一种新的基于瞬时干涉的SAR-GMTI精聚焦和定位方法

摘要

在合成孔径雷达地面运动目标检测(SAR-GMTI)中，由于场景中多个运动目标运动参数不同且在合成孔径时间内运动参数随时间变化，因此常规算法较难有效解决动目标信号的距离徙动(RCM)和方位散焦问题，难以实现动目标的精聚焦，从而影响动目标定位精度。该文提出一种基于瞬时干涉的动目标精聚焦和定位方法。首先提取单个动目标信号，精提取瞬时干涉相位(IIP)并结合径向速度解模糊得到动目标瞬时径向速度，经过距离徙动补偿并最终实现动目标的精聚焦，提高动目标定位精度。实测数据处理结果验证了该方法的有效性。%In Synthetic Aperture Radar-Ground Moving Target Indication (SAR-GMTI) processing, it is difficult to solve the Range Cell Migration (RCM) and azimuth defocusing problems simultaneously since the motion parameters of each moving target is different, which makes the high-accuracy focusing of moving target unattainable, thus affects the accuracy of positioning. A high-accuracy focusing and positioning of moving-targets method based on instantaneous interferometry is proposed in this paper. Firstly, single moving target can be extracted. After that, by iteratively extracting the high-accuracy Instantaneous Interferometric Phase (IIP) of moving target and solving the across-track velocity ambiguity, accurate across-track velocity can be obtained and utilized in RCM removing. After all, high-accuracy focusing of moving target can be achieved, which improves the accuracy of positioning. The processing results of measured data illustrate the effectiveness of the proposed method in this paper.