Title: EFFICIENT AUTOMATED DIGITAL AERIAL TRIANGULATION THROUGH CUSTOMISATION OF A COMMERCIAL PHOTOGRAMMETRIC SYSTEM
Abstract: Aerotriangulation is one of the key processes in digital photogrammetric production which has the highest potential for automation and efficiency. In this paper, we introduce a customised and modified approach to aerial triangulation using the Helava Automated Triangulation System (HATS) as the basic triangulation measurement tool. This presented approach is currently in use at Swissphoto Vermessung AG, former swissair Photo+Surveys Ltd., for the aerial triangulation of the swissphoto block with more than 7000 images covering the entire area of Switzerland. The highly automated and efficient digital aerotriangulation (AT) approach and results of four Swiss photogrammetric triangulation blocks are presented in this paper. The four blocks used vary between 150 and 270 images (photo scale 1: 27’000) and each block represents different terrain characteristics. All measurements were carried out in greyscale images with a resolution of 25 micron on the Helava/Leica Digital Photogrammetric Workstation DPW670 using a very dense tie point pattern. The observations were later adjusted in the GPS supported bundle adjustment program BLUH using self-calibration. The RMS of the control points was about 0.5 m in planimetry and about 1m in height, while the RMS values of the GPS station co-ordinates were better than 0.5 m in planimetry and 0.2 m in height. With this introduced customised triangulation approach the used time for triangulation is up to 8 minutes per photo, if only the operator-intensive work is summarised, while computation time of the computer, which is mostly done overnight, is neglected. The aspects of terrain characteristics with respect to triangulation performance will be also discussed in this paper.
Publication Year: 1997
Publication Date: 1997-01-01
Language: en
Type: article
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Cited By Count: 5
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