SIR-C X-SAR MULTIFREQUENCY MULTIPASS INTERFEROMETRY - A NEW TOOL FOR GEOLOGICAL INTERPRETATION/

Radar remote sensing is a tool of increasing importance in the study o f volcanic sites. Synthetic aperture radar (SAR) is a high-resolution imaging tool used to survey areas which art not practical or safe to b e directly inspected. With the introduction of the across-track SAR in terferometry (IFSAR) technique, digital elevation models (DEM) can be produced. The usefulness of such interferometric products depends on t he ability to extract information that can be used for geological inte rpretation. We analyzed the shuttle imaging radar C (SIR-C)/X-SAR mult ifrequency multipass interferometry mission over Mount Etna, Sicily, a nd we performed a supervised geological interpretation of the coherenc e maps and a fractal-based analysis of the IFSAR DEMs. The first permi ts us to recognize different volcanic terrain and to distinguish betwe en vegetated and unvegetated areas, while the second allows us to vali date the IFSAR DEMs and to detect large-scale geological features. Thi s latter analysis, performed over the photogrammetric DEM, enabled us to recognize artifacts caused by digitizing and resampling. Obviously, IFSAR DEMs are not affected by these problems. As a consequence, IFSA R products are a valuable aid in geological interpretation.