Use of declassified panoramic satellite imagery for change detection in an area of archaeological interest

In the framework of a multidisciplinary research carried out about the Tilmen Höyük archaeological site, in the South-East region of Turkey, and of its surrounding territory, remote sensing data are adopted for characterization of the area and of its evolution in time. In order to perform some change detection analysis, some old declassified satellite images are used coming from Corona, the first U.S. operational space photo reconnaissance program (1960-1972). The images are of panoramic type, affected by severe distortion; they were scanned at high resolution and processed using a digital photo-grammetric workstation in order to produce metric products of acceptable quality for mapping purposes. In the paper some specific problems of these cameras are presented, together with the procedures adopted for i-mage orientation and data processing. External orientation and digital triangulation were limited by the lack of well distributed and reliable ground control points, but the results are in any case of great interest as they allow the integration, on a common cartographic reference base, with current imagery (from medium to very high geometrical resolution) to perform automatic or manual procedures of comparison and change analysis.