Evaluation of the Shuttle Imaging Radar (SIR-C/X-SAR) data for mapping paleo-drainage systems in the Kingdom of Saudi Arabia

NASA launched the Space Radar Laboratory (SRL) on the two space shuttle missions of “Endeavor” in April and October of 1995. The purpose of these missions was to assess the utility of Shuttle Imaging Radar (SIR-C/X-SAR) for applications in geology, hydrology, agriculture, forestry, desert studies, oceanography and subsurface mapping. The data coverage for the Kingdom of Saudi Arabia from the two missions was processed and analyzed for their ability to show surface and subsurface expressions of drainage channels, or wadis. The processing of the images included removal of speckle, merging of radar with optical Landsat imagery, and color compositing for optimum contrast. The evaluation was carried out at two sites in the Nafud Al-Mazhur and in the southern margin of the Rub’al Khali. Results indicate that radar imagery has the potential to detect old river beds (wadis) buried under a thin cover of sand. It is therefore anticipated that the radar data will be useful in enhancing the present understanding of the hydrogeology and paleo-climate of the Arabian Peninsula.