利用DEM进行多山地区星载SAR影像的正射校正

较为平坦地区的原始SAR影像简单采用二维变换函数(如多项式)即能满足精度要求，但在多山地区星载SAR影像的主要几何误差是由于地面高差引起的像点位移，用简单的多项式无法改正这项误差。以西藏墨托实验区为例，选取一定数量的控制点对，利用已有的数字高程模型(DEM)进行三维构像建立SAR影像的模拟影像，再利用模拟的SAR影像对原始的SAR图像进行正射校正。处理试验表明，利用DEM正射校正后的影像与地形图的匹配程度，比仅采用多项式选取地面控制点(GCP)进行校正的匹配程度有明显改善。

ORTHO-RECTIFICATION OF SATELLITE SAR IMAGE IN MOUNTAIN AREA BY DEM

In this paper we discussed ortho-rectification of the original SAR image in mountain area. Owing to the terrain relief,the main geometric error of the SAR image in mountain area can be rectified by polynomial. In the mountain area of MOTUO in TIBET,however, the correction steps of the SAR image are modified as follows: (1) to build the simulation of SAR image by DEM and the imaging preference; (2) to select an amount of GCPs;(3) to ortho-rectify the original SAR image. The research result shows, the method of ortho-rectify the SAR image by simulating the image with DEM is more effective than the polynomial for mountain areas.