SIR-C/X-SAR observations of rain storms

The spaceborne imaging radar-C, X-band synthetic aperture radar observations of rain storms are the first multipolarization and multifrequency observations of precipitation from space. In addition to numerous, often dramatic images of severe weather systems obtained by forming a synthetic aperture in the usual side-looking attitude, several data takes were performed while the radar antennas were parallel to the ground and the radar beams were pointing at nadir. These opportunities coincided with the passage of the Shuttle over Tropical Cyclone Odille in the southern Indian Ocean during the first flight and over Typhoon Seth in the western Pacific during the second flight. The resulting observations, or, more appropriately, the resulting measurements, demonstrate for the first time the capability of a spaceborne multifrequency multipolarization microwave radar system to quantify precipitation rates, to detect hydrometeor phase, and to classify rain type.