XXIII FIG Congress, Germany, pp.1
With the development of technology Digital photogrammetry has been started to be used widely in almost all area about mapping. Especially digital orthophotos which are a photogrammetric products, are being used common by lots of private sectors because of theirs easy interpretability. This has increased the demand on maps and has led to the need of researching on about accuracies. The resolution and the scale of the used aerial photos or satellite images, the quality and the scale of the DEM (Digital Elevation Model) and land topography are some of the factors that affect the accuracy of the orthophotos. The affects of the DEM and land topography on orthophoto accuracy have been investigated in this study. Firstly the affects of DEM on orthophoto maps which are produced either by aerial photos or satellite images has been investigated. Secondly, to determine the affect of topography on the process, some scanned aerial photos and the panchromatic (PAN) band of IKONOS satellite have been used. These scanned aerial photos are belong to the different regions in Turkey like Trabzon, Aydın, Tekirdağ ve Siirt, with different scales and resolutions (14μm-21μm) and they also represent different topography properties (rough, flat). Then the orthophoto maps, generated by using these inputs, have been compared with each other through their accuracies and coherences.