The main aim of this research is to investigate the impact of vertical accuracy of digital elevation models (DEMs) on the orthoimage production process. The study took place on a QuickBird image by using four different DEMs with different vertical accuracies, nine ground control points (GCPs), and three sensor models. The four DEMs are global positioning system (GPS)-based DEM, topographic map–based DEM, Shuttle Radar Topography Mission-based DEM, and advanced spaceborne thermal emission and reflection-based DEM. The used sensor models are the rigorous sensor model, rational functional model (RFM), and refined RFM. The results show that the RFM without GCPs gives inaccurate
results especially in case of high spatial resolution satellite images. The research recommends using the rigorous model and the refined RFM for orthorectifying images accurately as the results
showed that these two models give accurate, precise, and stable results. As well, their results do not contain systematic errors. |
