Accuracy analysis of remote sensing image rectification

Position accuracy is the base of remote sensing image application. In this paper, the effect of the number, the distribution and the accuracy of ground control points (GCPs) and DEM in different scales for the image rectification is analyzed in detail. Quantitative evaluation of orthoimage is performed. The mathematical functions for calculating the position accuracy of the orthoimage are given based on different georeference information. The relation between the final accuracies of orthoimages and the accuracies of GCPs and DEM is analyzed based on the experiment results. It shows that accuracies of the checked orthoimages coincide with the calculated accuracies. The final accuracy can be estimated with the method described in this paper if the accuracy of control data is known. On the other hand, if the final accuracy of the orthoimage were determined, the least requirements for the accuracies of GCPs and DEM could be calculated by the mathematical functions.