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Hardware Technology

Seeing Through Walls 163

Posted by Soulskill
from the life-imitates-quake dept.
An anonymous reader writes "Researchers at MIT's Lincoln Lab have developed new radar technology that provides real-time video of what's going on behind solid walls. 'The researchers’ device is an unassuming array of antenna arranged into two rows — eight receiving elements on top, 13 transmitting ones below — and some computing equipment, all mounted onto a movable cart. But it has powerful implications for military operations, especially "urban combat situations," says Gregory Charvat, technical staff at Lincoln Lab and the leader of the project.' ... each time the waves hit the wall, the concrete blocks more than 99 percent of them from passing through. And that’s only half the battle: Once the waves bounce off any targets, they must pass back through the wall to reach the radar’s receivers — and again, 99 percent don’t make it. By the time it hits the receivers, the signal is reduced to about 0.0025 percent of its original strength. But according to Charvat, signal loss from the wall is not even the main challenge. "[Signal] amplifiers are cheap," he says. What has been difficult for through-wall radar systems is achieving the speed, resolution and range necessary to be useful in real time (PDF).'"
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Seeing Through Walls

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  • by wisebabo (638845) on Wednesday October 19, 2011 @02:23AM (#37758942) Journal

    Is the amount of radiation dangerous? What about reflections? Not that it would matter in a military context but it might restrict its civilian applications.

    • by phantomfive (622387) on Wednesday October 19, 2011 @02:33AM (#37758980) Journal
      They are using Microwave, which is non-ionizing, so it is not so dangerous. You would start feeling the heat before you got any radiation damage.
      • by wagnerrp (1305589) on Wednesday October 19, 2011 @02:42AM (#37759014)
        Eh? As you said, it's non-ionizing. The heat is the radiation damage.
        • True, but not all heat is damage. You will likely feel a lot of heat before you get any real damage.
        • Eh? As you said, it's non-ionizing. The heat is the radiation damage.

          Sounds more like a feature than a bug. Remember: military applications.

      • by Misagon (1135)

        Non-ionizing means that it does not directly cause DNA damage.

        However, it has been shown in tests that microwaves of certain frequencies can have other effects on human cells other than heating them up. These effects include increasing the uptake of glucose and breaking the cell's membrane which would allow the cell to be killed by albumen in the blood.
        Not all frequencies in the microwave band are equal, though. Only some frequencies have been tested.

        • by Smallpond (221300)

          These effects include increasing the uptake of glucose...

          That's it. I'm suing the government for my obesity.

          • by treeves (963993)

            No, no, no. The CORPORATIONS are responsible for your obesity. The Government is doing their best to protect you from the evil corporations (and from yourself). Just let them do their job and you'll be fine.

      • Have you seen this [peswiki.com]?

        So much for non-ionizing radiation doesn't ionize.

        • what the hell is that non-sense? Zero point? really? As much as the guy found a trippy way to produce flame, i doubt it has ANYTHING to do with this discussion.
    • by stms (1132653) on Wednesday October 19, 2011 @02:38AM (#37758998)

      It's non-ionizing radiation so it's about as dangerous as your cellphone. This is an interesting and informative radiation chart https://www.xkcd.com/radiation/ [xkcd.com]

    • by wisebabo (638845)

      By the way, I'm sorry for the incorrect used of the word your, it should be you're as in "you are". I dislike it when people use it incorrectly so my apologies. I was in a hurry (but aren't we all?)

  • by mbone (558574) on Wednesday October 19, 2011 @02:29AM (#37758970)

    In the future, I guess snipers will have to carry a $ 5 roll of aluminum foil, to block the multimillion dollar real time radar.

    • Re:Aluminum Foil (Score:4, Insightful)

      by erice (13380) on Wednesday October 19, 2011 @02:39AM (#37759004) Homepage

      In the future, I guess snipers will have to carry a $ 5 roll of aluminum foil, to block the multimillion dollar real time radar.

      Which would shine conspicuously in the radar beam. That's where I'd shoot.

      • Re:Aluminum Foil (Score:4, Insightful)

        by mbone (558574) on Wednesday October 19, 2011 @02:50AM (#37759042)

        Crinkle it up.

      • Re:Aluminum Foil (Score:4, Interesting)

        by wagnerrp (1305589) on Wednesday October 19, 2011 @02:59AM (#37759072)
        The wall already shines conspicuously in the radar beam. They had to put an analog filter into the receiving equipment to block out the massive return they get from the wall itself so it doesn't overpower their A/D. At most, you would be able to tell "there might be something of interest behind this wall... or maybe its just a sheet of metal...".
      • by Sulphur (1548251)

        In the future, I guess snipers will have to carry a $ 5 roll of aluminum foil, to block the multimillion dollar real time radar.

        Which would shine conspicuously in the radar beam. That's where I'd shoot.

        Its a trailer park, or the enemy would make everyone put foil on their windows.

      • In the future, I guess snipers will have to carry a $ 5 roll of aluminum foil, to block the multimillion dollar real time radar.

        Which would shine conspicuously in the radar beam. That's where I'd shoot.

        Ok, so $5 foil and $3 blu-tak, so you can put it on the wall you're hiding behind.

      • What if the whole wall has a layer of aluminum sheeting inside?

    • by dintech (998802)

      Luckily the xenomorph don't have aluminum foil, so this motion tracker is still good.

    • A fridge is all you need

      http://www.youtube.com/watch?v=YNJ4c0B-s1Y [youtube.com]

      Just before the 8 minute mark

    • Re:Aluminum Foil (Score:4, Insightful)

      by Smallpond (221300) on Wednesday October 19, 2011 @09:52AM (#37761660) Homepage Journal

      Or maybe the $10 microwave detector so when they get an alarm they start shooting at the truckload of equipment outside their house.

  • Cool (Score:5, Interesting)

    by phantomfive (622387) on Wednesday October 19, 2011 @02:32AM (#37758974) Journal
    Two points:

    A) This is different than x-ray because it is using the reflection, not a film or detector on the other side of the object.

    C) The image created is not a 3D image like what you would expect if the wall were glass, instead it detects distance to objects. So what you get is like a overhead map, as if you were playing Zelda and or had the Harry Potter marauder's map. Which may be more useful in some situations.
    • by azalin (67640)
      I would assume that creating a 3 D Image from this technology is quite possible (though not trivial). In "field conditions"( the military is sure to love this gadget) it might not be necessary or feasible to have 3D. But if your planning for surveillance it might be worth the time to set up an array of these.
      Bad news for conspirationists though: Tinfoil hats will be very easy to spot and to be taken care of. Might want to invest in a radar detector though.
      • Re:Cool (Score:5, Informative)

        by wagnerrp (1305589) on Wednesday October 19, 2011 @03:13AM (#37759142)

        It was a linear phased array. It literally can't tell up from down. If you wanted to make it sense in 3-D, you would have to make the array 2-D. Stack a couple of these units, throw in a couple more GPUs for processing, re-tweak the algorithm for an additional dimension, they could probably have a 3D model working in a couple weeks.

        The issue is that 3D really doesn't get you much. With the current 2D system, you can tell where someone is in a room, but its not like you can see any identifying features. All 3D would get you is a very rough estimate of height.

    • Two points:

      A) This is different than x-ray because it is using the reflection, not a film or detector on the other side of the object.

      C) The image created is not a 3D image like what you would expect if the wall were glass, instead it detects distance to objects. So what you get is like a overhead map, as if you were playing Zelda and or had the Harry Potter marauder's map. Which may be more useful in some situations.

      B) Somebody uses a Dvorak keyboard!

  • those guns that shoot around corners. http://www.gizmag.com/go/2576/ [gizmag.com]
    • by SomePgmr (2021234)
      Meh, CornerShot is old. Like, 2003 old, and hasn't caught on anywhere that I've seen. Though I did see one used on a game show recently.
  • by vaene (1981644) on Wednesday October 19, 2011 @03:01AM (#37759080)
    Who wants to play the special mission where you are the guy pushing around the cart with all the antennas sticking out of it?
  • So, will my microwave oven jam this thing up? Cook lots of hot microwaved burritos and keep Big Brother from watching you? When will I get my glasses that let me see through clothes, see my own bones, etc? Remember those? They were on the opposite side of Sea Monkeys.

    Also, time to bring the radar detector inside so you know when to step out and unload some buckshot? Or just wire your radar detector into your homemade rocket and "nuke it" from a couple of blocks over?

    Stuff the walls with tinfoil? Or build yo

  • Meh, Counter Strike bots have been doing this for years.
  • "what's going on behind solid walls."

    Of course, what is going on behind liquid walls will remain a mystery.

    "signal loss from the wall is not even the main challenge. '[Signal] amplifiers are cheap,' he says. What has been difficult for through-wall radar systems is achieving the speed, resolution and range necessary to be useful in real time"

    Of course, the main problem in achieving the "speed, resolution and range" is that you lose 99% of the signal, twice.

    In other words, signal loss is not the main problem

  • by jklovanc (1603149) on Wednesday October 19, 2011 @03:45AM (#37759276)

    So it is good at locating people moving behind a wall. Can you tell if the person is armed?

    If you also display stationary objects, is the blob in the corner a person or a filing cabinet?

    Look at the size of the thing. I do not see a tactical unit trundling something that big so that they can see 20m through a wall. I am not sure but if you decrease the size of the antennas your power and resolution goes down. Also how much power does the radar and computers use? How long would it last on batteries?

    • by satuon (1822492)

      Even if they weren't armed, you could always place a pistol in their hands post-factum.

    • by gknoy (899301)

      It seems like something that could be extremely useful for scouting a room in a hostage rescue situation: you know the bad guys are in this room, but you want more info on where. Of course, they could probably use a fiber optic camera for that in most cases.

      • by jklovanc (1603149)

        The only issue with a fibre optic camera is that it needs a hole to look through. It is quite possible that the drilling through the concrete wall could be heard.

  • Does this system run on "Windows"?

  • by Anonymous Coward

    This technology is unconstitutional. I have zero faith the arrogant slashdot crowd to actually comprehend it until it's too late. It's all fun and games until someone's eye get's put out.

    The Fourth Amendment (Amendment IV) to the United States Constitution is the part of the Bill of Rights which guards against unreasonable searches and seizures, along with requiring any warrant to be judicially sanctioned and supported by probable cause. It was adopted as a response to the abuse of the writ of assistance,

    • Thank you, sir. You're encouraging me to join the "OWS" groups and help them avoid being co-opted.

      Mod. Parent. UP.

    • by tibit (1762298)

      While some of your objections against such technology's possible uses are understandable, the technology is not to blame. What we already have: miniature cameras and insane U.S. building standards will let anyone spy on anyone else anyway, right now, with much simpler tech.

      For non-U.S. dwellers: a typical recent U.S. single-family residential building's wall consists of, going inside out: paint, drywall, plastic vapor block, vertical wood studs with fiberglass insulation between them, foam board "sheeting",

      • by gknoy (899301)

        the technology is not to blame

        So true.

        Unconstitutional searches can be done with nothing more than one's eyes, or by breaking in a door and searching using a sledgehammer and searching. It's not the technology that makes a search bad, it's the people that are doing it and their willingness to disregard the fourth amendment.

    • The 2nd Amendment already provides the means to confront most of the BS in your "Wah Wah Wah..." rant. The idea of technology being unconstitutional is just as stupid as those claiming opensource software is a human right. Firearm technology developed 200+ years ago that can infringe on your rights just as effectively as technology capable of looking through walls. It's not the technology it's the people using the technology. Your argument boils down to stopping all technological advances just because someo
    • by dkleinsc (563838)

      This is the path to darkness, death, destruction and marital law.

      As the son of a lawyer who handled a lot of divorce work, I have to say that was one of the funniest typos I've encountered in a long time.

      You're mostly right about the rest of your post though. The thing I want to point out, though, is that many of the civilian population are justifiably afraid that if they do something about what's going on, they'll lose any chance of working, which means they'll (soon, once the 2012 election is done) lose their ability to feed, clothe, and house themselves and their kids

  • But it has powerful implications for military operations, especially "urban combat situations,"

    Oh, yes, that's where it will be used. No way they would EVER use it against their own people.

    • by jklovanc (1603149)

      Like IR cameras, it would soon be banned from doing illegal searches.

      • Like IR cameras, it would soon be banned from doing illegal searches.

        Those aren't banned at all. They just can't use the results of car-based cameras as evidence in court. They still use the ones in helicopters to conduct raids, and I'm sure they use them in plenty of other circumstances, too.

        Of course, all they need these days is a grant from DHS and a claim that they are looking for "terrorists", and they can do whatever they want. No court even needed, once they ship you off to Gitmo.

      • Like IR cameras, it would soon be banned from doing illegal searches.

        Thought I'd follow up with this little tidbit, from a story about the SCOTUS case you're referring to [go.com]:

        Detective Larry Wilson of the Plano, Texas, police force, said it has been common for police to use thermal imaging on houses without first obtaining a warrant, and that will change.

        But he says the police in his department and others he's trained around the country have been instructed not to use the devices without having first obtained probable cause through other means. So he says the ruling should not

        • by jklovanc (1603149)

          There is a huge difference between an illegal warrantless search, which I was referring to, and a search sanctioned by a warrant. With a warrant the police have a judge's permission to look into a building. Whether it is done by radar, IR or eyeballs makes no difference. So no, the police are not going to be driving down the street scanning random people in their houses.

          As a ERT tool this is a good one. It could be used before a search warrant is executed to locate all people in the house and possibly decre

          • When executing a warrant all reasonable tools should be used.

            The police state in the US is WAY beyond using anything resembling that kind of restraint. They are now accepting collateral deaths of police and innocent civilians as justified to combat recreational drug use. Expansion of those powers in the name of fighting "lone wolf terrorists" is a frightening prospect.

            • by jklovanc (1603149)

              Interesting how you neglect to mention the deaths of police and innocent civilians caused by the purveyors of recreational drugs. Some of the deaths of innocent civilians occur when two purveyors of recreational drugs fight over the same territory. There are many documented cases of drug gangs having and carrying automatic weapons and assault rifles. So when the police have to deal with these gangs that do so using heavily armed, highly trained units. If you don't want to get shot when an SRU shows up then

              • Interesting how you neglect to mention the deaths of police and innocent civilians caused by the purveyors of recreational drugs.

                Because it's irrelevant to the discussion. Those are not actions sanctioned by the state (although the state's very prohibitionist stance on recreational drugs has certainly precipitated the environment in which black marketeers become violently defensive of their activities).

                So when the police have to deal with these gangs that do so using heavily armed, highly trained units.

                I won't excuse the actions of the state when they have created the very atmosphere of violence they are claiming to combat.

                If you don't want to get shot when an SRU shows up then don't pull a gun.

                That doesn't help most of the time [cato.org], and especially when you aren't given an opportunity to identify the group t

  • Until this stuff is installed on the Google Street View cars!
  • by stewbee (1019450) on Wednesday October 19, 2011 @08:35AM (#37760820)
    The person who designed the radar was posted before, but this was about his PhD project. Here is the link and you too can build your own SAR (as long as you can read his cat scratch of notes on his blog)

    http://hardware.slashdot.org/story/10/06/18/1350259/diy-synthetic-aperture-radar [slashdot.org]

    Also on his blog, you will see similarities to what he developed for his PhD and what he is working on now.

    http://www.mit.edu/~gr20603/Dr.%20Gregory%20L.%20Charvat%20Projects/Synthetic%20Aperture%20Radar%20(SAR).html [mit.edu]

    Oh, and I am not a groupie. I happen to actually know Greg.
    • Since you seem to know something about it, maybe you could answer this: why is this suddenly such a big deal? I thought the original article was a big deal because he'd made synthetic aperture radar out of stuff he picked up on ebay -- it was a really amazing DIY hack, in other words. But militaries have had SAR for decades, right? So how is what he's doing different than what's been available for many years? Obviously it is, because this is making news all over the place, but I feel like I'm missing so

      • by stewbee (1019450)
        While I somewhat agree with you, I haven't followed it too closely. However, I believe that Greg mentions what some limitations are of SAR and that would be the real time processing to make it viable for field use. I think how things were done before was that you had several radar images taken by a single radar that had physically been moved at some small increment apart. Now here, he has several antennas so that all he as to do is electronically switch between antennas in his array to capture the images. T
  • There was a similar device in a sci-fi novel I read some decades ago, I forget the name but it might possibly have been California Dreamtime. Anyway, an assassin (bad guy) equipped with super advanced milspec tools is stalking someone and has a sonar device on his belt and contact lens displays. I wonder if sonar, or perhaps a laser scanner (as typically available for robots, but at microwave or terahertz frequencies) wouldn't be better than radar.

  • The best I could make out from the description was that it is basically radar. But the echos have small difference in frequency compared to the original radiated signal. They use a band-pass filter, must be a very good one, to filter out the echo from the wall, and then amplify the faint echos from objects behind the wall. The array of radar would each get a "2D" view, and it is synthesized into a three D image using image processing. Sort of like X-Ray tomography in the image reconstruction process.

    The w

    • by tibit (1762298)

      There are no frequency differences from the echos from stationary objects. They use beamforming/SAR techniques to get a stationary antenna to form a 2D image in downrange/crossrange coordinates (far/near vs sideways). There's no imaging along the top-bottom direction, although that's not a big issue: all they'd need is to replicate their linear antenna into a 2D antenna. The echo from the wall is still there, but they simply subtract a reference radar image from current image. If you stand very still, the r

    • by tibit (1762298)

      Hmm, I've re-read the article and it does seem like they use a filter to get rid of some of the wall echoes. They say it's their way of doing range gate, and I only imagine it's because the transmitted pulse is frequency-chirped. The earlier reflections will have different frequency than the later ones, so they essentially shift a time domain problem into frequency domain by sending out a time-dependent frequency signal.

  • See page 554 in TFA [mit.edu]. They image a guy holding a metal rod. The name of the output file in the screenshot? StarwarsKid. Yay!

  • I don't know why most people assume that this will be attached to a truck, or moved my hand. If I were the military first thing I would want to use it for is helicopter surveillance. You would have to make it more powerful to work at reasonable elevation, and would probably want to widen the field of view. Not easy tasks I'm sure.

    But suppose that you could fly around in a helicopter higher and faster than "likely to get shot down by rifle fire" speed/range or at night. You could scan large swaths of houses

  • These devices have been around for thousands of years...

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