双天线干涉SAR系统无控制点场景的参考相位高精度快速估计算法

在双天线干涉SAR系统中，对无控制点的场景通常采用同名点传递的联合定标方法估计参考相位，非常耗时。为解决无控制点场景参考相位的快速估计问题，本文首先对影响参考相位的因素进行理论分析，给出了参考相位与影响因素的解析关系式，并结合系统参数进行了仿真分析；进而分析参考相位对高程误差的影响。根据分析结果，结合SRTM的粗精度DEM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，并给出了算法详细实现流程。通过对实际机载双天线InSAR系统获取的数据进行处理，表明本文算法在文中的系统参数下可以达到优于2m的相对高程精度，处理4096×6560的数据块时，参考相位估计速度要快20倍以上。

Fast Estimating Algorithm for High Precision Reference Phase Based on Airborne Dual-antenna InSAR System

In dual-antenna interferometric SAR system, the reference phase is usually estimated by joint calibration with transferring corresponding points for the scene without GCPs, which is too time-consuming. To solve the problem, the factors influencing the reference phase are analyzed firstly, the analytic formula is given, and simulation is done according to the system parameters. Then, the height error caused by reference phase is analyzed. According to the analysis results, the high precision real-time reference phase estimating algorithm is presented, combining with coarse precision DEM of SRTM, the filtered interferometric phase and coherence. In addition, the detailed flow of the algorithm is given. The processing results of the real data from airborne dual-antenna InSAR system validate 2m relative DEM 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 4096×6560.