What could possibly be better than printing out a few low-resolution voxels on a MakerBot? A whole lot of things, but how about getting those voxels with your own synthetic aperture radar? That’s what [Gregory Charvat] has been up to, and he’s documented the entire process for us.
The build began with an ultra wideband impulse radar we saw a while ago. The radar is built from scraps [Greg] picked up on eBay, and is able to image a scene in the time domain, creating nice linear sweeps on a MATLAB plot when [Greg] runs in front of the horns.
With an impulse radar under his belt, [Greg] moved up the technological ladder to something that can produce vaguely intelligible images with his setup. The synthetic aperture radar made from putting his radar horns on the carriage of a garage door opener. The horns slowly scan back and forth along the linear rail, taking single impulse readings and adding them together in an image. In the video below, [Greg] is able to image a few pieces of copper pipe only a few inches in diameter. The necessary equipment for this build only cost [Greg] a few hundred bucks at the Dayton Hamvention, and a similar setup could be put together for even less.
If building an X band impulse synthetic aperture radar isn’t impressive enough. [Greg] also 3D printed one of his radar images on a MakerBot. That’s just applying stlwrite to the 2D radar image and feeding it into MakerWare. Gotta have that blog cred, doe. It also makes for the best headline I’ve ever written.
Continue reading “DIY Ultra Wideband Impulse Synthetic Aperture Radar And A MakerBot”
Learn why you were pulled over, quantify the stealthiness of your favorite model aircraft, or see what various household items look like at 10 GHz. In this post we will describe the basics of Synthetic Aperture Radar (SAR) imaging, beginning with a historical perspective, showing the state of the art, and describing what can be done in your garage laboratory. Lets image with microwaves!
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Sensors. The low-end stuff that we can get our hands on usually suffers from poor range, lack of sensitivity, and no way to characterize what the target is. But today we can use the good stuff that, until recently, was only available to military: radar. In this post we will discuss how radar works, commercially available small radar devices, and where to learn more to help make it easy to add radar to your next project. Reach out and sense something!
Continue reading “Guest Post: Try Radar for Your Next Project”
[Dr. Gregory Charvat] tipped us off to a video demonstration of his ultra-wideband impulse radar he built using some of his existing radar gear and a few bits purchased off eBay. The homebuilt radar system worked well in his backyard but not much is covered about the build. [Greg] is promising a new book on practical approaches to developing and using small radar devices titled “Small and Short Range Radar Systems“. He told us that the draft is finished and covers radar systems like doppler, linear FM, synthetic aperture, phase array and also UWB impulse radar. It sounds like an interesting book, which can be pre-ordered on Amazon, and will include schematics and bill of materials so you too could build a UWB impulse radar or other small radar systems. Some of the advantages of a UWB impulse radar system are that it produces sub-nanosecond pulses good for tracking moving objects as well as imaging stationery objects. Such radar technology can even image buried objects like metallic and nonmetallic landmines.
Join us after the break for a little background on [Dr. Gregory Charvat] and to watch his demonstration video.
Continue reading “Homebuilt Ultra Wideband Impulse Radar”
[Kalle] is currently building an FMCW radar, but as he doesn’t have all the parts finished he decided to build a 9GHZ doppler radar in the mean time. The H-plane horn antennas were made from brass sheet and soldered together. [Kalle] checked the matching between the emitter and the antenna by inserting a directional coupler between the two and measuring the intensity of the reflected signal (approximated return loss). At 9Ghz, the Doppler shift for a 1 meter per second speed is about 30Hz so he connected the radar’s output signal to his soundcard.
A quick explanation of the Doppler effect that a radar uses: if you send an RF signal at a given frequency to a moving target, the reflected signal’s frequency will be shifted. It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from an observer. The received frequency is higher (compared to the emitted frequency) during the approach, it is identical at the instant of passing by, and it is lower during the recession. Hackaday featured plenty of projects using this effect: a small doppler motion sensor, gesture control using doppler shift, hacking an old radar gun
We would be remiss if we didn’t mention that all of SparkFun’s open source hardware is now on Upverter.
Not wanting to tie up an iPad as a mini-gaming cabinet [Hartmut] hacked an Arcadi cabinet to use EUzebox instead.
Time travel happens in the bedroom as well. But only if you have your very own Tardis entrance. [AlmostUseful] pulled this off with just a bit of word trim and a very nice paint job. [via Reddit]
[Pierre] tricks an iPhone fingerprint scanner by making a replica out of hot glue.
Some of the guys from our parent company were over in Shanghai on business. [Aleksandar Bradic] made time to visit the Shanghai hackerspace while in town and wrote about the experience over on their engineering blog.
[Gregory Charvat] is a busy guy. In fact we’ve got a juicy hack of his saved up that we still need to wrap our minds around before featuring. In the mean time check out the Intern-built coffee can radar that he took over and tested on a multi-million dollar Spherical Near Field Range.
And finally, everyone loves coffee hacks, right? Here’s what [Manos] calls a Greek style instant coffee machine.
CAN Bus hacking is all the rage right now. This particular project uses an early development version of an Arduino compatible CAN bus tool to integrate radar detector control into a Mazda dashboard. This image shows the output as the Whistler Pro-3600 radar detector boots up. The self test demonstrates what you would see on the dashboard display if your speed is checked using any of a handful of technologies. But it’s not just the dash display that’s working. The steering wheel controls are also capable of affecting the radar detector so that it can always be hidden from sight.
With auto manufacturers adding more numerous and larger displays to our vehicles it’s refreshing to see someone come up with a hack that makes pushing our own info to those screens possible. The CANBus Triple is an Arduino compatible board which patches into the data bus found in all modern vehicles. To integrate the Whistler for this hack [TheDukeZip] prototyped the interface on a regular Arduino board, then moved it over to the CANBus Triple once he had it working. Check out the video after the break to see the setup in action.
Continue reading “Radar detector integrated with dashboard display screens and steering wheel controls”