Il sistema GPS per il rilevamento del territorio: potenzialità e limiti dei diversi metodi di acquisizione

The purpose of this paper s to present a summary of the potential and the limits of the use of Satellite Positioning Systems in the field of archaeological research and, more generally, in the construction of numeric models describing the territory. In the first section we will examine the various methods of acquisition, with emphasis on the measuring time and the level of accuracy in the different applications. In the second section we have presented some study cases, in particular the research conducted in collaboration with the Department of Medieval Archaeology of the University of Florence regarding some castles in Crusader era Ayyubid Transjordan (valley of Petra, Castle of Shawbak) and the results of the project entitled "The necropolis of Colle del Forno" conducted by the CNR and by the Archaeological Superintendence of Latium. In the first case a 3D reconstruction of the rock formation on which the villages being studied are built is illustrated. Moreover, for the Castle of Wu'ayra, we have given a description of the system utilized for the photographic coverage of the village, obtained with images taken from a low-flying kite and geo-referenced with GPS. In the case of Colle del Forno, in order to evaluate the accuracy of the results in relationship to the time required for the realization, the survey made by GPS in cinematic mode and that made with total station are compared. In this way we hope to contribute to the choice of strategies to be employed focusing on the costs and benefits of the different methods which can be use.