Handling of High Resolution Space Images in Z/i Imagestation

High resolution space images are becoming more and more important as their resolution and availability improve. Images having a ground pixel size of 0.6 m or 1.0 m are competing with classical aerial photos. The space images cover large areas, reducing the number of control points needed. If rational polynomial coefficients (RPC) are available, the number of control points can be reduced even further. Using RPCs, mapping is also possible without control points if only relative accuracy is required, and if an absolute accuracy in the range of a standard deviation of ±12 m is acceptable. Stereo models and individual images taken by IKONOS, QuickBird and SPOT 5 have been analyzed, as well as IRS-1C level 1B and Landsat images. The achieved accuracy is sufficient for mapping and orthoimage generation. Digital surface models (DSM) are generated by image matching, showing the height of the visible surface. DSMs can be reduced to digital elevation models (DEM), which can be used for producing orthoimages. It is not necessary to use the same sensor for achieving the DEM, so it is possible to compute an IKONOS orthoimage based on a SPOT 5 DEM.