With the new very high resolution optical satellites WorldView-1 and GeoEye-1 images with 0.5m ground sampling distance (GSD) are available. By the rule of thumb of required 0.1mm GSD in the presentation scale of a topographic data base, it should be possible to generate topographic maps up to the scale 1:5000 with such satellite imagery. The orientation of WorldView-1 images is possible with sub-pixel accuracy – totally satisfying for topographic data acquisition. More difficult as before is the required accuracy of digital elevation models for the generation of ortho images if the data acquisition shall be done by on-screen digitizing of ortho images.
WorldView-1 scenes, from the city area of Istanbul and from Zonguldak, have been used for acquisition of topographic data and compared with available reference data. The mentioned rule of thumb has been confirmed – it is possible to get the details required for topographic mapping in the scale 1:5000. Both areas are partially mountainous. Together with the incidence angle of the WorldView-1 scene of 31.5°, in the build up areas larger shadow regions cannot be avoided. On the screen the shadow areas are very dark and do not allow the identification of objects even if the brightness is optimized. By Wallis filtering with a floating window of just 192 pixels a lot of details can be seen with satisfying contrast, which could not be recognized without filtering.
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