Think you guys are talking Side Looking Airborne Radar and synthetic apertures . If it is, the rest of you, its radar usually mounted on the under side of an air craft that paints a picture of the whats underneath. Handy for picking out things of high military value on the ground. Its a lot like the side scans only using Radar.
One of the most recent uses of this was from the shuttle as it was used to map a large part of the earth.
WarrenMN