环视SAR成像处理中的几何失真校正方法

Geometric distortion correction in the circular scanning SAR imaging processing

摘要:

环视合成孔径雷达(SAR)工作于波束扫描模式，雷达天线以垂直地面方向为轴线作圆锥扫描，实现对载机周围360°范围内的聚焦成像。为了研究环视SAR成像处理中几何失真校正问题，通过波束扫描至空间不同位置处的成像几何关系，分析了成像过程中引起几何失真的机理，提出了一种基于子图像素实际地理坐标的几何失真校正方法。利用文中给出的方法对实测环视SAR数据进行处理，得到无几何失真的SAR图像，证明该方法有效。

Abstract:

Circular scanning Synthetic Aperture Radar(SAR) works in beam-scan mode，whose radar antenna conically scans with respect to the vertical direction，so that the images of full circular area around the radar platform can be formed. The geometric distortion correction of the images processed by an airborne circular scanning SAR was investigated. While the radar antenna was scanning，the imaging geometry also changed with time. After discussing the mechanism of geometric distortion，a method of geometric distortion correction based on geographic coordinate of subimage’s pixel was put forward. Live data processing validated the method proposed，and SAR image without geometric distortion was obtained.