双站SAR图像几何失真校正方法研究

Method for geometric distortion correction of the bistatic SAR

针对双站合成孔径雷达(SAR)中由于发射机、接收机斜视角和速度的不同导致获取图像存在几何失真的问题,提出了一种基于坐标尺度变换的双站SAR图像几何失真校正方法.首先根据双站SAR的几何关系,详细分析了目标的斜距历程.采用等效相位中心原理,将双站SAR模型等效于单站SAR模型,结合RD成像算法,建立了几何失真校正的数学模型.最后通过该数学模型,对静止二维点阵目标的成像结果进行了几何失真校正,校正结果与地面设定的场景完全一致,从而验证了该校正方法的有效性和正确性.

The existence of the differences in squint angle and velocity between transmitter and receiver in the bistatic synthetic aperture radar（SAR） makes the imaging results distorted.This paper concerns the issue of bistatic SAR image geometric correction.According to the geometry of the bistatic SAR,the slant range history is particularly analyzed.In addition,the equivalent phase center（EPC） method is used to transform the bistatic model to a monostatic equivalent.Then,the expression of the geometric distortion correction for the bistatic SAR image is derived based on the RD imaging algorithm.Finally,the validity of the method is demonstrated by simulation.