Comparing radar images to data collected by teams of people on the ground as well as aircraft and ships using simultaneous measurements of vegetation, soil moisture, sea state, snow and weather conditions during each flight.

The Radar-C system was built and operated by NASA's Jet Propulsion Laboratory (JPL).

The mission was a joint work of NASA with the German and Italian space agencies.

[4] The SIR mission revealed hidden river channels in the Sahara Desert indicating significant climate change in the past.

[2] Radar also found temples in Angkor,[6][7] and ancient segments of China's Great Wall.