DEM Extraction From IRS-P5 Stereo Pairs In Earthquake Disaster Area And Its Applications

As an important component of geo-spatial information infrastructure, DEMs have played an important role in various fields associated with the terrain. It has a very important significance to study its production and application for its broad prospects.At present, the main ways to obtain DEM are: ground measurements method, the paper map digitization method, space-sensors based methods and digital photographic methods. Digital photogrammetry is the most common way. It mainly through the stereo image pairs to restoration the original three-dimensional shape and generate DEMs by three-dimensional measurement on the model.With the development of related technologies, remote sensing data is stable and low cost, thus shorten the DEM production cycle and improved the efficiency. Rresearchs on DEM extraction of high-resolution satellite data, such as ASTER, SPOT, IKONOS, QuickBird are deep at home and abroad. However, it is very rare to see researching on DEM extraction and application from IRS-P5 stereo pairs which India launched in 2005.Wenchuan earthquake resulted tremendous landscape changes. DEM is an indispensable important information for study geological disasters such as landslide disaster. But the original DEMs and other basic surveying and mapping datas were not time-sensitive. For that reason, to satisfy the disaster relief decision-making and post-disaster reconstruction, it is of great significance to access DEM data of disaster areas in time.As its own complex features of the high-resolution imaging satellite developed recently, more and more commercial satellites began only to provide the necessary parameter information for rational function model. Therefore, approximate sensor model has been applied gradually. The major research works are shown as follows:(1) The paper discusses the concept, characteristics, solution method and the production process of rational function model.(2) Obtain DEMs of experimental zone from IRS-P5 stereo pair on the platform of ENVI software. It attempted to extract DEM of no ground control points of high-precision and compared the result wit h the 1:50000 existed DEM. The root mean square error of 2007 DEM can reach 14.35m, while of 2009 DEM can reach 18.58m. Both achieve the DEM accuracy index of 1:50000.(3) Producing DOMs of disaster area based on DEMs and aft-looking images. Data can be used for topography analysis, land cover change detection of damage area. Research can contribute to advancing the application of IRS-P5 DEM.