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DIY Synthetic Aperture Radar 118

Posted by kdawson
from the be-the-first-on-your-block dept.
An anonymous reader lets us know about a DIY synthetic aperture radar built for $240 in parts (give or take). Here's PDF slideware from the Ph.D. student's research. "Using a discarded garage door opener, an old cordless drill, and a collection of surplus microwave parts, a high resolution X-band linear rail synthetic aperture radar (SAR) imaging system was developed for approximately $240 material cost. Entry into the field of radar cross section measurements or SAR algorithm development is often difficult due to the cost of high-end precision pulsed IF or other precision radar test instruments."
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DIY Synthetic Aperture Radar

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  • Crooks (Score:5, Insightful)

    by biryokumaru (822262) <biryokumaru@gmail.com> on Friday June 18, 2010 @10:24AM (#32612744)

    I'm part of a team who did something similar (We're presenting it at IEEE MWSCAS, it's much less cool than this, though). We built several thousands of dollars worth of test equipment using cheap junk and came out with stuff that was just as good. DIY folks have been doing this for decades, of course, but PhD students are now starting to publish these things. This is a big deal, and means that legitimate researchers can pick up this work and very easily enter a field of research their institutions may have previously been unable to fund. Our school has always just enlisted students to design and build all of our test equipment, but still. This is good.

    I didn't RTFA, but I certainly hope they've open-sourced their backend interface software and hardware designs as well. Of course, if you're disassembling a microwave, you can hardly patent the technology. Closing off access to your work kind of defeats the purpose in science, though.

    • Re: (Score:3, Informative)

      by rrhal (88665)
      TFA is and abstract to a paper and some links. He's generating his synthetic aperture by moving the radar head on a rail (modified garage door opener style). I was curious how he went about getting the necessary motion.
    • Re: (Score:3, Insightful)

      by kalirion (728907)

      Yup, definitely sounds like something crooks would do.

      Wait, what am I missing?

      • Re: (Score:3, Insightful)

        by biryokumaru (822262)
        Haha, sorry, I never got to the point on that. The crooks are the people who charge $10,000 for something you can build in your garage for $50.
        • Re:Crooks (Score:5, Insightful)

          by jschottm (317343) on Friday June 18, 2010 @12:39PM (#32614374)

          What's your point? The grocery store wants to sell me a red pepper for $2 that I could grow for a few cents. That doesn't make them crooks, it's just the nature of capitalism and value add. Raising your own produce is only cheap if you know how to do it, have the space to do it, and are willing to put in the time to do so. And if your time is free. The free market also provides other options - I can get them cheaper at the farmers' market, but only during certain portions of the year and only if I'm willing to shop at specific times. It's all about tradeoffs and what people are willing to pay for.

          The crooks are the people who charge $10,000 for something you can build in your garage for $50.

          Most people can't build anything of the kind for any amount of money. How many people do you think know how to solder? The reason why this guy was able to build this for $240 is because he has a $150,000+ education, is far above average, and has access to the tools needed to make this.

          Are you proposing that you get paid minimum wage once you graduate because students are willing to work for free or cheap on projects? Or do you expect to get paid enough to live above a student quality lifestyle, pay back student loans, support a family, etc.? Are you advocating for communism?

          Does your $50 test equipment have a warranty? Support? Certification? Documentation? Insurance covering damages if it should short out and burn down the lab? Can a replacement be overnighted from the factory if need be? Are you factoring in the fact that your university is subsidized by research grants, donors, and possibly the government (if it's a public school) which distorts true costs? Are your scavenged parts going to be reliable? Are you providing health insurance for the people building the gear? Unemployment insurance? FICA? Paying rent on the facility? Allowing for a middle salesman who'll be vital to getting your product into customers' hands?

          The basic fact of capitalism is that you price your product and/or service as high as you think the market will pay. Unless there's a monopoly, either you've priced yourself appropriately or someone will undercut you and you'll have to lower your prices or go out of business. There's nothing wrong with aiming for the high end of a market. If you can double your prices and still get half of your business, you're doing less work for the same money. Of course, your customers might not be very loyal as a result.

          If you think that the test equipment is overpriced, once you graduate, find some investors and start your own company with better pricing. But I'd recommend taking a few business classes first. Even if you got your parts, tools, shipping, and rent for free (and paid no taxes), you'd still have to make and sell 4 or 5 pieces of test equipment at $50/each every week just to pay yourself minimum wage.

          • Well, capitalism is nice for paying the rent and all, but it's still contrary to the nature of the pursuit of knowledge. I'm just saying that the spirit of open source is spreading in a meaningful way into more facets of academia than software, and that's a good thing.

            Additionally, I'm not starting a business and selling this crap for $50. I'm making it so that anyone who wants this equipment can easily assign some undergrad to toss it together over a weekend. I don't see why it should cost an arm and a leg

          • You go on and on about capitalism and the free market but the basic fact of the matter is that there are so few people demanding these devices and so few companies selling them that the rules theorised for grain and bullion markets simply do not apply. There is enormous price gouring and manipulation going on by companies who have cornered these so called "markets", which are in reality simply landlord/tenant relationships without the corresponding protections.

            These devices cost less to make than a DVD play

            • by CommieLib (468883)
              So, if these companies are making obscene profits, why are said profits not drawing competitors in to bid down the price? Like the guy said, if it's such a sure thing, then start a business doing it and cash in, dude! Chances are, and I think you realize this in your heart of hearts, that putting together a business to do this is a lot more complicated than bitching about it on Slashdot.
            • by sumdumass (711423)

              The same "rules theorised for grain and bullion markets" still apply. The variables are just different though. In grain, you get a lot for a little work as nature provides most of the investment. With these devices, you get little for a lot of work (comparatively). Gain then has to be stored somewhere and processed special in order to remain usable for it's intended purpose. In both, your markup has to be income that lasts a good portion of the year when grain can't be harvested-sold. If you spend income or

            • by shiftless (410350)

              These devices cost less to make than a DVD player, yet are being sold for a thousand times the price.

              Except that's not the case at all. The commercial radar you buy for your aircraft, your naval destroyer, etc is not some cheap POS garage door opener bought out of a yard sale and hacked up by some geek. It goes without saying that the design for a commercial radar is completely different, the construction is different, everything is different--and much more complex--than some crap you might hack together fo

          • by shiftless (410350)

            Does your $50 test equipment have a warranty? Support? Certification? Documentation? Insurance covering damages if it should short out and burn down the lab? Can a replacement be overnighted from the factory if need be? Are you factoring in the fact that your university is subsidized by research grants, donors, and possibly the government (if it's a public school) which distorts true costs? Are your scavenged parts going to be reliable? Are you providing health insurance for the people building the gear? Un

        • by saider (177166)

          People pay $10k for a $50 widget because of the time needed to certify that the $50 dollar item was built correctly and works as intended. You can try to sell me the $50 item, but if my manufacturing process needs things like a calibration certificate traceable to a NIST standard, then I'm going to buy the $10k item, deliver on time and charge the customer. I don't have time to certify that the device operates as intended (which requires time and a whole other set of equipment). Customers are much more inte

          • I'm talking about universities, not industry. This is America, our academic institutions have no standards.
          • by hjf (703092)

            Um, no, people pay $10k because companies ask for that. And companies ask for that not because of the certification crap, but because it's not mass produced. Any microprocessor today has more R&D, testing, certification and all you can name, but it doesn't sell for $10k. On the other hand, test instruments (for example) don't have such a huge market (like a microwave frequency generator, or a 50GHz scope, or even a 300A regulated power suply). So when you divide all the cost (especially human - those sc

    • DIY is great - but is it worth a Ph.D.? I don't think so. I hope the guy did something more fundamental than the summary might lead you to believe.
      • Re:DIY == Ph.D.? (Score:4, Insightful)

        by Bigjeff5 (1143585) on Friday June 18, 2010 @12:36PM (#32614314)

        I would think most of the great Ph.D.'s would be DIY, else what's the point? Your thesis is supposed to be original research, and serious research at that, so I don't see how coming up with a way of building extremely expensive technology at a tiny fraction of the cost in your garage is anything but exactly what a Ph.D. thesis is all about.

        It's not a book report or high school research paper, you know.

        • Haha, book report... no, people don't get degrees from book reports, they get them for doing a "literature review!"
        • Re: (Score:3, Insightful)

          That's a reasonable response. I think you would find many PH.D.'s - at least in the sciences, I won't venture to comment on the arts or fine arts - are entirely theoretical which I hope you would agree are not DIY - at least not DIY in the colloquial sense as I understand it. On your assertion that there is no point if it isn't DIY let me say that if it had been a thesis E=MC**2 would not be DIY, but I hope you agree there would be a point to it.

          building extremely expensive technology at a tiny fraction of

    • IEEE MWSCAS

      www.bitboost.com/pawsense/

      Glad I could help. :)

    • We built several thousands of dollars worth of test equipment using cheap junk and came out with stuff that was just as good.

      And of course, you calibrated it against known standards so you know that for certain. (Calibration is what makes the difference between cheap junk and useful equipment.)

      DIY folks have been doing this for decades, of course, but PhD students are now starting to publish these things. This is a big deal

      Yes, it's a big deal. DIY grad students, PhD candidates, etc... have been c

      • Re: (Score:3, Insightful)

        by biryokumaru (822262)

        It represents the distinction between every student having to reinvent the wheel for every project, and future students being able to build more complex testing equipment by combining together others' works.

        Saying this is bad can be liken to decrying scientists for standing on the shoulders of giants.

  • by Philip K Dickhead (906971) <folderol@fancypants.org> on Friday June 18, 2010 @10:29AM (#32612786) Journal

    This could fall into the hands of terrorists.

    Citizens are consumers. We are passing Intellectual Property laws, to ensure that they remain so, and do not make the mistake of becoming producers.

    This man's brilliance sets another difficult example and precedent, which will be hard to contain or dismiss! I suggest a patent law-suit against him, and a criminal charges based on illegal production of weaponizable technology.

  • Wave Motion Gun? (Score:2, Interesting)

    by Gothmolly (148874)

    Can you mount this on your car? Maybe torch the guy who cut you off in traffic?

    • by jbezorg (1263978)

      Of course!

      Though... there is a problem of getting them to stay on the rotating turntable.

    • Sort of like this [wikipedia.org]? If you can make one smaller and for less money than Raytheon can, the military will want to by lots of 'em from you. Once you see the paperwork the military wants you to fill out in order to sell them anything, you'll want to charge them as much as Raytheon does, though.
  • by seniorcoder (586717) on Friday June 18, 2010 @10:33AM (#32612848)
    A strange thing happened shortly after this equipment was assembled and tested. I noticed that whenever I got angry, my skin would turn green and I would tear off my clothes.
    • No matter how much we tweaked it, we couldn't get the undergrad coeds to do the second part without the first one. Oh well, I guess we can live with Orion slave girls.
    • Re: (Score:3, Funny)

      by capt.Hij (318203)

      After years of monitoring postings across the net I have finally found you. I knew the internet would be your weakness, and you would slip up. Now, I will hunt down your ip address and finally bring some small measure of justice to this world.

      --Thunderbolt Ross

    • A strange thing happened shortly after this equipment was assembled and tested. I noticed that whenever I got angry, my skin would turn green and I would tear off my clothes.

      Which part did you find strange?

  • Old? (Score:2, Informative)

    by b00fhead (669286)

    This seems to be from 2006/7...

  • A lot more than 240 (Score:5, Informative)

    by apepooooop (777854) on Friday June 18, 2010 @10:39AM (#32612926)
    "A National Instruments PCI-6014 data acquisition card triggers radar pulses and digitizes the video data". http://sine.ni.com/nips/cds/view/p/lang/en/nid/11442 [ni.com] With a $700 (not counting accessories) data acquisition card.
    • by chill (34294) on Friday June 18, 2010 @10:59AM (#32613164) Journal

      $150 to $450 on EBay, but still your point is valid.

      • $150 to $450 on EBay, but still your point is valid.

        Even if it is $700, his point still doesn't invalidate the researcher's point: technology which the conventional wisdom holds is only available to organizations with large budgets is actually available at what are essentially middle-class consumer prices.

        The point isn't that you can do it for precisely $500 or $700 or $1200 or $2000 or $5000. The point is if you know someone with reasonable engineering skills and you can raise a few thousand bucks, you can

        • by temojen (678985)
          Just like the "homebuilt cruise missile" (basically a V1 with GPS guidance) from New Zeland a few years ago.
        • by rdnetto (955205)

          The point is if you know someone with reasonable engineering skills and you can raise a few thousand bucks, you can build this stuff.

          If nothing else, this has significant ramifications for asymmetric military conflicts...

          Something tells me that those "asymmetric military conflicts" are such because they don't have anyone with reasonable engineering skills - what they do have is people who can follow instructions to make stuff, and people who can find instructions for said stuff.

    • Re: (Score:3, Informative)

      by Alex Belits (437) *

      Not counting computer, Windows, Labview and Matlab.

      If anything, someone concerned with the cost would try to exclude the last two, as they alone make it more expensive than "high-cost" radars.

      • by MoonBuggy (611105)

        OTOH, someone in a university environment is quite likely to be covered by site licenses already on those two, thus making the effective cost zero.

        • Re: (Score:3, Interesting)

          by Alex Belits (437) *

          Someone in a university usually can just get a radar from the university. That doesn't mean, he can proclaim that he invented a zero-cost radar.

      • by rdnetto (955205)

        Not counting computer, Windows, Labview and Matlab.

        If anything, someone concerned with the cost would try to exclude the last two, as they alone make it more expensive than "high-cost" radars.

        Replace Windows with Linux, and Matlab with Octave. There's probably a FOSS alternative for Labview as well. It's fairly safe to say that most people have access to a computer (presumably also how they got access to these instructions), especially since he didn't specify what kind of hardware you'd need to run this - an decade old PC would probably be more than enough.

        • by Alex Belits (437) *

          True, however this is what the author of this "low-cost radar" did not do, and apparently didn't even consider doing.

    • Anyone with a decent sound card in their PC already has a better DAQ rig.

  • Am I the only one who read "GOATSE with pushpins" and thought that it sounds a lot more painful than the regular goatse?
  • but I did not feel like getting a headache like I always do reading webpages with white text on a black background.
  • by coolsnowmen (695297) on Friday June 18, 2010 @10:57AM (#32613144)

    That total cost of 240$ is based on them acquiring used material at a radio swap meet, not scavenging it from old stuff I could find in my attic, and definitely no buying from some online supplier. That is, w/o a lot of luck, time, and knowledge- there is no way I could duplicate this effort with ease.

    • That total cost of 240$ is based on them acquiring used material at a radio swap meet, not scavenging it from old stuff I could find in my attic, and definitely no buying from some online supplier. That is, w/o a lot of luck, time, and knowledge- there is no way I could duplicate this effort with ease.

      Agreed. This is $240 only if you happen to have thousands of dollars worth of the right junk and test equipment lying around.

  • SAR is really cool (Score:2, Interesting)

    by Anonymous Coward

    I worked for a company started by a person who did SAR research in school. His project was based off an earlier one done by my current business partner at the time. A small rail track is still mounted on top of the engineering building at the university from these projects.

    The big difference with what that company, www.ImSAR.com, is doing and anyone else is the size. The system they developed is 2lbs and smaller than a shoebox. At the time, the next smallest system was 50 lbs. This little box can fly a a p

    • Re: (Score:1, Informative)

      by Anonymous Coward

      Found it: http://spectrum.ieee.org/computing/hardware/winner-radio-eye-in-the-sky

  • Old stuff (Score:1, Interesting)

    by Anonymous Coward

    I did this exact thing in 1984 in grad school for MSEE. Only it didn't require quite as much hardware as he used.

    At the time it was hush-hush because it was for Air Force to use on new bomber construction - B1 with stealth-like attributes.

    Cost more too. May have to revisit now that can find cheap parts.

  • God bless the Can-Do attitude at MIT (and elsewhere, I suppose). I wish they hadn't thrown my application away, and hope that the totally-awesome-just-not-MIT school that I'm going to will support this kind of thing.
  • by Animats (122034) on Friday June 18, 2010 @01:13PM (#32615006) Homepage

    I'm impressed with what this guy found at a hamfest. We don't see much microwave gear in Silicon Valley surplus any more. eBay, though, has a decent selection of microwave horns, low noise amplifiers, mixers, and waveguide. It looks like anybody could get the necessary parts in small quantity. New, though, those parts are expensive, so building low-cost robot vision systems this way is hard.

    Also, when your "garage machine shop" has a Bridgeport milling machine, you're way above the usual home shop level. Still, if there's a TechShop in your town, you can get access to such machines.

    A big problem working in this area, even if you know what you're doing, is that the test gear you need costs more than the thing you're making. Reading the design notes, some of which are on Air Force Research Lab stationery, indicate that the hamfest parts were tested and characterized using reasonably good test gear. And this was an MIT student, with access to MIT labs.

    I ran into that building a small LIDAR in the early 1990s. The parts cost wasn't too bad, but I needed access to about $20K in test gear to debug the thing.

    • Re: (Score:3, Informative)

      by stewbee (1019450)
      I actually know the author and I know how he came across the Bridgeport and test equipment. First, I will say that he did his PhD work at Michigan State, not at MIT. He does work for MIT Lincoln Labs, hence the MIT moniker everywhere. He acquired his test equipment usually from things like the Dayton Hamvention. I even picked up an oscilloscope myself there for about $50 when I went with him one year. As for the Bridgeport, he know of a machine shop that was getting rid of two Bridgeports. I think he offere
      • Re: (Score:3, Funny)

        by bugs2squash (1132591)
        A swap meat sounds like the kind of place one would go to find an organ donor, not a radar.
      • by Animats (122034)

        However, I will admit that this is certainly beyond the capabilities of most people due to the lack test equipment that is needed to even test the parts found at the swap meet.

        True. Although it is easier to get gigahertz test gear than it used to be, the typical 'scope won't go there. [tek.com]

  • by Anonymous Coward

    It's still amazing a humble little bat accomplishes essentially the same thing except with sound, especially given the computational resources fourier transformations require.

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