DSM Generation from IKONOS Stereo Imagery

Abstract

Digital surface model generation from IKONOS stereo imagery is a new challenge in photogrammetric community, especially when the satellite company does not provide the raw data as well as their ancillary data. The IKONOS stereo images are provided in a quasi-epipolar geometry reference where only the terrain parallax in the scanner direction remains. A rigorous solution for orbit modeling is not practical. In this paper we utilized an estimated relief displacement azimuth and the nominal collection elevation data included in the metadata file to correct the relief displacement of GCPs, together with a linear transformation for geometric modeling of IKONOS imagery. Conjugate point correspondence problem is solved by a multi-resolution template-based image matching technique. Space intersection is performed by the trigonometric intersection assuming a parallel projection of IKONOS imagery due to its small FOV and frame size. In the experiment, less than 2-meters of RMSE is achieved denoting the potential positioning accuracy of the IKONOS stereo imagery.