Skip to comments.New system uses low-power Wi-Fi signal to track moving humans — even behind walls
Posted on 06/29/2013 5:17:05 PM PDT by BenLurkin
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.
As a Wi-Fi signal is transmitted at a wall, a portion of the signal penetrates through it, reflecting off any humans on the other side. However, only a tiny fraction of the signal makes it through to the other room, with the rest being reflected by the wall, or by other objects. So we had to come up with a technology that could cancel out all these other reflections, and keep only those from the moving human body, Katabi says.
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 antenna 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.
(Excerpt) Read more at web.mit.edu ...
I wonder if this will be just as illegal as using FLEER to look for people growing pot in homes?
Doesn’t matter. A law for its use will be passed, signed and upheld by kangaroo courts.
or we’ll fimd out this article is really just new to the public, and that’s it’salready in use.
Well the courts ruled that police who raided a pot grower on the evidence of the heat signature picked up by FLEER through the case out for illegal violation of fourth amendment rights.
FLIR. Fleer makes bubble gum.
This concept is valid, but at 2 or 5 ghz wifi frequencies the resolution will be poor compared with UWB, which has been used for thru-wall imaging for several years.
I assume a sniper could ‘see’ his target through the wall then blast him with a 50 caliber.
If King George had this kind of technology and the Patriots didn’t, we’d still be part of England.
Don’t you dare try this on the home of an LEO or an elected official or an employee of the NSA, though.
“If King George had this kind of technology and the Patriots didnt, wed still be part of England.”
No, I think the piece of real estate known as the 13 colonies might still be a part of England, but all the real patriots would be dead.
Think then, think now. BO and the rest of the stink in DC would like us who are the real patriots also to be dead.
"..I could use this"
If the Patriots had this kind of technology, they wouldn’t have resigned Hernandez for 40 million.
“resigned” should be “re-signed”
A Ham operator with a Function Generator could defeat this method. (I think)
Thanks, my way would have been pretty sticky!
Here’s a video showing UWB thru-wall imaging in operation:
One of Big Brother’s new toys.
LOL...but the Patriots do have this kind of technology...it’s called Tim Tebow! :) ... a wide receiver who can think like a quarterback ought to be able to catch 9 out of 10 thrown his way...built in tracking...and he knows with whom he should discuss it all...he has the knee for it...
and the Warriors of the WoD will herald the shredding of the 4th even more.
Uses technology similar to the old see thru walls glasses,, they always fogged up. :-)
I was roundly laughed at here for suggesting that, as a joke, when the police first started looking at Hernandez. Since then, I've seen some articles on the sports blogs suggesting the very same thing--Tebow is big, he's strong, he did the full combine and scored higher than most tight ends, etc. I don't think that will happen, though, outside of some trick plays.