Geological mapping in the zone of Chotts, Tunisia, using ALOS sensors

The three sensors onboard the Advanced Land Observing Satellite (ALOS) are the Phased Array L-band Synthetic Aperture Radar (PALSAR), the Panchromatic Remote-Sensing Instrument for Stereo Mapping (PRISM), and the Advanced Visible and Near-Infrared Radiometer type 2 (AVNIR-2). Each of them has been evaluated for the geological mapping of the Zone of Chotts, Tunisia. Both the endoreic basins and the surrounding ranges have been studied. The 10m-resolution AVNIR-2 sensor is a good trade-off for geological mapping. The 2.5m-resolution PRISM sensor with its stereoscopic capability is very useful for the detailed study of sedimentary layers. Copolarized radar data are relevant for the study of the flat itself but the C-band is more accurate for sensing the roughness of the finer sediments (sand veneers, evaporites, etc.). The HV polarization is suitable for identifying the presence of halophytic plants that fringe the upper part of the flat.