利用回波数据的高分宽测机载SAR运动误差提取方法

Motion error extraction method for airborne high-resolution and wide-swath SAR imaging using echo data

为实现高分辨宽测绘带SAR成像,提出一种基于回波数据的高分辨宽测绘带机载SAR运动误差提取方法,有效弥补了基于惯性测量单元/全球定位系统(INS/GPS)提取的运动误差精度低的问题.首先采用一种基于图像对比度最优的方法对SAR回波数据进行相位误差估计,然后利用加权总体最小二乘(WTLS)基于空变相位误差模型反演运动轨迹误差,最后利用得到的轨迹信息实现空变相位误差的补偿和残余距离徙动校正.实测数据处理结果证明该方法有效,相比传统自聚焦算法具有更高的估计和补偿精度.

In order to achieve high-resolution and wide-swath SAR imaging,this paper proposes a method of motion error extraction based on echo data for airborne high-resolution and wide-swath SAR imaging,which effectively compensates for the low measurement accuracy of motion error extracted from inertial navigation system/global positioning system(INS/GPS).Firstly,a method based on image contrast optimization is used to estimate the phase error of SAR echo data,and then the trajectory error is retrieved by weighted total least squares(WTLS)based on range-dependent phase error model.Finally,the compensation of range-dependent phase error and the residual range cell migration(RCM)correction can be realized by using the trajectory information obtained.The processing results of airborne SAR real data are presented to demonstrate the validity of the proposed algorithm.Compared with the traditional autofocus methods,this algorithm has better estimation and compensation accuracy.