带有多普勒中心空变校正的大斜视SAR成像方法  

Imaging method for highly squinted SAR with spatially-variant doppler centroid correction

作　　者：李震宇[1] 陈溅来 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,陕西西安710071

出　　处：《西安电子科技大学学报》2016年第3期19-24,共6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：在大斜视合成孔径雷达成像中,常采用时域校正线性走动的方法来消除距离方位的耦合性,但现有的成像算法仅考虑走动校正带来的方位向调频率的空变,而忽略多普勒中心的二维空变,这将严重影响图像聚焦.文中详细分析了多普勒中心二维空变对聚焦的影响,提出一种带有多普勒中心空变校正的方位向处理新方法,提高了聚焦质量.仿真结果及实测数据验证了该方法的有效性.In the high squint SAR imaging, the linear range walk correction （LRWC） is usually adopted to mitigate the coupling between range and azimuth. The conventional algorithms only consider the effects of Doppler frequency modulation rate dependence but ignore the spatially-variant Doppler centroid; this will affect the final focusing. In this paper, the effects of spatially-variant Doppler centroid in high-squint synthetic aperture radar （SAR） are analyzed and discussed, and a modified nonlinear chirp scaling algorithm with spatially-variant Doppler centroid correction in high squint SAR azimuth processing is proposed in order to improve the quality of the final focusing. Both simulation and real data processing validate the effectiveness of the proposed method.

关 键 词：大斜视SAR 线性走动校正 多普勒中心空变 

分 类 号：TN957.52[电子电信—信号与信息处理]