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posted by janrinok on Wednesday August 12 2015, @05:56AM   Printer-friendly
from the shoot-out-the-lights,-unplug-the-wifi dept.

Researchers at University College London (UCL) have devised a system for detecting the Doppler shifts of ubiquitous Wi-Fi and mobile telephone signals to "see" people moving, even behind masonry walls 25 centimeters thick. The method, which could be useful in situations from hostage-takings to traffic control, won the Engineering Impact Award in the RF and Communications category at this National Instrument's NI Week 2015 meeting (which convened in Austin, Tex., 3-9 August).

Other researchers—notably Dina Katabi and Fadel Adib of MIT—have built through-wall radars in the household communication bands, but these are active radars that transmit as well as receive. The UCL technique uses only passive radiation—from Wi-Fi routers (using emissions in any of the IEEE 802.11 b, g, n, ac), ambient GSM and LTE mobile signals, and other sources—so there is nothing to betray the surveillance. The system calculates the positions of hidden target by comparing two signals: a reference channel, receiving the baseline signal from the Wi-Fi access point or other RF source, and a surveillance channel, which picks up Doppler-shifted waves reflecting from the moving subject.

Tan and company built their "high Doppler resolution passive Wi-Fi radar" on two multi-frequency, software-defined, FPGA-based transceivers (National Instruments' USRP, or Universal Software Radio Peripheral. The system compares the reference and surveillance signals, interprets the very small frequency shifts, and reveals the hidden subject's location and motion.

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Original Submission

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MIT CSAIL Unveils AI that Can Detect Human Actions through Walls and in the Dark 14 comments

Watch Out, MIT’s New AI Model Knows What You’re Doing Behind That Wall:

For better or worse, AI can now figure out what you're doing even without "seeing" you. The MIT Computer Science & AI Lab (CSAIL) has unveiled a neural network model that can detect human actions through walls or in extremely dark places.

Although automating the process of action recognition from visual data has been a computer vision research focus for some time, previous camera-based approaches — much like human eyes — could only sense visible light and were largely limited by occlusions. The MIT CSAIL researchers overcame those challenges by using radio signals in the WiFi frequencies, which can penetrate occlusions.

Their "RF-Action" AI model is an end-to-end deep neural network that recognizes human actions from wireless signals. The model uses radio frequency (RF) signals as input, generates 3D human "skeletons" as an intermediate representation, and can track and recognize actions and interactions of multiple people. The skeleton step enables the model to learn not only from RF-based datasets, but also from existing vision-based datasets.

Researchers say RF-Action is the first model to use radio signals for skeleton-based action recognition. "There are lots of potential applications regarding human behavior understanding and smart homes. For example, monitoring the elderly's abnormal behaviors such as falling down at home, monitoring whether patients take their medicine appropriately, or remote control of smart home devices by actions," says the paper's co-first author Tianhong Li.

Using RF in the "WiFi" bands. 25 hours of data was all it took (or all they collected) to train and test the AI. This article was unclear if the WiFi RF used was active, or passive although earlier reporting specifically mentioned passive.

MIT CSAIL RF Action site has a link to the paper:

This looks like an update of the story we first published in 2015, but now including AI.

Previously:


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  • (Score: 0) by Anonymous Coward on Wednesday August 12 2015, @06:33AM

    by Anonymous Coward on Wednesday August 12 2015, @06:33AM (#221593)

    Your porn watches you while you download.

  • (Score: 2) by MichaelDavidCrawford on Wednesday August 12 2015, @06:41AM

    by MichaelDavidCrawford (2339) Subscriber Badge <mdcrawford@gmail.com> on Wednesday August 12 2015, @06:41AM (#221596) Homepage Journal

    I understand they need lots of carpenters. I have all my own tools, even a contractor's table saw.

    --
    Yes I Have No Bananas. [gofundme.com]
  • (Score: -1, Offtopic) by Anonymous Coward on Wednesday August 12 2015, @06:47AM

    by Anonymous Coward on Wednesday August 12 2015, @06:47AM (#221599)

    We pay researchers to deprive us of our liberties, and they gleefully do it, because researchers are immoral whores for grant money.

    • (Score: 0) by Anonymous Coward on Wednesday August 12 2015, @07:13AM

      by Anonymous Coward on Wednesday August 12 2015, @07:13AM (#221607)

      it's just light bro

      • (Score: 0) by Anonymous Coward on Wednesday August 12 2015, @07:19AM

        by Anonymous Coward on Wednesday August 12 2015, @07:19AM (#221608)

        Well then you won't mind if I watch your daughter in the shower.

    • (Score: 2) by maxwell demon on Wednesday August 12 2015, @08:33AM

      by maxwell demon (1608) on Wednesday August 12 2015, @08:33AM (#221617) Journal

      You'd prefer if only the three letter agencies know about this possibility? This way, you at least know, too, and can use countermeasures if you care about it. I mean, it's not as if electromagnetic radiation is unstoppable.

      --
      The Tao of math: The numbers you can count are not the real numbers.
      • (Score: 1, Funny) by Anonymous Coward on Wednesday August 12 2015, @08:47AM

        by Anonymous Coward on Wednesday August 12 2015, @08:47AM (#221621)

        Lead paint, don't fail me now!

  • (Score: 0) by Anonymous Coward on Wednesday August 12 2015, @08:05AM

    by Anonymous Coward on Wednesday August 12 2015, @08:05AM (#221614)

    I want money
    I want lots of money
    In fact, I want so much money
    Give me your money, just give me money

  • (Score: 2) by inertnet on Wednesday August 12 2015, @09:32AM

    by inertnet (4071) on Wednesday August 12 2015, @09:32AM (#221629) Journal

    This system will only detect and show movement. The question is how sensitive is it? Will it show heartbeats, or can you safely move at speeds less than 1 km/h without being detected. I'm guessing that it can be tricked by moving very slowly.

    • (Score: 0) by Anonymous Coward on Wednesday August 12 2015, @11:42AM

      by Anonymous Coward on Wednesday August 12 2015, @11:42AM (#221650)

      Your neighbor might be none the wiser but your girlfriend won't be happy either...

    • (Score: 0) by Anonymous Coward on Wednesday August 12 2015, @09:45PM

      by Anonymous Coward on Wednesday August 12 2015, @09:45PM (#221941)

      Produce a randomized signal that overpowers their reference.

      If you do that it'll just come back as garbage.

      Getting ahold of variable-spectrum transmission gear capable of blanketing all those possible frequencies is non-trivial. Producing discrete, powerful, and portable jamming units for when you are in need of them even less so.

  • (Score: 2) by Aiwendil on Wednesday August 12 2015, @09:48AM

    by Aiwendil (531) on Wednesday August 12 2015, @09:48AM (#221631) Journal

    Does anyknown kmow how this kind of technology stands up against modern insulation in houses?
    Now I mean the energyeffecient houses that has metallic foil and (inadvertently) blocks cellphone signals.

    • (Score: 0) by Anonymous Coward on Wednesday August 12 2015, @03:57PM

      by Anonymous Coward on Wednesday August 12 2015, @03:57PM (#221734)

      Unless modern insulation features Faraday cage-esque wire mesh. It ain't blocking or stopping EM radiation.

      • (Score: 2) by Aiwendil on Wednesday August 12 2015, @05:34PM

        by Aiwendil (531) on Wednesday August 12 2015, @05:34PM (#221777) Journal

        The thing is just that, the newest houses here in sweden often have the problem that cellphones are effectivly blocked. It is at the point where that have to make small slits in foil of the windows in order to get a reception.

        And no, not wire mesh but actually surrounded by foil.

  • (Score: 0) by Anonymous Coward on Wednesday August 12 2015, @12:40PM

    by Anonymous Coward on Wednesday August 12 2015, @12:40PM (#221660)

    This cannot be new research, because what has been approved for public consumption is usually old news. Decades old and obsolete. They've moved on to much better methods with excellent results.

    Radar has been around a while and can be used to track movement, but I am also interested in mind reading from large distances. I know they do it because every time they do, I can sense it. If I have been thinking differently, they have police cars all over the place that day and are stopping random vehicles and checking them. I know I've not been marked for liquidation yet or I would be implanted with some electronics or already dead. I know I'm on a list somewhere and considered 'person of interest'. I've also noticed that thinking passive things does calm them down a bit.

    As for active or passive radars, all houses should be fitted with metallic sheets either on the inside or outside (and well grounded) so these harmful, unnatural, man-made radiations cannot harm us too much.

    Also, a metallic wire netting should be hung over the house to protect from above (like the netting used to protect from air raids). The satellites are watching you all the time. We don't know what those satellites can or cannot see, or if they can tell people apart. So better be careful because they are not your friends. Wear a cap at all times (when outside) that hides your face from spy satellites. And do not look up. The cap can be lined internally with tin-foil, although that makes it hot and humid inside.

    If all else fails, start living in a shipping container buried a few feet inside the earth, with two access doors (one for normal use, the other for bugging out when big brother comes looking for you) and exhaust fans, etc.

    *One issue with the summary text: A bracket has been opened, but not closed. Please close it before it destroys the world.

    • (Score: 0) by Anonymous Coward on Wednesday August 12 2015, @02:56PM

      by Anonymous Coward on Wednesday August 12 2015, @02:56PM (#221707)

      The closest to mind reading we have is FMRI that shows what parts of the brain are active.

      Determining what is is happening inside the brain from brain waves is like trying to understand what is happening inside a factory by listening to the noise while standing outside. (not sure who I stole that analogy from).

      Presumably, using a FMRI is like peaking in the windows.

      The passive radars work because our bodies partially block radio signals. Blocking those signals may mean your phone won't work anymore. Somebody else mentioned insulation: I found that the wifi signal drops 30dB upon moving outside: save for a large lobe leaking out the picture window.

      • (Score: 0) by Anonymous Coward on Wednesday August 12 2015, @04:37PM

        by Anonymous Coward on Wednesday August 12 2015, @04:37PM (#221750)

        No, the closest thing to mind reading that everyone is aware of is FMRI.

        It is not the only thing. It is possible that people are sitting in a room, connected to antennas listening for keywords people are thinking.

        Or electronics (satellites, perhaps) that scan the environment, gathering mind waves. Electronics has come a long way and antennas have improved and also noise can be filtered through software algorithms, giving big brother clear text to work with, along with the complete details of who said what. All this is entered into a database immediately for easy access. If someone enters the red zone on a graph, a team is sent to liquidate the person and destroy all evidence, while preventing everyone near that person (through mind control) to help him.

        Just because we don't know of this yet does not mean they are not already using it.