宽测绘带星载环视扫描SAR成像方案研究

环视扫描合成孔径雷达（Synthetic Aperture Radar, SAR）可以实现广域观测，但测绘带宽受到最小天线面积的限制，对此提出了一种宽测绘带星载环视扫描SAR成像方案。该方案引入了ScanSAR的波束扫描思想，在雷达天线作圆锥扫描的同时，由近及远地对多个距离子带进行分时扫描。给出了天线在这种扫描方式下的驻留时间分配准则，分析了成像参数间的依赖关系。基于子孔径成像、几何失真校正和图像拼接的一系列成像算法对该宽测绘带方案进行了点目标和面目标仿真实验，结果表明在保证成像质量的前提下，测绘带宽能得到显著的增加。

Study on Wide Swath Imaging Method for Spaceborne Circular-Scanning SAR

Circular-scanning synthetic aperture radar can observe the scene information on both sides of the track simultaneously, but the mapping bandwidth is limited to the minimum SAR antenna area. A wide swath spaceborne circular-scanning SAR imaging method is proposed. As the antenna scans conically, it also scans periodically in each strip to get wider swath. The strip residence time distribution rule and imaging parameters of this mode are discussed. A series of imaging algorithm, including sub-aperture imaging, geometric distortion correction and image mosaicking, is applied to the point target and the distributed targets simulation experiments. The imaging results show that under the premise of good image quality, the swath gets significantly increased.