Digital aerial triangulation with the Helava Automated Triangulation System

Presents investigations and results on a digital aerial triangulation of two Swiss test blocks using the Helava Automated Triangulation System (HATS). In a pilot study, digital image data scanned with a resolution of 25 μm, from the block St. Gallen/Appenzell including 109 b/w images and from block Zug (82 b/w images), both at a photo scale of ca. 1:27 000, was triangulated. All observations were later adjusted in the GPS supported bundle adjustment program BLUH using self-calibration. The empirical accuracy from check points, which had not a very good quality due to their various sources, was better than 1 m in planimetry and about 1.3 m in height using GPS photo centre coordinates and sparse ground control information in the combined adjustment. The RMS values of the GPS station coordinates were about 0.6 m in planimetry and 0.3 m in height.