The Synthetic Aperture Radar is just like the radars used on ships and airplanes. It is an active microwave sensor that transmits in microwave and detects the wave that is reflected back by objects. SAR is completely different from passive optical sensors carried by the U.S. Landsat or Japan's Marine Observation Satellite-1/1b -1 (MOS-1/1b). It enables high-resolution, high-contrast observation, and accurate determination, of topographical features, such as undulations and slopes, independently of weather conditions, even during fog or cloud cover.