In-depth investigations of parameters influencing the accuracy of orthoimages from high resolution satellites

Abstract

Orthoimages are the most popular product from high spatial resolution satellite sensors. Various investigations, especially regarding Ikonos and Quickbird, have been published and achieved accuracies reported. However, these investigations are based on different input parameters (density and accuracy of DTM, number, distribution and accuracy of GCPs, sensor model, range of heights in the area, sensor elevation, type, amount and accuracy of information used to check the planimetric accuracy) and thepublished results are thus not comparable. Furthermore, the influence of the above mentioned parameters on the planimetric accuracy of the orthoimages has not been analysed using one common consistent dataset. In this work, we will try to cover this gap. In previous publications, we have presented a comparison of point positioning accuracies using various sensor models and different number and distribution of GCPs, so these aspects will not be treated in this work. Here, we have used in all cases as sensor model RPCs with a subsequent affine transformation and a small number of GCPs (8) with homogeneous distribution. The aspects that we analyse here is the influence of (a) the DTM, (b) the source and accuracy of GCPs, and (c) the sensor elevation.