Digital orthophotos at a scale of 1:5000 from high resolution satellite images

This paper describes the first results of a study, carried out within the national research program “Cofin2001”, on the potential use of high resolution satellite images for making digital orthophotos at a scale of 1:5000 and 1:10,000. Particularly, images from IKONOS II and QuickBird of four different types of areas were employed: the first area is the city of Palermo, a greatly urbanized area; the second area is the extra-urban territory near the town of Contessa Entellina in south-western Sicily; the third area is the famous tourist resort of Scopello, in the western Sicily; the last area is the Caselle Airport, a flat zone near Torino. The first three images were orthorectified by using Rational Functions Model (RFM), varying the number of the GCP and using a DEM with 10 m gridcell; the last image was orthorectified by using the Toutin model and a DEM with 40 m grid-cell.