Aerial triangulation over urban areas with control points auto- extracted from existing AT results

Abstract

For the purpose of improving the efficiency of GIS data-updating over urban areas, a new approach of aerial triangulation (AT) with ground control points auto extracted from the existing AT results is introduced in the paper. The existing AT results mean the existing aerial imagery with interior and exterior orientation parameters. Through a multi-views image matching between the new aerial photos and old photos, enormous ground control points could be auto extracted and their ground coordinates could be calculated by the forward-intersecting of old aerial photos. The efficiency and accuracy of the method have been tested and analysed with several actual aerial imagery blocks. The experiment results presented in this paper shows that the method could not only extract enormous GCPs automatically which lead to a greatly improvement of the efficiency of AT over urban areas, but also achieve the same level of accuracy of the old AT results.