How SAR Works

A synthetic aperture radar is an active sensor transmitting and receiving microwave signals, i.e. measuring distances between the sensor and the point on the Earth's surface, where the signal is backscattered, perpendicular to the flight direction. This distance is defined as slant range which can be projected on the ground representing the ground range.

Most SAR satellites image five to ten thousand patches of ground with a single pulse. SAR satellites usually send more than a thousand pulses toward the ground each second. However, since they are moving at around 7 kilometers (4 miles) per second, each pulse is 4 to 10 meters (12 to 30 feet) apart.