孔径雷达(SAR)图像用于导弹精确末制导中的景象匹配处理,需要满足几何精度的要求。校正由雷达平台不规则运动和天线圆周扫描导致的图像几何失真,是环视SAR成像处理中的关键步骤。文中在利用线性距离多普勒算法生成子图像的前提下,提出了一种基于像源与像点映射关系的距离多普勒域图像几何失真校正算法。该算法无需复杂的坐标系转换计算,实现了360°范围内任意波束指向上SAR子图像几何失真校正。地面点目标仿真和实测数据成像结果证明了该算法的有效性。The images generated by a missile-borne circular-scanning synthetic aperture radar can provide precise guiding information though image-matching processing to satisfy their high precision demands in geometry. However, due to the irregular motion of the radar platform and the circular-scanning antenna beam, the inevitable geometric distortion on the focused images is necessary to be corrected. A two-dimensional geometric distortion correction algorithm is presented based on projection transformation be-tween the scatterers and the images under the condition of focusing the subimages using linear range-Doppler algorithm. The geometric distortion on any subimage obtained at any squint angle within 360° can be effectively corrected to avoid any complicated coordinate calculations. The point-target simulations and live data imaging results prove the validity of the algorithm.

关 键 词：合成孔径雷达 环视模式 几何失真校正 图像聚焦处理 景象匹配 

分 类 号：TN957[电子电信—信号与信息处理]