一种基于DEM的机载干涉相位生成算法

Algorithm for the generation of airborne interferometric phase based on DEM

为生成基准干涉相位图用于干涉合成孔径雷达（interferometric synthetic aperture radar,InSAR）辅助惯导系统导航,提出了一种基于数字高程模型（digital elevation model,DEM）的机载干涉相位生成算法。该算法利用惯性测量单元（IMU）得到轨迹信息,根据SAR成像参数确定成像区域,并对成像区域内的基准DEM数据按斜距进行重采样,然后将重采样后的DEM结合InSAR成像几何模型来生成基准干涉相位。最后利用山地区域的仿真数据和存在斜视角情况的实际InSAR数据,通过将本文提出的相位生成方法与InSAR系统获取的相位进行对比,仿真数据相位误差在0.000 5rad左右,实测数据相位误差在0.001 4rad左右,进而验证了提出的相位生成算法的有效性。

In order to generate the referenced interferometric phase for the interferometric synthetic aperture radar（InSAR）aided navigation system,an airborne interferometric phase generation algorithm based on digital elevation model（DEM）is proposed.In this algorithm,the imaging area is determined by the trajectory information obtained from the IMU and the SAR imaging parameters.The referenced DEM data in the imaging area is resampled according to the slope distance,and the resampled DEM combined with the InSAR imaging geometric model are applied to generate the referenced interference phase.Finally,with the help of simulation data of mountains and actual InSAR system data with squint angle,we compare the interferometric phase generated by the proposed algorithm with the phase obtained by InSAR.The phase error of the simulation data is about 0.000 5 radians,and the phase error of the actual data is about0.001 4 radians,and the validity of the proposed phase generation algorithm is verified by the experiment results.