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Wireless Network Modded To See Through Walls
KentuckyFC writes "The way radio signals vary in a wireless network can reveal the movement of people behind closed doors, say researchers who have developed a technique called variance-based radio tomographic imaging which processes wireless signals to peer through walls. They've tested the idea with a 34-node wireless network using the IEEE 802.15.4 wireless protocol (the personal area network protocol employed by home automation services such as ZigBee). The researchers say that such a network could be easily distributed by the police or military wanting to determine what's going on inside a building. But such a network, which uses cheap off-the-shelf components, might also be easily deployed by your neighbor or anybody else wanting to monitor movements in your home."
This sounds like a job for... Aluminum Oxide Paint!
What do you mean they cut the power? How can they cut the power, man? They're animals!
While a coat of aluminum oxide does count as a Faraday cage, I believe thickness is real issue with the protective power. Paint is only a few molecules thick (relatively) to the more traditional wire mesh. If you were going to build a new house, I think you'd be better including a brass mesh in the walls of your house.
I would think that many of the early hacker culture geeks sneaked out a lot at night - for phone phreaking, to find computer parts etc.
Investigative reporter Seymour Hersh said that the U.S. military had developed a secret new technology for use in urban warfare. He said the technology was revolutionary, equivalent to the first time tanks were deployed on the battlefield. From what I remember, there was speculation that Hersh had learned that the military could now see through walls.
You can get xbee-equipped computers (mostly with pics, avrs, basic stamps, etc) for super cheap, like three for a bill. I'm considering them for a remote monitoring and control application where wifi is overkill in some ways and inadequate in others (line of sight issues.) Current xbee modules all seem to support mesh networking, which is really the big draw to me of the protocol itself here, or at least the most readily available implementation. Being able to put out a sensor net and get a sort of meta-sense out of it would be all the more exciting. I'm sure the same thought has occurred to everyone, of course. This seems like the kind of thing that would give the [para]military types a massive hard-on given that they're already playing with the idea of gigantic numbers of drones and communications devices scattered across the battlefields of tomorrow... and our homes and cities.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
by "interrogating" this volume of space with many signals, picked up by multiple receivers, it is possible to build up a picture of the movement within it.
As I understand, the researchers used 34 receivers. You will need a whole lot of receivers. More than you might want to buy and maintain to offer you what is at best a poor resolution of moving things beyond walls.
Yes...
Actually buddies of mine weould make a late night pilgramage to Benton Harbor, MI to tresspass on the HeathKit compound to go dumpster diving. WE almost got caught about 8 times. I got enough out of their dumpsters to build my first IBM-XT and a HERO-I robot back in the late 80's.
In fact it was my buddies that started heathkit destroying things they put in the trash. One of them got greedy and started selling the crap we got out of the dumpsters.
Do not look at laser with remaining good eye.
My dad worked for Heathkit, wrote the user manual for the Hero 1. We had one in our house for a while when I was a kid. I was too young to do much with it though.
-- "Oh. This guy again."
Depending on your decade and location ... Fry's was a grocery store that was open all night...and had this large tech section.
Now it's an electronics store with the emphasis on consumer, and it's no longer open all night. But that's one place where it started around 1960. (I was just too early, and just too far away...but I sure heard about it!)
I think we've pushed this "anyone can grow up to be president" thing too far.
Whew! Imagine the fun the neighbours could have watching which room you're in: "They're watching TV, they're watching TV, they've put the the kettle on, they're watching TV...." I'm sure it will be worth the effort of setting up 32 receivers and a suitable transmitter and calibrating it - all so the neighbours can work out which room I'm in. The winter evenings are going to just fly by.....
Unicorn Setu. "Eagles may soar, but weasels don't get sucked into jet engines".
Interesting implication that, while your neighbours shouldn't be monitoring what you're doing inside your own house, it's perfectly acceptable for the police and the army to be watching you in this way.