Noisy radar sees through walls

Ohio State University engineers have invented a radar system capable of penetrating walls that is virtually undetectable, because its signal resembles random noise.

The radar could have applications in law enforcement, the military, disaster rescue and medical imaging.

Eric K. Walton, senior research scientist in Ohio State's ElectroScience Laboratory, said, "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. Radio receivers could search for this radar signal and they wouldn't find it. It also won't interfere with TV, radio, or other communication signals."

The radar scatters a very low-intensity signal across a wide range of frequencies, so a television or radio tuned to any one frequency would interpret the radar signal as a very weak form of static.

"It doesn't interfere because it has a bandwidth that is thousands of times broader than the signals it might otherwise interfere with," Walton said.