Applications of Orbital Imaging Radar for Geologic Studies in Arid Regions: The Saharan Testimony

Abstract

The multi-frequency and multi-polarization Shuttle Imaging Radar (SIR)-C/X Synthetic Aperture Radar (SAR) data collected in 1994 aboard two flights of the Shuttle Endeavour constitute a milestone in imaging of deserts from space. The data are here used to explore the eastern Saham, including lithological and structural mapping, geomorphological studies, and mineral exploration. The SIR-C/X-SAR images in this environment are generally found to be (1) less useful for lithological mapping than orbital visible and near infrared (VNLA) images, except where rock types weather differently to produce varying roughness levels; (2) superior to orbital vm images for structural mapping in areas of subdued relief or where structures are partially covered by dry sand, as well as in tectonically active mountainous terrains; (3) superior to orbital VNIR images for mapping sugace and sub-sugace geomorphological features such as paleo-channels; and (4) useful in delineating geologic controls on mineral deposits, but inferior to orbital VNIR images for direct identification of these.