基于ISAR和相位恢复的SAR运动目标成像方法

针对合成孔径雷达(SAR)对运动目标成像时出现移位、散焦问题,本文提出一种基于相位恢复原理和ISAR算法的相位误差校正方法。该方法首先从SAR图像中提取包含运动目标的子图像并反演得到回波域数据;然后,采用自适应时间窗算法(Automatic time-windowing)以及图像对比度算法(ICBA)对误差相位进行粗补偿;最后,利用相位恢复算法迭代求解实现对相位的精确补偿。该方法利用粗补偿得到的模糊图像信息作为相位恢复算法的先验条件,提高了算法的收敛性,仿真实验结果验证了该方法的有效性。

SAR Moving Target Imaging Method Based on ISAR and Phase Retrieval

 For the problem of shift and defocusing in SAR moving target imaging, a motion compensation method based on phase retrieval principle and ISAR algorithm is proposed. Firstly, the sub-image is selected from formed SAR image, and the original data of the ISAR processing obtained by inversion mapping. Then, the Automatic time-windowing algorithm and the Image Contrast-based Autofocus (ICBA) algorithm are adopted to compensate the error phase. Finally, the phase retrieval algorithm is used to achieve accurate phase compensation. The method exploits the fuzzy image information obtained by the coarse compensation as the a priori condition of the phase retrieval algorithm, which improves the convergence of the algorithm. The simulation results demonstrate the validity of the proposed algorithm.