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Seeing Through Walls
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).'"
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.
In the future, I guess snipers will have to carry a $ 5 roll of aluminum foil, to block the multimillion dollar real time radar.
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.
"First they came for the slanderers and i said nothing."
It seems the primary application is the American military. Why do you think anyone in that camp cares about what will happen to the targets for the minute or two before they are shot from a nearby helicopter?
About the same as a heat lamp.
I wonder if it might be useful to use a sine-wave deflector to pan this signal up and down for a front view. While having an X on a top down view would be useful, having a profile could be vastly better in many situations.
Seeing behind walls? Right, military ... no way they'd ever use that in the "homeland". Oh wait, they already have trucks that do similar things with unclear health effects roaming US streets.
Odd that it was sponsored by the Department of the Air Force,
Or may-haps radar is their specialty.
A roentgen is a unit of measurement for ionizing radiation. Since these do not output any, they cannot be described as such.
those guns that shoot around corners. http://www.gizmag.com/go/2576/
On a long enough timeline. The survival rate for everyone drops to zero. Chuck Palahniuk, Fight Club, 1996
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 your own radar wave emitter that fires back one OMFG radar wave ping at it, frying it?
Lastly, make a "potato cannon" that shoots jars of Strawberry Jam and blast the array with it?
Countermeasures, we got them.
Take the Red Pill.
In a story a few days back about GPS jamming somebody mentioned how ineffective it was because of the use of radiation-guided missiles - could soldiers operating this giant radar end up in HARM's way (geddit?), and wouldn't it be possible to create a simple radiation detector that could show when such a radar is operating nearby?
"The most dangerous enemy of a better solution is an existing codebase that is just good enough." -- Eric S. Raymond
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, except that it is.
What idiot wrote that? Manipulative idiot, that's who.
Hi, I saw something like that from Czech company RETIA.
Or what about camero-tech and their Xaver 800?
It seems to have better resolution.
In English, they are called X rays (which is actually the name Röntgen gave to them).
The Tao of math: The numbers you can count are not the real numbers.
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?
Does this system run on "Windows"?
lucm, indeed.
soon we will be "flooded" with home-made pr0n movies on youtube made by some pranksters. I think it's time to buy seethruwallstube.com domain.
Cambridge Consultants demonstrated something similar a few years ago. It's called Sprint and there's a great big picture of it here.
Also allow you to see through walls.
Just sayin'
"Lost time is not found again."
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, which is a type of general search warrant, in the American Revolution. Search and arrest should be limited in scope according to specific information supplied to the issuing court, usually by a law enforcement officer, who has sworn by it.
The only people working on this are future treasonous oath breakers. The same ones who allowed the banksters to steal our monetary system, the same ones who allow electronic voting, sound weapons, fios splitters, wiretapping, and all the other full spectrum of unconstitutional bullshit.
If you think I am full of shit, explain to me why I should obligated to obey any law coming from the establishment when the establishment doesn't follow any rule of law anymore, and in fact promotes fraud, theft and murder? This is the exact reason the economy won't recover, the trust has been purged completely from the system along with peoples life savings, all at the same time the establishment cracks down on the small guy protesting, not one motherfucking bankster has gone to Ft. Leavenworth.
I am an honorably discharged veteran, I might not be the smartest fucker in the world, but I know treasonous oath breaking shit when I see it. You want this country to recover, you better start putting the oath breaking officials and their punk ass fucking foreign and corporate CEO friends and their agenda's and treaties in Ft. Leavenworth.
This is the path to darkness, death, destruction and marital law. and if it goes mainstream, you can be sure taxpayers will pay for their own incarceration and targeting.
The path to light, life, health and a constitutional republic will only be reached if the Oliver North's, the Negropontee's are flushed from the Pentagon, NSA, CIA and halls of power. The DHS will need to be de-activated as it is in 100% opposition to the US Constitution. The banks who have over leveraged must fail, their CEO's imprisoned for fraud, theft, and treason (for the Senators who swore an oath to regulate the monetary system)
If you don't care about the US Constitution, or rule of law, then frankly you aren't my friend (you are actually my sworn enemy) and I don't give a shit about your fucking life, I mean you are really only one little tiny law away from being on a hit list. Even if you think I am wrong, the fact I am wired to think it; should scare the crap out of your arrogant educated asshole. So go see your shrink, and know I know my place in the universe bitch.
It's all fun and games until someone get's their eye put out.
Would you like this technology used on your daughter, son, mother, father or wife, husband, or pet?
How about you fucking arrogant educated assholes take your "see through walls tech" to Fukushima, and help them fix the problem? No? It won't work?
This technology is useless except for enslavement of humans. All you laughing fools, giggling nerds, are the future slaves.
You lazy motherfuckers couldn't even stop electronic voting.
What about standing on the other side of the wall?
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.
"Somebody has to do something. It's just incredibly pathetic it has to be us."
--- Jerry Garcia
Until this stuff is installed on the Google Street View cars!
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
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
Oh, and I am not a groupie. I happen to actually know Greg.
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.
It's called coherent integration gain. It's done entirely digitally in a modern radar such as this and can in theory allow you to detect pretty much any signal no matter how weak [there are practical limits of course...] The whole radar they've described probably has a BOM cost of less than $200,000. The real gotcha is labor to make it work, not the material cost. That'll cost millions [probably >$10Million, you could find out if you want to dig through some defense contracts and find the value of this one...] but so did your new iPhone 4S. The difference is that your iPhone 4S is going to have millions made this not so much. If the government wanted to build 100,000 of these, the cost would probably drop to around $50,000....
Here's the idea:
1) You transmit N identical pulses of radar waveform (probably an LFM or NLFM waveform for this application)
2) They bounce off the target and return to the radar
3) You receive them. They are WAY below the noise figure (say 50db). No amount of normal filtering will get them back. You have to analyze the noise for something that isn't "noise" like....
4) You use a matched filter that has a maximum output when the input signal is exactly the LFM you originally sampled to "pulse" compress the signal
5) If you're lucky the matched filter output has gotten you 20-30 db of gain because it's looking on a single pulse basis for the exact signal of interest. That 20-30db gain DOESN'T apply to the noise, because the noise won't match the matched filter [random vs determinisitic], therefore you've gained 20-30db of SNR.
6) Now remember you transmitted N pulses. Why not look for a signal across all of those? That's the next step. For this application they'd probably use Doppler processing. Turns out that if you do this properly you get gain on the desired signal equal to the number of pulses, so if you transmit thousands you can get that remaining 20-30db needed to make the signal >15db SNR which is the usual minimum for reliable detection in thermal noise.
It's really straight forward. The challenges here are not in that part of the design. That part is easy..
The challenges are:
1) Making it realtime (Coherent processing doesn't work when targets lose coherency that happens when they move "too quickly"). This limits the number of pulses you can use to make useable system
2) Dealing with the Dynamic range between the (very) STRONG wall return and the very weak internal targets. [Very expensive ADCs and RF amplifiers can help, they've also apparently added a doppler filtering step in analog which is interesting.... But fundamentally it's a pain]
3) Target classification. The military could care less how many TV and appliances you have. Unfortunately those will show up as targets behind the wall too...
4) Making it small enough and draw a reasonable enough amount of power to be vehicle mounted
===> If you fix #1 with more output power or a larger antenna you run into this problem.....
4) Having enough resolution to actually differentiate 2 separate targets. Without going into the details this becomes problematic for short range radars like this....because you want to see things that are on order 1ft x 1ft.. Radar is much better at seeing Planes and Tanks...
The whole scheme depends on the wall reflecting in a slightly altered frequency uniformly. If you are not able to subtract the echo from the wall, you can't amplify the fainter echos from beyond the wall. Systems to thwart it would be to "roughen" the wall, interior or exterior to make the wall echo difficult to subtract. Other ways would be to have very bright echo returns that mess up and saturate the amplification of the faint echos. Also the standard stealth technologies like faceted body producing vastly different images for different elements of the array to thwart the image processing and synthesizing the scene behind the wall.
I think the resolution is poor, and is useful for hostage, military situations only. Dont have to worry about your creepy peeping tom neighbor buying this off the shelf to ogle your bath/bedroom.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
Although the truck is disguised, you can tell they're there when they put the giant piece of film up on the other side of the house.
How long till something is like this available to law enforcement . They have already gotten away with putting gps trackers on people's car in their drive ways with no judicial over-site. The privacy and legal ramifications are going to be immense. Stewbee pointed out that the majority of the plans are on developers blog, since we got camera phones people don't hesitate to violate each others privacy, imagine what will happen with this.
See page 554 in TFA. They image a guy holding a metal rod. The name of the output file in the screenshot? StarwarsKid. Yay!
A successful API design takes a mixture of software design and pedagogy.
This is not a multi-billion dollar project. With a bit of resourcefullness, you could do it yourself for under $2k in hardware, assuming you've got a good PC and a decently instrumented electronics workbench. There's no magic "millions of dollars worth of noise cancellation equipment" -- it exists in silly movies only. Either you are above or below noise floor, and even if you're below you can employ averaging to trade off bandwidth (in the sense of frame rate) for SNR improvement. Heck, they do a lot multiplexing and use a really simple data acquisition setup. If they'd get each antenna to have its own oscillator and radiate at a different frequency, they could run all the antennas at the same time, improving their SNR by quite a bit because they'd have more data to average from.
A successful API design takes a mixture of software design and pedagogy.
I think if they had a wider bandwidth ADC they could get rid of the analog Doppler filter. Eventually the oversampling in the ADC would give them back the dynamic range they need. They used about as basic of an A/D card as it gets. The BOM is way less than $200k I'm sure. The boards for the antennas probably aren't cheap due to their size, and I don't know if they are FR-4 or Rogers. They'd probably cost $2k or so on a 1 week turnaround, probably less. The RF components and cables can be scavenged off eBay if you have time, or bought from mini-circuits and similar suppliers, the latter will run another $5k tops I'd think. The A/D board is $1.2k. Mechanicals will run another $2k or so. So in a pinch you can do it for $10k in hardware less PC. If you have time to do your own board layout and circuit design, and have time to use long leadtime PCB suppliers, you can get an even better signal chain for way less money -- I think $2k of electronics per system for a run of 10 is not unimaginable. You could put the RF signal chain on a PC board and use cheaper components than having to wire everything up from enclosed modules, as they perhaps did.
They use very little bandwidth between ADC/DAC and PC, this could be easily running via Ethernet. With a proper choice of CPU they wouldn't even need an FPGA. I think that their current design's front-end digital logic would fit entirely on a Parallax Propeller attached to ADC, DAC and switches, with external Ethernet interface attached to it to stream the raw data to the PC. The Prop is too slow to do the DSP of course, but for sequencing, waveform playback and acquisition it'd work just fine. I think that a single board with ADC, CPU, Ethernet, and all of the RF signal chain could be had for $1k total in qty 1, and none of it would be very exotic at all - not a single BGA to be soldered, I'd think.
They had to trade off time for money to get this done without wasting a couple years. For proofs-of-concept it's the way to go. The design leaves a lot of room for improvement, and that's what I really like about it. If one only had enough time to play with all that! The article is detailed enough that with consulting some of the references you could replicate the whole system without too much sweat. I really like their approach to signal processing on the PC, controlling the show from Python. Very slick.
A successful API design takes a mixture of software design and pedagogy.
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 and watch for movement inside them. It could provide a good estimate of troop numbers and concentrations.
I could also see it used to hostage rescue. Dress the helicopter up like a TV crew and scan the building. You could figure out (with some guess work) the number of bad guys, number of hostages, and where everything is located.
I'm pretty confident that this technology is a CIA/DIA wet dream.
These devices have been around for thousands of years...
mfwright@batnet.com
"Hey, it looks like there's a guy with a pacemaker on the other side of this wall."
"Shit, really? That thing can see that kind of detail?!"
"No, not really."
"Well, then how can you tell he has a pacemaker?"
"He just fell down and died."
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.
Instead of Aliens or X-COM you're thinking Zelda and Harry Potter?!