Summary of science results from spaceborne imaging radar (SIR-C/X-SAR)

SIR-C/X-SAR (Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar) is the most advanced imaging radar system to fly in Earth orbit. Carried in the cargo bay of the Space Shuttle Endeavour in April and October, 1994, SIR-C/X-SAR simultaneously records SAR data at three wavelengths (L-, C-, and X-bands; 23.5, 5.8 and 3.1 cm, respectively). In addition, the full polarimetric scattering matrix may be obtained at L- and C-band. Scientific investigations are continuing using SIR-C/X-SAR data in topics in geology, hydrology, ecology, oceanography and radar remote sensing techniques. Vegetation classification, biomass measurement, forest-floor flood imaging, snow cover distribution and wetness, and soil moisture estimation are some of the quantitative measurements that can be conducted using SIR-C/X-SAR data. In addition, a number of longer-term processes bearing on global change are being studied, including conditions of alpine glaciers, forest ecosystem health, volcanic activity, and desert processes. The October flight included acquisition of experimental repeat-pass interferometry data that have been used to generate digital elevation models and for detection of surface motions in volcanic, tectonic and glacial terrains.