From Hackaday:
A few profs from MIT’s Lincoln Lab are giving those poor MIT undergrads something to do over winter break: they’re teaching a three-week course on building a laptop-powered radar system capable of radar ranging, doppler, and synthetic aperture imaging. Interestingly, the radar system that teams will build for the class has a BOM totaling $360, and they’re alsoputting the entire class online if you’d like to follow along and build your own.
From the lecture notes from the course, the radio system is made out of an off-the-shelf LNA, oscillator, and splitter. By connecting two coffee can ‘cantennas’, it’s possible to record a .WAV file from the signal coming from the radar and use MATLAB to turn that audio signal into a Doppler radar.
It’s a very ambitious project that goes deep down the rabbit hole of RF and analog design. One of the lecturers made a YouTube demo of the radar in ranging mode; you can check that out below.
Comments
Check back on my website in a couple months for an announcement. I'm getting closer to being ready for production. I did not make an effort to get the airborne version working. It turns out to be a fairly complex problem to solve, though I'm sure someone will.
Tony
I have added a new entry on the testing of the RADARduino prototype.
http://reactancelabs.com/?p=293
Greg Charvat is the man! So many fun YouTube experiments. We got to interview him on The Amp Hour a few months back (just like the illustrious author of this post a few months prior to that ;-) ). He's great and the course really is seeing some widespread adoption now.
Greg is working with Tony over at Reactance Labs(@mmwave) to develop a friendlier, kitted version of this course called the RADARduino. Not out yet, but should make access to the course and the topics even better.
Can this design be readily improved to produce results with a SUAS? It seems like the 'cantennae' could use a little refinement and perhaps 2.4GHz is not the best for a SUAS application, especially with a low-powered 10mW Tx. I'd love to hear if something like this can be used to generate surface models.
@narwhal - this is a CWFM radar. It can be used for SAR under controlled conditions, but takes a long time to produce an image, and SAR produces an image in the direction perpendicular to the motion of the aircraft/radar. It is not the type of radar which would be of use for Sense and Avoid. There are no inexpensive off the shelf versions. From my experience if you build this as per the MIT tutorial and use a decent pair of patch antennas it will maybe barely be able to do SAR from a UAV, but it really will be very marginal. Brigham Young University has a UAV SAR radar which has been through 3 or 4 revisions and I think there is a commercial spin-off, but I'm sure the price tag is five figures in dollars. That unit is fairly capable - I know it is doing missions in the Arctic this summer mapping ice flows.
Given that this is easy to create, are there off-the-shelf versions? Could this be used for Sense and Avoid with other aircraft?
Doug -- you're probably right (I can't remember). Interesting to hear of your experience.
Uh Chris, didn't Ritchie have a blog about this 8-12 months ago? He was working on laying out the RF electronics on a PCB and stacking it with a processor board for use in a UAV.
The free lecture notes have been out for a long time. I built up this radar last spring. It works, but it is a fiddly thing. We did pretty well with it as a traffic speed radar, but never could get decent SAR imaging out of it.
@Alan - Octave will work fine. The MATLab code is not all that intense...
I wonder if Octave will work as a replacement for MATLAB. One way to find out, I guess...
Seems familiar! I think I saw something similar or possibly related in last year's DEF CON archives - a talk by Michael Scarito: Build your own Synthetic Aperture Radar
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