A SRTM-DEM-controlled Ortho-rectification Method for Optical Satellite Remote Sensing Stereo Images

In response to the problem of lacking of control base in the project of global mapping, a method to ortho-rectify satellite remote sensing images is proposed, which uses SRTM-DEM as control base. First, stereo images pairs which compose of optical images are adjusted by block adjustment of free networks and DEMs are extracted.Then SRTM-DEM is used as control base, the single DEM is the cell model and DEM block adjustment of independent models is implemented to get orientation parameters of each model.Finally, the geometric model parameters of each stereo image pair are corrected to ortho-rectify the nadir image. The ZY-3 images in Xianning and Jiangxi are taken as test data and the results show that the planar orientation accuracy of the pan nadir image is improved from 12.93 pixels to 6.85 pixels.