一种俯冲段子孔径SAR大斜视成像及几何校正方法  

New Subaperture Imaging Algorithm and Geometric Correction Method for High Squint Diving SAR Based on Equivalent Squint Model

作　　者：李震宇[1] 梁毅[1] 邢孟道[1] 保铮[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,西安710071

出　　处：《电子与信息学报》2015年第8期1814-1820,共7页Journal of Electronics & Information Technology

基　　金：国家自然科学青年基金(61101245);中央高校基本科研业务费专项资金(K5051302046)资助课题

摘　　要：俯冲合成孔径雷达(SAR)成像由于垂直向下速度的存在,使得沿水平飞行方向不再满足平移不变性,导致常规全孔径成像算法无法直接运用于俯冲段的大斜视子孔径成像。针对这些问题,该文基于"俯冲等效平飞"模型以及子孔径成像特性提出一种俯冲段子孔径SAR大斜视成像算法频域相位滤波算法(FPFA)。其创新思想是通过方位频域引入滤波因子校正方位空变。由于俯冲等效平飞模型会造成成像平面的旋转,引起较大的图像畸变,为了解决该问题,该文进一步提出一种基于反向投影的快速几何校正方法,得到近似无畸变或畸变较小的地距图像。仿真和实测数据处理验证该文成像方法和几何校正方法的有效性。The ordinary full-aperture SAR imaging algorithms are inapplicable to focus high squint diving SAR subaperture data due to its property of vertical velocity which brings variance in azimuth. Based on the equivalent squint model and the characteristic of subaperture imaging, this paper explores a Frequency Phase Filtering Algorithm （FPFA） to implement high squint SAR subaperture data focusing. The innovative idea is the introduced filtering phase in the azimuth frequency domain in order to eliminate the azimuth dependence. Finally, the equivalent squint model causes the geometric deformation; due to this issue, a modified inverse-projection method corresponding to FPFA is proposed to get the final image without deformation. The simulation results and raw data processing validate the effectiveness of the proposed method.

关 键 词：俯冲合成孔径雷达 子孔径 频域相位滤波算法 反向投影 几何校正 

分 类 号：TN957.52[电子电信—信号与信息处理]