一种分段处理的大斜视SAR 成像算法

大斜视SAR 成像时，距离向和方位向严重耦合，距离走动现象明显，传统的SAR 成像算法面临严重挑战。论 文针对大斜视SAR 的成像特点，提出了一种分段处理的大斜视SAR 成像算法。该算法根据等效聚束条件进行方位分块， 在每个子块内通过距离压缩、相位补偿、距离校正和方位傅里叶变换等步骤实现子图聚焦，最后通过几何校正和子图拼 接得到条带SAR 图像。仿真结果表明，该算法能适应大斜视SAR 成像条件，获得较好的聚焦效果。

A Sectioned Imaging Algorithm for High Squint SAR

When SAR system works in high squint mode, there will be severe coupling between range and azimuth direction, moreover range walk becomes the dominant phenomenon compared to range curvature. As a result, traditional SAR imaging algorithms encounter serious challenge. Based on the characteristics of large squint SAR, the paper proposes a sectioned imaging algorithm. Using the equivalent condition of spotlight SAR, the algorithm divides SAR raw data into sub-blocks along azimuth direction. Then range compression, phase compensation, range correction and azimuth Fourier Transformation (FT) are used in turn to process each sub-block. Finally geometry correction and sub-image mosaic are adopted to get strip SAR image. Simulation results shows that the algorithm can adapt to large squint SAR, and gain good focused SAR image.