Angkor Thom, just north of the temple of Angkor Wat, is viewable in this high-resolution Topsar/Airsar radar image. The radar can very accurately determine the height of every five square meters (54 square feet) of landscape. Different colors in the image indicate slight variations in topographic relief, which influence the brightness of the radar signal. Such elevation changes are often indicative of archaeological development.
Image credit: PNAS, NASA/JPL and University of Sydney