一种基于高分辨率雷达影像以及外部DEM辅助的复杂地形制图方法

A DEM Mapping Method Assisted by External DEM with High Resolution InSAR Data in Complex Terrain Area

为满足在坡度陡、高差大的复杂地形地区高精度DEM制图的需要,在传统的雷达干涉测量技术的基础上,通过引入外部DEM,建立外部DEM模拟相位和干涉解缠相位的对应关系,构建多维线性模型,进行线性回归分析,去除误差相位趋势;同时根据引入的外部DEM估计高程的误差范围,进行高程点的滤波,达到精化DEM的目的,形成最终的DEM产品。该方法已经应用于高分辨雷达影像(COSMO数据)在云南德钦地区DEM地形图的制作,通过GPS数据的验证,其精度达到了国家1∶50 000 DEM制图要求。

In order to fulfill the request of digital elevation model（DEM） mapping in complex terrain areas with the remarkable height difference and steep slopes,a DEM refinement mapping approach is presented in complex terrain areas with high resolution SAR data.On the basis of interferometric synthetic aperture radar（InSAR） technology,a coarse external DEM is firstly introduced,the one-to-one correspondence between interferogram and external DEM can be determined.Then multiple linear models are established,the trend of phase error can be removed by linear regression analysis.Moreover,unreliable height points can be effectively filtered once the gross errors are determined via the error range of external DEM.Finally DEM product is constructed from reliable height points.The experiment with high resolution InSAR data of COSMO in Deqin areas in China is implemented,the final result has been validated by check points surveyed from GPS,the DEM mapping product has been proved to fulfill the standard of 1∶50 000 DEM mapping in complex terrain areas.