Generation and validation of digital elevation models based on satellite images

Büyüksalih G., Jacobsen K.

Revue Francaise de Photogrammetrie et de Teledetection, no.184, pp.17-22, 2006 (Scopus) identifier


Digital elevation models (DEMs) are available free of charge for most areas of the world. For example the C-band height model of the Shuttle Radar Topography Mission (SRTM) has with a standard deviation of 3m to 5m for flat and open areas accuracy sufficient for several cases, but the spacing of 3 arcsec is causing a loss of morphologic information in mountains. Even with quite less accurate DEMs based on ASTER, more morphologic details can be achieved. With the very high resolution satellite images a higher accuracy and quite more details than with the SRTM DEM can be reached. In open areas the vertical accuracy is linear depending upon the height-to-base-ratio, but in the city this is quite more difficult. With a height-to-base-ratio of 1.0 in the city the corresponding image details of the high resolution scenes are too different, so that only a limited percentage of the model points can be matched automatically. The optimal convergence angle is quite smaller. In addition with a height-to-base-ratio dose to 1.0 only few points on the street level can be achieved in densely build up areas. Different types of satellite image models have been analysed for completeness, accuracy and morphologic details in relation to a reference DEM based on large scale photogrammetry.