对山地和高山地等选点困难地区的星载SAR影像进行正射纠正时,通常采用距离多普勒模型进行影像模拟纠正。但由于每类星载SAR影像辅助数据不同,所建立的距离多普勒模型均不相同,从而导致针对每类星载SAR影像需要采用不同的软件模块进行模拟和正射纠正。针对该缺点,采用RPC模型代替距离多普勒模型并利用改进的模拟影像灰度确定方式进行星载SAR影像模拟,在此基础上建立模拟影像和真实SAR影像之间关系进行正射纠正。采用四川某地区的TerraSAR-X影像,将正射纠正的实际精度和理论精度进行对比,验证本文提出的理论和方法。
SAR image ortho-rectification in the areas where it is difficult to select points,such as hilly and mountainous terrain,often adopts the method based on the image simulation.The traditional method used the RD model to do the simulation but it needed to establish different modules to do the simulation and ortho-rectification for different SAR images.This paper proposed the method using the RPC model substituting the RD model to simulate the SAR image in order to address the problem and did the ortho-rectification with the simulated image.Also,this paper improved the method of obtaining gray information from the simulated SAR image.TerraSAR-X images acquired over Sichuan were used as test data.Through the comparision between the actual accuracy and the theoretical accuracy of the ortho-rectification image,the theory and method proposed in this paper were verified.