SAR Satellites and Sensors

The SAR makes use of the radar principle to form an image by utilising the time delay of the backscattered signals. SAR sensors send out short pulses of microwave energy and then record the strength and origin of the returning reflections.

As the line of sight direction changes along the radar platform trajectory, a synthetic aperture is produced by signal processing that has the effect of broadening the antenna. The possible azimuth resolution of a SAR is approximately equal to one-half the length of the actual (real) antenna and does not depend on platform altitude (distance). In order to map the ground surface the radar beam is directed to the side of the platform trajectory.