Accuracy assessment of the effect of digital elevation models generated from different sources on orthophoto

The aim of this study is, to search the effects of the differences in production method of Digital Elevation Model (DEM), which is one of the source data in ortophoto production, as well as in grid intervals and input data, on the accuracy of the ortophoto that is produced by those data. The difference between this application and those the previous ones is the source data that is used. 1:60.000 scaled digital aerial photographs, SRTM data at 3"x 3" intervals and dijital contour lines at 10 m. intervals have been used during the study. At block adjustment stage, Ground Control Points in four different quantity have been included and four different photographs have been obtained for every investigation of triangulation mark. DEMs have been produced by means of Digital Image Matching technique from Digital Aerial Photograps while by means of raster technique from SRTM and contour lines. In ortophotos that are produced from those data; readings had been implemented on permanent triangulation points that were established on working area before, and obtained values had been analyzed through the comparison with the adjusted coordinate values. Again in the same working area, specific points have been chosen on a region that has diverse land characteristics, and coordinate values of those points have been read from the stereo model by way of approaching to land surface excellently. Afterwards, values of the same points that were read from ortophoto had been examined through comparison.