A U.S. Department of Defense program to develop a foliage penetrating radar, that can detect people, vehicles and structures underneath trees and other foliage, recently completed twenty successful flight tests, which included over 50 hours in the air. The FORESTER (Foliage Penetration Reconnaissance, Surveillance, Tracking and Engagement Radar) system was carried on a A160T helicopter UAV. Foliage penetrating radars were developed from ground penetrating radars, and use powerful computers and software to sort out what is underneath the foliage. This is a major military advantage, as ground troops have traditionally been able to hide from aerial reconnaissance by going into forests.
The A160T is a small helicopter, able to fly under remote control or under its own pre-programmed control. The two ton vehicle has a top speed of 255 kilometers an hour, and was originally designed to operate for up to 18 hours carrying a payload of 300 pounds, but it can carry a ton of cargo for several hours. Maximum altitude was to be about 30,000 feet, and its advanced flight controls were to be capable of keeping it airborne in weather that would ground manned helicopters.
The advantage of a helicopter UAV carrying FORESTER, is that this allows the radar to concentrate on a bit of jungle, at close range, long enough for the radar to gather enough data for the pattern analysis software to figure out what's going on down on the ground.