DIY Synthetic Aperture Radar 118
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."
Wave Motion Gun? (Score:2, Interesting)
Can you mount this on your car? Maybe torch the guy who cut you off in traffic?
SAR is really cool (Score:2, Interesting)
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 payload on an 18 pound UAV. Check out the website for some pretty cool images of the unit and generated SAR images. IEEE Spectrum magazine did a cool piece on it in the Jan 2009 issue.
The system was running an ARM with montavista and did realtime (within a few seconds) calculations to transmit the video down to the observer. The antenna is a printed PCB and is mounted on a gimbal that moves using RC airplane control servos. To test the thing quickly, we'd hop in a car and mount it to a bracket on the window and go cruise around town. Definitely got some strange looks doing that. The boss even was once stopped by the cops because of "suspicious activity" that had been reported. Since then, they've now build a small RC plane that can fly it around for quick testing instead of a car.
Re:A lot more than 240 (Score:3, Interesting)
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.
Old stuff (Score:1, Interesting)
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.
Got all the microwave parts at hamfests? (Score:3, Interesting)
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.
Cool Technology, but ... (Score:1, Interesting)
It's still amazing a humble little bat accomplishes essentially the same thing except with sound, especially given the computational resources fourier transformations require.
The point isn't the specific price (Score:3, Interesting)
$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 build this stuff.
If nothing else, this has significant ramifications for asymmetric military conflicts...