MIT Researchers Can See Through Walls Using Wi-Fi 75
itwbennett writes "MIT Professor Dina Katabi and graduate student Fadel Adib have developed a system they call Wi-Vi that uses Wi-Fi signals to visualize moving forms behind walls. How it works: 'Wi-Vi transmits two Wi-Fi signals, one of which is the inverse of the other. When one signal hits a stationary object, the other cancels it out. But because of the way the signals are encoded, they don't cancel each other out for moving objects. That makes the reflections from a moving person visible despite the wall between that person and the Wi-Vi device. Wi-Vi can translate those faint reflections into a real-time display of the person's movements.'"
its called radar (Score:5, Informative)
It's not exactly new either. The only difference here seems to be that the radar signal source is just a low power wifi AP. Yawn.
Re:Code source or it didn't happen (Score:5, Informative)
The paper http://people.csail.mit.edu/fadel/papers/wivi-paper.pdf [mit.edu]
Re:NSA Use (Score:5, Informative)
Not Wi-fi (Score:5, Informative)
I am sure they are using the same frequencies as wi-fi. But wi-fi is not just the use of a certain frequency range.
Re:its called radar (Score:5, Informative)
Standard radar cannot see through walls because the receiver is overwhelmed by the wall reflection (its ADC is saturated). According to the authors, this is a very well known challenge and is called the "Flash" effect. Wi-Vi's new nulling algorithm solves that problem, enabling for the first time narrowband RF to overcome this effect. This link explains their technique: http://people.csail.mit.edu/fadel/wivi/design.html