New system uses low-power Wi-Fi signal to track moving humans -- even behind walls

The comic-book hero Superman uses his X-ray vision to spot bad guys lurking behind walls and other objects. Now we could all have X-ray vision, thanks to researchers at MIT's Computer Science and Artificial Intelligence Laboratory.

Researchers have long attempted to build a device capable of seeing people through walls. However, previous efforts to develop such a system have involved the use of expensive and bulky radar technology that uses a part of the electromagnetic spectrum only available to the military.

Now a system being developed by Dina Katabi, a professor in MIT's Department of Electrical Engineering and Computer Science, and her graduate student Fadel Adib, could give all of us the ability to spot people in different rooms using low-cost Wi-Fi technology. "We wanted to create a device that is low-power, portable and simple enough for anyone to use, to give people the ability to see through walls and closed doors," Katabi says.

The system, called "Wi-Vi," is based on a concept similar to radar and sonar imaging. But in contrast to radar and sonar, it transmits a low-power Wi-Fi signal and uses its reflections to track moving humans. It can do so even if the humans are in closed rooms or hiding behind a wall.