Radar Expert Explains How To Cheaply Add Radar To Your Own Hardware Projects 69
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."
Re:My interest (Score:5, Interesting)
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).
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Dunno about where you live, but around here, police use LIDAR ...
THAT's why I covered my ride in black velvet.
Re:My interest (Score:5, Interesting)
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
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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 ...
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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 sub
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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.
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Re:My interest (Score:5, Informative)
Well for one thing it's a low intensity infrared beam which is eye-safe and invisible.
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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.
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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.
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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 -
Re: My interest (Score:2)
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.
What's in car bumpers? (Score:1)
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.
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I have a family member with a Ford Focus. This has reversing sensors that warn you if you are about to reverse into something.
Whatever tech those are using seems like it would be good to try out.
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I have a family member with a Ford Focus. This has reversing sensors that warn you if you are about to reverse into something.
Whatever tech those are using seems like it would be good to try out.
At least "trickle down" works in automotive tech. First I learned about them was when I tried to back a rented Lincoln into a wall and the alert went off. Thankfully.
Now there's backup cameras in the new Honda Civic.
Re:What's in car bumpers? (Score:5, Funny)
Ffft, we had an audible proximity alarm in our car before it became fancy. When you heard the bumper crunch, you knew you went too far.
So it was very close proximity. So?
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Ffft, we had an audible proximity alarm in our car before it became fancy. When you heard the bumper crunch, you knew you went too far.
So it was very close proximity. So?
I detected a Cadillac that way once, alas.
Re:What's in car bumpers? (Score:4, Informative)
Utrasonic SONAR is used for parking proximity parking sensors.
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Additional impulse radar systems are being manufactured in quantity for automotive applications (blind spot detection, parking aids, etc), but details on these are not easy to find unless you directly engage the manufacturers. Manufacturers of automotive radar equipment include, Delphi, Continental, TRW, Bosch, Denso, and Autoliv.
Some vehicles may use sonar. The article claims that at least come manufacturers are using a form of radar.
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Radar tends to be used for the collision avoidance features rather than the parking assistance stuff.
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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.
Ultrasonic. They were selling experimenter units at Radio Shack when I was in there last month. For general use, not specifically for automotive mounting. I think in retail, they're about $30.
probably ultrasonic. Lego, Radio Shack has it. (Score:2)
Those are probably ultrasound. Ultrasound distance sensors are available at Radio Shack and included in Lego Mindstorm kits.
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How about these? [aliexpress.com]
Re:What's in car bumpers? (Score:4, Insightful)
What tech do auto makers use for the proximity detectors in car bumpers?
Ultrasonics. Just like the old Polaroid Camera auto-focus.
http://www.northerntool.com/sh... [northerntool.com]
MIT OCW (Score:2)
Easier now, but not new to ham radio guys (Score:5, Interesting)
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Silly Acronyms (Score:2, Funny)
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It's like a CRO, but considered more general purpose, more entertaining, but less useful to the tech head.
Which is funny, as the average CRT just hums gently, while a CROw is pretty noises (Vaaark!)
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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?
If only there was a way a person could use Google to do a quick search to find out what a CRT is. If that were possible, then you wouldnt even need to spend all that time and effort to post a question on a Slashdot article in the vain hope somebody will tell you the answer.
If only there was a way to use Google, everybodys life would be so much easier.
Maybe some day a smart person will figure out a way to do this, but unfortunately it looks like you will have to wait for your answer. Sucks to be you.
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Re: Silly Acronyms (Score:2)
Whoosh.
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It refers to the C Run Time, aka. the C standard library. Back in the day, only C programmers were able to operate radar. Nowadays, they can monitor radar with jQuery and node.js.
Almost there (Score:1)
Now if I can only find a shark...
Jargon file: hacker meant radio hardware before CS (Score:2)
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.
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Well, It's wrong. A Hacker originally was anybody who built or modified electronics
(not just Radar).
I know, I was there.........
any early citations in your attic (or PDP)? (Score:2)
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"? :)
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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.
Seems referencing some proof to backup claims on Slashdot isnt the way to go anymore.
Just look at my Google reference with 0 scores... :)
jargon file predates Goog by 20 years, is a source (Score:2)
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.
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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 :)
any of the first 15 Google results (Score:2)
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/ [carb.org]
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.
typo: catb.org, ESR's page (Score:2)
My post has a typo. That should be http://www.catb.org/jargon/ [catb.org]
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".
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My post has a typo. That should be http://www.catb.org/jargon/ [catb.org]
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".
Thanks for the sharing the link, will have a good read :)
Question about "Doppler Dilemma" (Score:2)
For anybody who knows... could a radar system partly or completely side-step the Doppler Dilemma ( http://en.wikipedia.org/wiki/W... [wikipedia.org] ) by doing DSS or FHSS and cycling through a sequence of different carrier frequencies from pulse to pulse?
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It's easier than that - use two blocks of different repetition frequencies (which gives two different Nyquist velocities), get two velocity readings. Some basic number theory will get you the right answer.
Using two different carriers is going to alter the Nyquist velocity by such a small amount that it's not worth doing. Unless the carriers are very widely separated (go from say, 2.7 GHz to 5.8 GHz) but this requires a wideband (and necessarily low gain) antenna.
That's not to say that FHSS is not used b