Geometric correction of satellite images using DGPS

he aim of the study is to discuss position accuracies and to examine the land use changes quickly after performing the geometric transformation of satellite images, European side of Istanbul, using DGPS (Differential Global Positioning System). In the study, the minimum number of DGPS epochs is examined to meet the acceptable accuracy of 0.5 pixels for the geometric transformation of satellite images. Separately, The Landsat 5 TM with 30 m. resolution, Spot Pan images with 10 m. resolution and IRS Pan images with 5 in. resolution are used. First, the images are transformed into UTM system using maps with 1/25 000 scale. Second, the coordinates on UTM system of control points are computed from DGPS data. The images are then transformed into UTM system using only five DGPS points. The two transformation results are compared each other. Finally, mean square errors related to the resolutions of satellite images are examined.