Superman-like X-ray vision now a reality through Wi-Fi technology

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Washington: We could all now have Superman-like 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 said.
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.
To do this, the system uses two transmit antennas and a single receiver.
The two antennas transmit almost identical signals, except that the signal from the second receiver is the inverse of the first.
As a result, the two signals interfere with each other in such a way as to cancel each other out.
Since any static objects that the signals hit - including the wall - create identical reflections, they too are cancelled out by this nulling effect.
In this way, only those reflections that change between the two signals, such as those from a moving object, arrive back at the receiver, Adib said.