Impiego di immagini satellitari ad alta risoluzione nel monitoraggio dell’erosione costiera

To plan operations for stopping or at least limiting effects of coastal erosion, monitoring actions must be prepared to measure shoreline changes: to the purpose topographic methods (GPS, for example) as well as procedures for elaboration of remote-sensing data (by aircraft or satellite) can be used; the second ones are available also in archive, resulting referred to preceding periods. A further and effective support to the historical reconstruction of trends is supplied by maps, while GISs ease comparison of data that are heterogeneous because of relative acquisition techniques as well as geodetic datum and cartographic representation. In this paper contribution of satellite high resolution images is remarked: using orthorectification process different kinds of satellite high resolution images (Quickbird, Ikonos, Eros) permit to establish shoreline position with enough accuracy (1-2 m) according with the purpose of many monitoring plans. Considering a true case (Casal Velino, Province of Salerno), adopted procedure to define shorelines using Ikonos images, format GEO (11 bit, geometric resolution of 1 m x 1m for pancromatic, 4 m x 4 m for multispectral): orthorectification is realized using Rational Polynomial Functions based on Ground Control Points belonging to ortho photos (scale 1:10.000). Comparison between different shoreline collocations is carried out in GIS environment, so to provide not only measure tools, but also archive for images and textual documents that can be linked to maps and recalled, in any moment, for consulting