Digital Elevation Model (DEM) Generation from Stereo Images

Digital elevation model (DEM) generation from stereo images is an effective and economical method in topography mapping. This paper used the stereo pair methodology to generate the digital elevation model (DEM) from PRISM (Panchromatic Remote-Sensing Instrument Satellite) sensor which is onboard of ALOS (Advanced Land Observing Satellite). The pair of forward-backward is used as stereoscopic imagery in this study. Ten ground control points (GCPs) are collected with residual error 0.49 pixels to generate an absolute DEM. This generated DEM with 2.5 m spatial resolution is then matched with the 90 m spatial resolution of SRTM (Space Shuttle Radar Topography Mission) DEM to compare the result. Although SRTM-DEM has a much coarser resolution, the positional accuracy of the matching is found. The difference of the height from the mean sea level (MSL) between the SRTM-DEM and the PRISM-DEM is analyzed and the correlation between the two DEMs is R2=0.8083. The accuracy of the DEM generated is given by the RMSE value of 0.8991 meter.