基于DEM的星载SAR图像模拟以及用于图像精校正

根据星载SAR的距离-多普勒成像原理对DEM的三维位置点进行成像几何位置的计算,然后根据经验公式给出了雷达后向散射系数的模拟方法。针对DEM格网间隔和SAR图像分辨率的不同,以及由于侧视成像雷达的特点而导致山区的迎坡和背坡模拟图像点密度不均匀等问题,采用了基于DEM格网点内插的算法。最后应用模拟的SAR图像和真实图像匹配来实现星载SAR图像的几何精校正处理。通过采用RADARSAT的实际图像进行了图像的模拟和几何校正,证明了方法的可行性。

Space-borne SAR Image Simulation and Its Application in Geo-rectification

The image position of space-borne SAR is calculated based on range-doppler principle and then the scatter coefficientof terrain is simulated according to experientialformula.The(density)of simulated image points in mountain is not symmetricalowing to the difference between the interval of DEM and the resolution of SAR image,and side-look character of SAR.Four DEM corner points are used to interpolate the simulated SAR image.The space-borne SAR is rectified(after) thatthe simulated image is matched with the real SAR image.The method is demonstrated by simulating RADARSAT image and rectifying the real SAR image.