The device is tracked by aircraft radar and can be used to identify U.S. and coalition forces during combat.
The sensor works with multiple radars and aircraft, according to Sandia researcher Lars Wells. It creates synthetic radar echoes so receivers pick up the sensor signal as they would radar echoes from tanks or trucks. When the tag echoes back the radar's pulse, it modulates the signal with a digital code. The radar recognizes the digital code and places an icon on the pilot's screen to alert him. Batteries or vehicles power the tag electronics.
To keep costs down, the tags are adaptable to existing radar systems so the equipment needs no special modifications. In the future, Sandia researchers plan to put tags on every soldier.