双天线干涉SAR系统无控制点场景的高精度参考相位快速估计算法

Fast estimating algorithm for high precision reference phase based on airborne dual-antenna interferometric SAR system

为解决无控制点场景参考相位的快速估计问题,对影响参考相位的因素进行理论分析,给出参考相位与影响因素的解析关系式。结合系统参数进行仿真分析,分析参考相位对高程误差的影响。根据分析结果,结合外部粗精度高程数据、滤波后的干涉相位及相干系数,提出高精度参考相位快速估计算法,并给出算法详细实现流程。对实际机载双天线干涉合成孔径雷达系统获取的数据进行处理,结果表明:算法在文中的系统参数下可以达到优于2 m的相对高程精度,处理4096×6560像素的数据块时,参考相位估计速度至少增大20倍。

In dual-antenna interferometric synthetic aperture radar system, the reference phase was usually estimated by joint calibration with transferring corresponding points for the scene without ground control points, which is too time-consuming. To solve the problem, the factors influencing the reference phase were analyzed. The analytic formula was given, and simulation was done according to the system parameters. The height error caused by reference phase was analyzed. According to the analysis results, the high precision real-time reference phase estimating algorithm was presented, combined with the extern coarse precision elevation, the filtered interferometric phase and coherence. The detailed flow of the algorithm was given. The processing results of the real data from airborne dual-antenna interferometric synthetic aperture radar system validate that a 2 m relative elevation precision can be achieved with the system in the paper by the algorithm presented, and the estimated speed can reach more than 20 times faster when processing the data of 4096 x6560pixel.