一种基于逆问题的差分干涉SAR层析成像方法

An Inverse Problem Based Approach for Differential SAR Tomography Imaging

高度-速率维成像时,差分干涉层析成像合成孔径雷达获取的观测数据在基线-时间平面非均匀分布。若直接对观测数据进行两维傅里叶变换来恢复散射体高度-速率维像,则因强副瓣存在,成像效果不理想。该文将差分干涉层析成像合成孔径雷达高度-速率维成像问题归结为2维积分方程的逆问题,提出了一种采用Backus-Gilbert算法实现差分干涉SAR层析成像的新方法,并使用Tikhonov正则化获得逆问题的正则解。仿真结果表明该文提出的方法能够克服基线时间不均匀造成的影响,获得较好的成像结果。

When reconstructing elevation-velocity image,the observation data obtained from differential SAR tomography in baseline-time plane does not follow uniform distribution.If the elevation-velocity image of multiple scatterers is obtained using two-dimensional FFT method,the imaging result is not very good because of high sidelobes.In this paper,a new differential SAR tomography imaging algorithm is proposed based on Backus- Gilbert technique.In this algorithm,the elevation-velocity imaging is converted into an inverse problem of two- dimensional integral function,and Tikhonov regularization is used to get the regularized solution of the inverse problem.Simulation results show that the proposed algorithm can overcome the influence caused by non-uniform samples,and acquire better imaging result.