Stealth radar sees through trees, walls--undetected.(NEWS WATCH)(Ohio State University )(Brief article)

Scientific Computing, July, 2006

Ohio State University engineers have invented a radar system that is virtually undetectable because its signal resembles random noise. The radar could have applications in law enforcement, the military and disaster rescue. Says senior research scientist Eric Walton, "Almost all radio receivers in the world are designed to eliminate random noise, so that they can clearly receive the signal they're looking for." The radar scatters a very low-intensity signal across a wide range of frequencies, so a TV or radio tuned to any one frequency would interpret the radar signal as a very weak form of static.

A receiver could not detect the signal unless it knew exactly what random pattern to look for.