1 ACCURACY ANALYSIS, DEM GENERATION AND VALIDATION USING RUSSIAN TK-350

TK-350 stereo-scenes covering 200x300km on the ground with base-to-height-ratio of 0⋅52 have been analysed on Zonguldak testfield in the northwest of Turkey. The pixel size on the ground is 10m. Control points were digitised from 1:25 000 scale topographic maps have been used in the test. The bundle orientation was executed by the Hannover University program system BLUH and PCI Geomatica OrthoEngine AE software package. TK-350 stereo-images can yield 3D geopositioning to an accuracy of about 10m in planimetry and 17m in height. Based on these scene orientation, DEM with 40m cell size was generated by the related module of PCI system. For the validation of extracted DEM, matched data was checked against the reference DEM based on the digitised contour lines from the 1:25 000 scale topographic maps. This comparison show that accuracy results depend mainly on the surface structure and terrain slopes. Root mean square errors for Z were found to be about 27m and 39m outside and inside the forest area respectively. Matched DEM presents some systematic shifts against the reference DEM which are also visible in asymmetric shifts of the frequency distribution. 2 KEY WORDS: Russian TK-350 images, geometric accuracy testing