[en] The purpose of the presented research project is to investigate how present-day EO-technology can support local and regional decision-making, particularly in Belgium, and to develop prototype versions of value-added products that fulfill some of the actual information needs, as expressed by Belgian authorities at the local and at the regional level. One of the technical research modules is focussing on the geometrical aspects of VHR data processing.
Due to the capability of the IKONOS sensor up to an angle of 26° off-nadir, the satellite can take stereo image pairs. An IKONOS stereo pair consists of two images of the same location taken from two different perspectives on the same orbital pass. Although it is possible to obtain a stereopair from two images from different orbital passes and with a large time interval, it is proved that the stereopairs ordered from Spaceimaging or resellers gives better results (2004, Taillieu et al.).
This paper describes the method applied for DSM generation from an IKONOS stereopair, over an urban area. The geometrical accuracy of the DSM is compared with the accuracy of a DSM, derived from aerial photography at scales of 1:12000 and 1:4000. The satellite-derived DSM is used for ortho-rectification of VHR imagery. The accuracy of the ortho-rectified images is compared with ortho-rectifications of the same images, based on the aerial photo DSM.
