The Economist - Looking Beyond: Through-the-Wall Vision
An article in the October 15, 2009 print edition of The Economist entitled "Looking Beyond: Through-the-Wall Vision" features Xandem's innovative location technologies.
"SUPERMAN had X-ray vision, which was useful for looking through walls when rescuing heroines and collaring villains. But beyond Hollywood, the best that engineers have been able to come up with to see inside buildings are devices that use radar. Some are portable enough to be placed against an outside wall by, say, a police unit planning a raid—and sophisticated enough to show, with reasonable accuracy, the location of anyone inside. But the best models cost more than $100,000, so they are not widely deployed. Now a team led by Neal Patwari and Joey Wilson of the University of Utah has come up with a way to peer through the walls of a building using a network of little radios that cost only a few dollars each.
The ability to “see” people moving around in a building with such a cheap system has many plausible applications, and Mr Wilson has set up a company called Xandem to commercialise the idea. Besides military, police and private-security uses, radio networks might be employed to locate people trapped by fire or earthquake. More commercially, they might be used to measure what retailers call “footfall”—recording how people use stores and shopping centres. At the moment, this is done with cameras, or by triangulating the position of signals given off by mobile phones that customers are carrying. Radio tomography could be simpler, more accurate and, some might feel, less intrusive."