GPS/INS Systems for compilation of digital large-scale orthophotos

The paper describes the first results of a study, supported by an Italian research project “Integrated Inertial Positioning Systems in Aerial Photogrammetry” on the potential use of these techniques for production of digital large scale orthophotos. The study has been done with aerial photographs collected from two different flights executed in Sicily: the former, relating to the city of Palermo, at average scale of 1:9300; the latter, over the city of Catania, at average scale of 1:2000. For both flights the orthorectification was carried out by direct georeferencing methods and by traditional photogrammetric techniques, using ground control points surveyed by means GPS techniques and aerial digital triangulation. The orthophotos generated by both methods were compared between themselves checking the influence of integrated sensors on the accuracy of the final product.