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Radar Expert Explains How To Cheaply Add Radar To Your Own Hardware Projects
szczys writes "Gregory Charvat has been playing with and teaching others about entry-level radar concepts for a long time. Now he's sat down and explained how you can do it yourself inexpensively. He says, 'One enabling technology for Radar was the cathode ray tube (CRT), which facilitated a method of measuring the time delay between transmitted and received waveforms. ... Today, rather than using a CRT we can use high-speed digitizers. This offers the obvious advantage of applying signal processing to acquired data so that only moving targets are detected, tracking can be achieved, imaging, and a multitude of other modes. But for hobbyist and consumer projects we do not need this much power, range, and can not afford the cost. We need the ability to sense like a long range radar (detecting only moving targets, imaging, Doppler, signatures, etc) but at short ranges and at low costs.' Charvat then proceeds to walk through several options for the amatuer hardware hacker."
What tech do auto makers use for the proximity detectors in car bumpers?
Seems like that'd be an inexpensive, short range detector, even if it's not radar.
Dunno about where you live, but around here, police use LIDAR which is much more difficult to deal with for the would be detector/jammer.
LIDAR is pretty much impossible to detect until it's pointing right at you, at which point the best you can do is try to jam it long enough to slow down (which is pretty damn obvious when the cops LIDAR gun goes nuts as soon as he points it at your car).
Obligatory link
Ezekiel 23:20
The new single-chip radar solutions and FMCW radar modules are definitely much easier to use and more capable than what was available just a few years ago, but DIY radar is nothing new. Amateur radio operators have been playing with radar guns and door sensors for decades, and doing some pretty interesting things with them. I remember reading photocopies of articles from QST from the 1970's that explained how to hack door sensors to make speed detectors, as well as using them for long-distance voice and video transmission with parabolic reflectors. People have also been playing with marine radar, which is considerably more expensive but still affordable for a dedicated experimenter.
I am a geek attorney, but not your geek attorney unless you've already retained me. This is not legal advice.
What is a CRT? It it pronounced like Kurt, or CeeeArrrrrTeeee? Do they come with any cool apps? I do like the idea of my own ray tube though. Sounds pretty up and coming. Anybody know of any upcoming IPOs investing in this tech?
Now if I can only find a shark...
Table-ized A.I.
Dunno about where you live, but around here, police use LIDAR ...
THAT's why I covered my ride in black velvet.
When our name is on the back of your car, we're behind you all the way!
Those are probably ultrasound. Ultrasound distance sensors are available at Radio Shack and included in Lego Mindstorm kits.
According the the Jargon File, the definitive dictionary of hacker terminology, the word "hacker" ORIGINALLY referred to radio experimenters who did things like make or modify radar units. Later, it was used to describe people doing similar hacks with computer systems.
So those "kids directing laser pointers towards airplanes" could in reality be officers mishandling their LIDARs? And, BTW, if pointing lasers at pilots/drivers is such a serious thing, why are police officers allowed to do it?
Well for one thing it's a low intensity infrared beam which is eye-safe and invisible.
Kinda apples and grenades there..
The low intensity _invisible to the human eye_ light from a LIDAR gun would never make it anywhere near an airplane, and even if it did, being invisible and all, it wouldn't matter.
Additionally, they are usually of low enough intensity and/or in a non-eye-focusing wavelength to be completely safe to the human eye. YOu could literally stare right into one with no adverse effects.
Problem is; most places in North America and I imagine Europe as well, already have laws on the books covering illegible or obscured registration tags and these covers often fall on the wrong side of the law. Personally, I'd rather get the speeding ticket than a missing/illegible plate ticket and would really really like to avoid any possible "obstruction of a police officer in the performance of his duties" charge.
Something else to consider; based on what seems to be the growing trend in the US: Do you want to get a speeding ticket which usually isn't a criminal act and only nets you a fine Or do you want to use a device whose (arguably) sole purpose is to break the law with impunity, leading to your car being declared as property used in the commission of a crime and confiscated? (while you get beaten half to death and charged with resisting arrest) If you speed, you are only in violation when you speed, but if you put a contraband plate cover on, you are in violation just parked on the street
I need a wheelchair van for my son. Help me get the word out. https://www.gofundme.com/wheelchair-van-for-jj
Well, It's wrong. A Hacker originally was anybody who built or modified electronics
(not just Radar).
I know, I was there.........
I don't suppose you have any early text using the term? The jargon file itself is pretty old now. If you have a clear use of the term much earlier it could be of historical interest to many people.
Ozoner, would you say "I knew the original hacker. The original hacker was a friend of mine. Dan, you're no original hacker"? :)
For anybody who knows... could a radar system partly or completely side-step the Doppler Dilemma ( http://en.wikipedia.org/wiki/W... ) by doing DSS or FHSS and cycling through a sequence of different carrier frequencies from pulse to pulse?
Might as well drive through a bunch of muddy puddles. Cheaper, and you can say "Sorry officer I didn't realize. I'll go wash it off as soon as I get home." Who knows, it might even work too.
SHHH! It works only too well, my friend, especially in rural areas on a 4x4 ...
Google finds content, it doesn't create content. Google found that definition somewhere, and we don't know where. Therefore citing Google is precisely the same thing as saying "some random web site says ..."
Additionally, jargon file is maybe 20-25 years older than Google, so for the _original_ meaning of a term jargon file trumps Google by a long shot.
Most cars round where I live don't bother cleaning their number plates... the chances of actually being picked up by a ploice road patrol that could be bothered to do the stop are pretty slim. And if they were picked up, they have a simple excuse which should not really be allowed to stand as by law, your vehicle is supposed to be roadworthy which includes having legible plates and you're supposed to check certain things daily.
Donald 'Duck' Dunn: We had a band powerful enough to turn goat piss into gasoline.
Some adaptive cruise control systems (e.g. Nissan's) and laser parking sensors are known to interfere with speed guns using LIDAR. They are legal because they are a safety device, not a jamming device, and the police equipment just happens to be incompatible. That band (~900nm) is license free, interference is expected.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
I once knew a guy (20+ years ago) who had a microwave element mounted in front of his radiator, the radiator shielding him from the glorious waves. He had his radar detector wired to trigger the microwave when it detected a radar gun signal, effectively roasting the radar gun.
At least this is what he told me.
I think he did this after getting fed up with Connecticut State Troopers, their speed traps and unmarked Ford Tauruses and Jeeps pulling people over at 56 miles an hour. Setting my memory back to 20 - 30 years ago, I don't blame him one bit.
- Zav - Imagine a Beowulf cluster of insensitive clods...
Speeding isn't the crime I was referring to, since most places consider most traffic offences to be a civil, not criminal offence. However, use of a device or substance to deliberately obscure your licence plate may or may not be part of the traffic code where you live, but rather covered by the criminal code. If use of a cover plate is considered a criminal act where you live, then the car is being used in the commission of a criminal act even when it's safely parked in your driveway. Having a plate obscured on a dirty vehicle by mud or snow is plausibly neglect, there's no clear proof of intent to evade the law. Thus; most police officers will give you a warning or a "fix-it ticket". But purchasing and installing a device whose sole advertised purpose is to evade detection by police as you break traffic laws inherently displays intent to do exactly that.
Please note that I also said "...in the US". There have been numerous news stories about law abiding people being pulled over for no more reason than having a nice car with out of state plates, having their vehicles searched and cash confiscated as "proceeds of crime" even when there is NO other evidence of any crime. People who then try to protest this get beaten up and charged with resisting arrest. My reasoning is this: If certain officers and/or certain police departments are using any pretext at all to pull someone over and search for things they can confiscate to support their department financially, I certainly don't want to risk driving around with one of the license obscuring items on my car.
I need a wheelchair van for my son. Help me get the word out. https://www.gofundme.com/wheelchair-van-for-jj
A little more work with the jammer and the police will not easily figure out who it was, nor find the device.
I'm intrigued. Low power radar ain't that hard to defeat. Lidar isn't either, and you don't need flares.
deleting the extra space after periods so i can stay relevant, yeah.
Dunno about where you live, but around here, police use LIDAR ...
THAT's why I covered my ride in black velvet.
The fact he's also a pimp is entirely coincidental.
Calling someone a "hater" only means you can not rationally rebut their argument.
Google finds content, it doesn't create content. Google found that definition somewhere, and we don't know where. Therefore citing Google is precisely the same thing as saying "some random web site says ..."
Additionally, jargon file is maybe 20-25 years older than Google, so for the _original_ meaning of a term jargon file trumps Google by a long shot.
If Google cant find your "Jargon File", how the hell will i ever find it? lol
Please, for the love of God, link this "Jargon File" and prove me wrong :)
When I search, the first 15 Google results for Jargon file are correct. The third one is the entry for "hacker", which is interesting. In case your Google is broken, the primary copy is http://www.carb.org/jargon/
Have you seen the xkcd about diet Coke and Mentos? It kind of expresses how I feel right now, getting the honor of introducing you to a classic bit of geekdom. Sergey and Larry almost surely would have read the Jargon File when they were in college.
My post has a typo. That should be http://www.catb.org/jargon/
Catb is Eric S. Raymond's page. If you're not familiar with ESR yet, he's pretty awesome. I highly recommend two of his essays, "How to Ask Questions the Smart Way" and "the Cathedral and the Bazaar".