DEM Extraction Based On ZY-3 Stereo Pairs And AccuracyAnalysis

ZY-3 satellite is the first commercial high resolution stereo mapping satellite designed and launched by our own country, and it is mainly used to produce and update 1: 50,000 stereoscopic plotting and other basic geographic products and to survey and monitor the land and resources. DEM extracted by stereo satellite mapping has the advantages of low acquisition costs and large amount of data, so it can greatly shorten the production cycle of DEM and enhance the production efficiency and has become the current method of great value. Mozhugongka County of Tibet was selected as study area, and the DEM extraction problems were studied. The results of this thesis were as follows:Firstly, the principles and methods of DEM extraction based on the stereopair were elaborated, including relative orientation, absolute orientation and epipolar image generation and DEM extraction edition. On this basis, rigorous sensor models were compared with the characteristics of the rational function models, which explained that the rational function models had a wide range of applications.Secondly, the DEM of study area were extracted using Pix Grid software to do stereo pair image orientation, absolute orientation and epipolar line matching and DEM edition on the theory of digital photogrammetry.Thirdly, the related applications of DEM in the study area were analyzed. Using the DEM data to make the image ortho-correction and has greatly improved the imaging projection errors. The pan images and multiband images were fused and has enhanced the image information. Three dimensional display of landslide extraction information based on two phase images, and this could improve the ability to recognize landslide information, enhance the effect of landslide information.