基于InSAR视角对基线精度的影响分析

摘要

干涉合成孔径雷达中存在的基线误差会严重影响高程测量的精度问题。由于地球曲率的存在，地物点参考椭球半径在不同纬度地区与星下点的地球半径存在较大的差异，给出了雷达视角与基线的关系式。从雷达临界视角的角度，给出了临界基线的公式。结果表明在一幅影像图上，用一个点的基线值代替整张影像的基线值所产生的误差会传播到DEM以及形变的结果中。%In the InterferometricSAR, the existence of the baseline error and height error of the satellite will affect the precision of the altitude information transformed from the interferometric phase.As the existence of earth curvature, Reference ellipsoid radius of the feature points have great difference with the ellipsoid radius of subsatellitepoint, the relationship between radar angle and baseline is presented.From the radar critical angle, the formula of the critical baseline is deduced.The results indicate that the error will be propagated to the DEM and the deformation results if a point of baseline value replaces the whole image of the baseline value in a shad-owgraph.