为了研究多基线InSAR技术,充分利用长、短基线互补的优势来提高获取DEM的精度及可靠性,设计了一种多基线InSAR干涉图的直接法仿真方案。该方案采用正侧视成像模型,由F Leberl方程建立地面点坐标与像点坐标之间的关系,并针对机载多天线InSAR系统构成的多基线模式,直接由DEM中记录的地面点3维坐标计算像点坐标和干涉相位,再对干涉相位进行重采样以得到像点规则排列的干涉图。采用多套DEM进行了多基线InSAR干涉图的仿真实验,得到了较满意的结果,验证了所设计仿真方案的正确性和有效性。
A direct algorithm for simulation of multi-baseline interferograms was designed to study multi-baseline InSAR, which was used to improve the precision and the reliability of derived DEMs by combining the advantages of both longer and shorter baselines. The boresight imaging model was adopted, and the relations between coordinates of pixels in interferograms and coordinates of ground points was established with F Leberl formula. The coordinates and the interferometric phases were calculated directly with 3 dimensional coordinates of ground points in DEMs. The interferometric phases were resampled to derive interferograms with regular pixels. Muhi-baseline interferograms were simulated with different DEMs and the results are satisfying. The simulation algorithm was validated.