chad@ucscb.UCSC.EDU (darknight) (01/17/90)
[If you can read this line, your Line-Eater is out of order] All this talk about Radar detectors and Radar Jamming, I just thought you all might as well know... Last summer (1989), I read an article in Omni magazine (either June, July, or August) that described a new toy that the Police are testing out. Seems they now are using Laser based guns to measure car speeds. These have the advantage that they can target INDIVIDUAL cars up to 1000 ft. (and perhaps more), and even if someone does invent a laser detector, ala. radar detectors, by the time you detect the beam, you're PEGGED! (Companies will probably make and sell a bunch of them anyways.) In any case, it looks like the future of speeder detection is coming. The scary thing was that the guns are currently being tested at just a select few police departments, and the article showed a picture of a Police officer holding his new toy, and behind him in BOLD letters was a sign saying "Palo Alto Police Department"! I've driven through Palo Alto MANY times for shopping, etc. and I live nearby (except while I'm at College). Figures that Silicon Valley would be in the Vanguard of new Police Technology. :-) :-) In any case, I wouldn't be surprised if ALL radar detectors are rendered obsolete, unless the public reacts with massive hysteria towards the police having "Laser Guns". Any of you Grocery Store Scanner gurus care to respond? :-) -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ INTERNET: chad@ucscb.ucsc.edu Chad 'The_Walrus' Netzer->AmigaManiac++ ---=== If you can read this, then you're at the end of the posting ===---
besler@egrunix.UUCP (Brent Besler) (01/18/90)
I posted on rec.autos and sci.electronics about the laser speed measuring device back in November. I got some info from a Popular Mechanics editor on it. It is telescopicly aimed. To the best I can determine it uses a GaAs laser diode around .9 microns in wavelength(just beyond the visible in the IR). It is pretty low power since it is a Class I laser device. The detection apparatus is going to have to be pretty sensitive on it, since reflection from a car won't be that high. It works on computing succesive distances rather than a doppler effect. It runs about $3000, so it is about 3 times more than current radar units. It can't be used while moving currently since it can't determine the police cars speed yet. It should be possible to reduce the effective range by using daytime headlight. They have a high output(halogen particularly) around .9 microns. The beam is very narrow about 0.2 degress, so a detector will be useless, before it is too late. Brent H. Besler
mikemc@mustang.ncr-fc.FtCollins.NCR.com (Mike McManus) (01/18/90)
In article <349@egrunix.UUCP> besler@egrunix.UUCP (Brent Besler) writes: > (Discussing laser speed detectors...) > It can't be used while moving currently since it can't determine the police > cars speed yet. Why is that? How do the current radar models work with respect to telling the speed of the officer's car? Wouldn't it be similar? -- Disclaimer: All spelling and/or grammer in this document are guaranteed to be correct; any exseptions is the is wurk uv intter-net deemuns. Mike McManus (mikemc@ncr-fc.FtCollins.ncr.com) NCR Microelectronics 2001 Danfield Ct. ncr-fc!mikemc@ncr-sd.sandiego.ncr.com, or Ft. Collins, Colorado ncr-fc!mikemc@ccncsu.colostate.edu, or (303) 223-5100 Ext. 360 uunet!ncrlnk!ncr-sd!ncr-fc!garage!mikemc
jjd@bbn.com (James J Dempsey) (01/18/90)
chad@ucscb.ucsc.edu (darknight) writes: >> In any case, I wouldn't be surprised if ALL radar detectors >> are rendered obsolete, unless the public reacts with massive hysteria >> towards the police having "Laser Guns". Any of you Grocery Store >> Scanner gurus care to respond? :-) Things look bad on the detector front with respect to laser speed measuring devices. However, since we're not talking about radio waves, it would not be illegal to sell and operate a laser-device jammer. This might be more feasable than a detector. --Jim Dempsey-- jjd@bbn.com
kimf@tybalt.caltech.edu (Kim Flowers) (01/18/90)
You could disguise a laser-gun fooler :) as one of those funky brake lights you see flashing in strange patterns on yuppie cars everywhere! mAd_QuArK!
erc@khijol.UUCP (Edwin R. Carp) (01/18/90)
In article <349@egrunix.UUCP> besler@unix.secs.oakland.edu.UUCP (Brent Besler) writes: >yet. It should be possible to reduce the effective range by using daytime >headlight. They have a high output(halogen particularly) around .9 microns. >The beam is very narrow about 0.2 degress, so a detector will be useless, before >it is too late. Interesting idea. Put a couple of unfocused halogen bulbs on your car and presto! -- instant laser jammer. I HATE radar/laser (and I'm an ex-cop). -- Ed Carp N7EKG/5 (28.3-28.5) uunet!cs.utexas.edu!khijol!erc Austin, Texas (512) 832-5884 "Good tea. Nice house." - Worf "The best diplomat I know of is a fully activated phaser bank." -- Scotty
berryh@udel.edu (John Berryhill) (01/18/90)
In article <51058@bbn.COM> jjd@BBN.COM () writes: > However, since we're not talking about radio >waves, it would not be illegal to sell and operate a laser-device >jammer. Precisely. I'd just love to see those FCC bastards try to regulate optical frequencies. -- John Berryhill 143 King William, Newark DE 19711
josephc@tybalt.caltech.edu (Joseph Chiu) (01/18/90)
chad@ucscb.UCSC.EDU (darknight) writes: > In any case, I wouldn't be surprised if ALL radar detectors >are rendered obsolete, unless the public reacts with massive hysteria >towards the police having "Laser Guns". Any of you Grocery Store >Scanner gurus care to respond? :-) What about telling the public that the laser beams, when properly used, can cause severe damage to a driver's eye, or that it can burn paint off a car? If anything, we can demand a health-hazzard testing to stall implementation. Can you imagine a sign that reads: SPEED ENFORCED WITH LASER?
EAKIN@rsmas.miami.edu (01/18/90)
In article <349@egrunix.UUCP>, besler@egrunix.UUCP (Brent Besler) writes: > It can't > be used while moving currently since it can't determine the police cars speed > yet. I thought that the units were tied into the car spedometer to adjust for police car speed. Shouldn't that work? Besides, with the narrow angle, more precise aim would indicate that stationary use would be better anyway. Now, since it's optical, it should be possible to use irregular matte finishes and honeycomb materials to inhibit proper returns. The Stealth mobile lives! > Brent H. Besler -- C. Mark Eakin Internet: Eakin@RSMAS.miami.edu Univ. of Miami, RSMAS-BLR
henry@utzoo.uucp (Henry Spencer) (01/19/90)
In article <MIKEMC.90Jan17132215@mustang.ncr-fc.FtCollins.NCR.com> mikemc@mustang.ncr-fc.FtCollins.NCR.com (Mike McManus) writes: >> It can't be used while moving currently since it can't determine the police >> cars speed yet. > >Why is that? How do the current radar models work with respect to telling the >speed of the officer's car? Wouldn't it be similar? No; remember the laser system is doing distance measurement, while the radars are using Doppler velocity measurement. The radars simply measure the velocity of the background, which is always "in view" anyway because their beams are so broad. That doesn't work for the lasers. -- 1972: Saturn V #15 flight-ready| Henry Spencer at U of Toronto Zoology 1990: birds nesting in engines | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
henry@utzoo.uucp (Henry Spencer) (01/19/90)
In article <8561@nigel.udel.EDU> berryh@udel.edu (John Berryhill) writes: >> However, since we're not talking about radio >>waves, it would not be illegal to sell and operate a laser-device >>jammer. > >Precisely. I'd just love to see those FCC bastards try to regulate >optical frequencies. Sigh, for the Nth time: interfering with the police is illegal, highly so, no matter how you do it. If it becomes a problem, the police will most assuredly get themselves set up to detect such jamming and will come down hard on people who do it. The FCC is irrelevant. (My sympathies lie with the speeders, actually, but claiming that you have a God-given right to jam the police is folly approximating Canute ordering the tide not to come in. Remember, your opponents in this particular game are also the folks who make the rules, and change them when they see fit.) -- 1972: Saturn V #15 flight-ready| Henry Spencer at U of Toronto Zoology 1990: birds nesting in engines | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
besler@egrunix.UUCP (Brent Besler) (01/19/90)
>I thought that the units were tied into the car spedometer to adjust for police >car speed. Shouldn't that work? In general the speedometer in the cop car may be off a couple of MPH, and that can make big a big difference with regard to fines, etc. Radar gun aren't wired into a cops speedometer. They use a separate radar beam to determine the speed of the cop car relative to the ground. > >Besides, with the narrow angle, more precise aim would indicate that stationary >use would be better anyway. Yes, but it would be conveient to have moving use capability. >Now, since it's optical, it should be possible to use irregular matte finishes >and honeycomb materials to inhibit proper returns. The Stealth mobile lives! A black car is going to reflect the leat light in the near IR. I am sure the IR detector in the device has to be very sensitive, as I am sure the desigeners too it into account. The only device being made yet is made by International Measurement and Control. The probably have a patent since there is a very large potential market for this device. Brent H. Besler
besler@egrunix.UUCP (Brent Besler) (01/19/90)
The IM&C device is a Class I laser device, which means its use is basically un regulated. The power output is pretty low. It uses rapid, very short duration pulses. Similar devices have been used for years to measure distances in the military and construction. This device just computes speed from succesive distance measurements. Wether or not halogen bulb output will jam it is anybodies guess. I am sure it has a filter to admit only the .9 micron wavelength. The sophistication of the detction electronics would play a part in the effectuveness of jamming. Good electronics will be able to filter out background radiation of the .9 nm frequency. The advantage of the jamming light is that its intensity varies as the square of the distance whereas the received intesnity of the meauring laser will vary as the fourth power of the distance. Brent H. Besler
koontz@oregon.sgi.com (David Koontz) (01/19/90)
In article <8561@nigel.udel.EDU>, berryh@udel.edu (John Berryhill) writes:
The state of California, in a interesting contradiction to the use
of laser speed measuring devices within the state, passed a law banning
shining lasers, as a result of the use of lasers against drug sniffing
helicopters.
Has anyone got the text to see if it covers the use against cars? I
believe it does.chuck@mitlns.mit.edu (01/19/90)
-Message-Text-Follows- In article <354@egrunix.UUCP>, besler@egrunix.UUCP (Brent Besler) writes... >The IM&C device is a Class I laser device, which means its use is basically un >regulated. The power output is pretty low. It uses rapid, very short duration >pulses. Similar devices have been used for years to measure distances in the >military and construction. This device just computes speed from succesive >distance measurements. Wether or not halogen bulb output will jam it is >anybodies guess. I am sure it has a filter to admit only the .9 micron >wavelength. The sophistication of the detction electronics would play a part >in the effectuveness of jamming. Good electronics will be able to filter out >background radiation of the .9 nm frequency. The advantage of the jamming >light is that its intensity varies as the square of the distance whereas the >received intesnity of the meauring laser will vary as the fourth power of >the distance. Not so! the laser beam is so small that ALL of it hits your car and is reflected back. Thus unless the air is dirty (absorptive) it will fall off as 1/r**2. Chuck Parsons CHUCK@MITLNS.MIT.EDU
wiz@xroads.UUCP (Mike Carter) (01/19/90)
In article <1061@khijol.UUCP>, erc@khijol.UUCP (Edwin R. Carp) writes: > > Interesting idea. Put a couple of unfocused halogen bulbs on your car and > presto! -- instant laser jammer. > > I HATE radar/laser (and I'm an ex-cop). > -- > Ed Carp N7EKG/5 (28.3-28.5) uunet!cs.utexas.edu!khijol!erc I can see it now... 4 years down the road...during the day cars go by with glittering fountains of bright light explosions and at night laser beams zip back and forth. The cops, now in desparation from all of the counter measures, counter-counter measures, and legal laser tape resort back to stop-watch ticketing and highway shadowing to match speed tactics. The public, enraged by this starts a massive legal campaigne to BAN the SPeed limit entirely. This in turn succeeds, the polic departments loose major amounts of funding and turn to busting jaywalkers. In the meantime, the freeway carnage has reached an all time high.. ambulance crews now spend their shifts spaced 2 miles apart on the freeways. Radar detector door stops are in vogue and laser cannon jammers are hung from rear view mirrors and gain the status much like that of those furry dice dingle balls you see in low-riders. And to think the cops believed the public wanted the speed limits to be enforced anyway... "There is a certain resolute madness in the art of avoiding defeat." -Harllan Ellison ailiamentary canal extraordinaire
sorka@ucscb.UCSC.EDU (Alan Waterman) (01/19/90)
Sorry but you're wrong. Halogen lights are legal. They will most likely jam the lasers. This will interefere with the police. Thus it is not illegaL
sorka@ucscb.UCSC.EDU (Alan Waterman) (01/19/90)
Are you sure the light intensity with vary 1/(distance^4) That makes sense if the source emmits in a sphere, reflects and comes\ back as a sphere. But the laser shoots in a strait line so almost all the light from the source reaches the destination. Am I wrong about the laser beam?
whit@milton.acs.washington.edu (John Whitmore) (01/19/90)
The possibility of filtering the reflected light so that only a small part of the spectrum is actually measured makes jamming nearly impossible for these babies; a laser (even a cheap diode laser) can easily outshine the sun for watts/steradian/MHz_bandwidth. On the medium tech side, though, a diffraction grating could be built and blazed to take the laser beam and reflect it 45 degrees from its incoming direction, so the reflection always misses the sensor in the gun. Diffraction gratings are cheap and not difficult to build for long wavelength (like infrared). So, you can get a large grating and employ decoupage (basically making it part of the paint job). It looks normal in visible light, but the laser reflection misses the cop's gun. As for interfering with the police, that's a non-issue; what American jury would support the claim that such a paint job is interference? The various governments, and their police, have no particular rights to ease of observation of suspects. It is the suspects whose privacy rights are most clearly laid out in US law. Canada, of course, has a different constitution. I am known for my brilliance, John Whitmore by those who do not know me well.
EAKIN@rsmas.miami.edu (01/19/90)
In article <353@egrunix.UUCP>, besler@egrunix.UUCP (Brent Besler) writes: > > In general the speedometer in the cop car may be off a couple of MPH, and that > can make big a big difference with regard to fines, etc. Radar gun aren't > wired into a cops speedometer. They use a separate radar beam to determine > the speed of the cop car relative to the ground. OK, so why not encorporate a small secondary radar, with a beam focused at the ground very near the police vehicle (or even behind it) for a speed reference? The repeated distance measures on the target vehicle should work just as well when both vehicles are moving. > >>Now, since it's optical, it should be possible to use irregular matte finishes >>and honeycomb materials to inhibit proper returns. The Stealth mobile lives! > > A black car is going to reflect the leat light in the near IR. I am sure > the IR detector in the device has to be very sensitive, as I am sure the > desigeners too it into account. Who said anything about black? What we need is IR/near IR absorbance, the visible spectrum color is independent. For reference, look at the colored boat tops that are selectively transparent to UV-A tanning rays. -- C. Mark Eakin Internet: Eakin@RSMAS.miami.edu Univ. of Miami, RSMAS-BLR
dnewton@carroll1.cc.edu (Dave Newton the Late) (01/19/90)
We here at Carroll (well, actually, Dave sitting next to me) has solved the laser speed detector problem: He suggests a black felt car. Not only would it probably absorb the beam, but it would feel good too. Nice upholstery, inside and out. Large smiley. -- David L. Newton | uunet!marque!carroll1!dnewton (414) 524-7343 (work) | dnewton@carroll1.cc.edu (414) 524-6809 (home) | 100 NE Ave, Waukesha WI 53186 I'm looking for Tom Brown, Chem. Eng. major at UofIL, Junior. Tell him to call
dnewton@carroll1.cc.edu (Dave Newton the Late) (01/19/90)
In article <1105@carroll1.cc.edu> dnewton@carroll1.cc.edu (Dave Newton the Late) writes:
: He suggests a black felt car. Not only would it probably absorb the beam,
:but it would feel good too. Nice upholstery, inside and out.
New addendum: A painting of Elvis on the side is optional equipment.
Unfotunately, this could lead to easy identification.
--
David L. Newton | uunet!marque!carroll1!dnewton
(414) 524-7343 (work) | dnewton@carroll1.cc.edu
(414) 524-6809 (home) | 100 NE Ave, Waukesha WI 53186
I'm looking for Tom Brown, Chem. Eng. major at UofIL, Junior. Tell him to callhenry@utzoo.uucp (Henry Spencer) (01/20/90)
In article <7333@lindy.Stanford.EDU> sorka@ucscb.UCSC.EDU (Alan Waterman) writes: >Sorry but you're wrong. Halogen lights are legal. They will most likely >jam the lasers. This will interefere with the police. Thus it is not >illegaL Halogen lights are legal. I would not be so sure that they will jam the lasers. If I were designing such a laser system, the very least I'd do would be a very narrow bandpass filter on the receiver, plus circuits to ignore steady background and listen only to pulses. There are a variety of more sophisticated things that could be done -- see any book on radar that talks about ECCM (Electronic Counter-CounterMeasures). The most your halogen lights would do is reduce the range slightly (by reducing signal/noise ratio a bit), unless you do something elaborate and conspicuous and less obviously legal like pulsing them. Even that might not help, since the laser pulses will be very short and sharp-edged and I don't think halogen lights can imitate that very well. The suggestion for a diffraction-grating paint job is much more clever. It wouldn't be perfect, but it might cut the S/N ratio enough to make things difficult. -- 1972: Saturn V #15 flight-ready| Henry Spencer at U of Toronto Zoology 1990: birds nesting in engines | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
besler@egrunix.UUCP (Brent Besler) (01/20/90)
I looked into the reflectance of near IR as much as I could. I borrowed a book on IR devices from a physics friend. There were some charts on specular IR reflectance. Near IR reflectance from paint behaves very much like read light. Red will reflect most of it and so will white paint. Black reflects the least. It is probably possible to build a jammer out of the same variety of IR laser, but the problem is knowing the right pulsing rate. If the device is built well jamming may be pretty hard and the cop will know who jamming him much more than with radar since the device is aimed at a specific car. A scanner may be much more effective at spotting a laser speed trap. A small auxiliary radar could be mounted on a cop car to determine its speed. It should be pretty low power to avoid detection by radar detectors. Brent H. Besler
besler@egrunix.UUCP (Brent Besler) (01/20/90)
In article <7334@lindy.Stanford.EDU> sorka@ucscb.UCSC.EDU (Alan Waterman) writes: > >Are you sure the light intensity with vary 1/(distance^4) >That makes sense if the source emmits in a sphere, reflects and comes\ >back as a sphere. But the laser shoots in a strait line so almost >all the light from the source reaches the destination. Am I wrong about >the laser beam? I am a chemistry type, not an optics expert, but I think it goes as follows: The intensity of any em radiation beam goes down as 1/(distance**2). THe laser beam on the speed measuring device is about 4 ft. wide at 1000 ft. Only a small portion of the beam will be reflected back at the car. The relfection from the car behaves as if it were another light source(in a model treatment anyway). Brent H. Besler
ron@hpfcso.HP.COM (Ron Miller) (01/20/90)
Re: Laser jamming In the endless cycle of measure and counter-measure, chances are that once people start using halogen anti-laser lights, the police units will encode their outputs in order to identify their returns. War is hell. Ron Miller
carroll@bcsaic.UUCP (Jeff Carroll) (01/20/90)
In article <8561@nigel.udel.EDU> berryh@udel.edu (John Berryhill) writes: >Precisely. I'd just love to see those FCC bastards try to regulate >optical frequencies. Which federal agency *is* it that regulates lasers? Isn't it the FDA?
sorka@ucscb.UCSC.EDU (Alan Waterman) (01/20/90)
Then you are saying that the laser is actually just laser light and not a beam? If it is a beam, then all of the light will reach one source and will disperse very little until it reaches that source.
gene@cooper.cooper.EDU (Gene (the Spook) ) (01/20/90)
in article <MIKEMC.90Jan17132215@mustang.ncr-fc.FtCollins.NCR.com>, mikemc@mustang.ncr-fc.FtCollins.NCR.com (Mike McManus) says: > In-reply-to: besler@egrunix.UUCP's message of 17 Jan 90 16:03:38 GMT > > > In article <349@egrunix.UUCP> besler@egrunix.UUCP (Brent Besler) writes: >> (Discussing laser speed detectors...) >> It can't be used while moving currently since it can't determine the police >> cars speed yet. > > Why is that? How do the current radar models work with respect to telling the > speed of the officer's car? Wouldn't it be similar? For a semi-educated guess, how 'bout this: The way mobile radar works is that you spit out a beam and collect two inputs. The first is the signal reflected from stationary objects, such as trees, signs, etc. If the squad car is moving at 55mph, the reflected signal should be 55mph. The second signal would be that of the alleged speeder. If, for example, the target is going 70mph, the reflected signal should indicate 15mph. By taking the difference, you can calculate the alleged speeder's speed. With a laser ranging system, I guess that you have to "paint" the target with a laser beam and read the interference pattern to determine the target's speed. Both systems work because of the doppler effect, but the laser can read only one interference pattern (so far). Interestingly enough, it seems as though the laser-type system is like that of laser-guided missiles, from what I've read. Also, call Cincinnati Microwave (of Escort and Passport fame) and ask for their "Why Radar Guns Are Inaccurate" (or something to that effect) booklet. So next time Smokey gets missile-lock on you and you know you weren't speeding, you'll have *some* defense, once you know how radar guns work. Incidentally, does anyone know the author or publisher of "The Ticket Book" which was written by an ex-cop??? I'd like to get my hands on a copy, but My local bookstores can't/won't help me on the basis of such skimpy info. Thanx! Spookfully yours, Gene Traffic court: Where else in the United States are you guilty until proven innocent?
irwin@m.cs.uiuc.edu (01/20/90)
/* Written 12:15 am Jan 18, 1990 by berryh@udel.edu in m.cs.uiuc.edu:sci.electronics */ In article <51058@bbn.COM> jjd@BBN.COM () writes: > However, since we're not talking about radio >waves, it would not be illegal to sell and operate a laser-device >jammer. >>Precisely. I'd just love to see those FCC bastards try to regulate >>optical frequencies. ^^^ ^ | ................................................ >>-- >> John Berryhill >> 143 King William, Newark DE 19711 /* End of text from m.cs.uiuc.edu:sci.electronics */ And why not??? After all, the letters FCC stands for Federal Communications Commission, right? If you can communicate with light (which you can), then they could regulate it, right?? Drats, out foxed again! :-) irwin@m.cs.uiuc.edu Al Irwin Univ of Illinois Dept of Comp Sci
irwin@m.cs.uiuc.edu (01/20/90)
/* Written 9:52 am Jan 19, 1990 by dnewton@carroll1.cc.edu in m.cs.uiuc.edu:sci.electronics */ > We here at Carroll (well, actually, Dave sitting next to me) has solved >the laser speed detector problem: > He suggests a black felt car. Not only would it probably absorb the beam, >but it would feel good too. Nice upholstery, inside and out. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > Large smiley. -- >David L. Newton | uunet!marque!carroll1!dnewton >(414) 524-7343 (work) | dnewton@carroll1.cc.edu >(414) 524-6809 (home) | 100 NE Ave, Waukesha WI 53186 >I'm looking for Tom Brown, Chem. Eng. major at UofIL, Junior. Tell him to call /* End of text from m.cs.uiuc.edu:sci.electronics */ Well, think about this one! Some time back I saw an item on TV about some ding-a-ling in California that sprayed his entire car with glue. Then, he blasted it with grass seed, and let the glue set. Next, he watered the seed and in a week, he had a green car, with inch long hair everywhere. They showed a shot of it on TV, it looked like he had upholstered it with a green carpet. Quite original, I must say! Yup, no one else has one like THAT one! .....and I would like to see it when it came time to mow! Maybe he gets out the sheep shears. irwin@m.cs.uiuc.edu Al Irwin Univ of Illinois Dept of Comp Sci
Ordania-DM@cup.portal.com (Charles K Hughes) (01/20/90)
Brent H. Besler writes: >I posted on rec.autos and sci.electronics about the laser speed measuring devic >e >back in November. I got some info from a Popular Mechanics editor on it. It >is telescopicly aimed. To the best I can determine it uses a GaAs laser diode >around .9 microns in wavelength(just beyond the visible in the IR). It is pret >ty >low power since it is a Class I laser device. The detection apparatus is going > to >have to be pretty sensitive on it, since reflection from a car won't be that hi >gh. >It works on computing succesive distances rather than a doppler effect. It run >s >about $3000, so it is about 3 times more than current radar units. It can't >be used while moving currently since it can't determine the police cars speed >yet. It should be possible to reduce the effective range by using daytime >headlight. They have a high output(halogen particularly) around .9 microns. >The beam is very narrow about 0.2 degress, so a detector will be useless, befor >e >it is too late. > > Brent H. Besler Well, obviously there is a detector race going on... (speed detector versus speed detector detector) and since it isn't likely to stop, the next step will be dull/non-reflective paint and/or a coating that absorbs the specific IR that the laser puts out. :) Charles_K_Hughes @cup.portal.com
kelly@uts.amdahl.com (Kelly Goen) (01/20/90)
In article <4264@rsmas.miami.edu> EAKIN@rsmas.miami.edu writes: >In article <353@egrunix.UUCP>, besler@egrunix.UUCP (Brent Besler) writes: >> >> In general the speedometer in the cop car may be off a couple of MPH, and that >> can make big a big difference with regard to fines, etc. Radar gun aren't >> wired into a cops speedometer. They use a separate radar beam to determine >> the speed of the cop car relative to the ground. well you were only half right the early moving RADARS used a magnet and a hall effect sensor on one of the wheels for a speed pickup... I know because I used (15 years ago) to install these on OK HPD vehicles for a few short months.....the current tech I cant answer with certainty on but I suspect it is still the same....GUNPLEXERS cost 100 times as much as a hall effect sensor and the associated timing electronics... cheers kelly
peggy@pyr.gatech.EDU (Cris Simpson) (01/21/90)
I think the real solution to Laser Cops is to stir up a hysteria among the Great American (and Canadian! Sorry, Henry!) Public about Buck Rogers zapping them with a Laser gun as they drive to the 7-11. Think of the great headlines in the NY Post and USA Today! cris Are we out of beer? Be back in a minute!
urjlew@uncecs.edu (Rostyk Lewyckyj) (01/21/90)
How about coatings that change the wavelength of the reflected light? Or a semireflective half? wavelength thick coating, that would cancell out the reflection by interference? This would seem to be easier than refracting gratings
ferguson@maitai.SRC.Honeywell.COM (Dennis Ferguson) (01/22/90)
In article <19185@bcsaic.UUCP> carroll@bcsaic.UUCP (Jeff Carroll) writes: >In article <8561@nigel.udel.EDU> berryh@udel.edu (John Berryhill) writes: >>Precisely. I'd just love to see those FCC bastards try to regulate >>optical frequencies. > > Which federal agency *is* it that regulates lasers? Isn't it the >FDA? I believe everyone can get into the regulation act. If it's communications, then the FCC is the primary regulator. If it affects airplanes then the FAA regulates it. If it's poses a workplace hazard then OSHA can regulate it. If you ingest it then the FDA can regulate it. The EPA gets to regulate the the byproduct wastes. This sometimes poses some interesting regulatory problems. For example, radio towers over 300 ft tall come under the jurisdiction of the FCC, FAA, EPA, and OSHA. The FCC for potential interference, the FAA as an air traffic hazard, the EPA since radio towers are ugly and despoil the environment, and OSHA since you can get hurt working on one. A laser used for communications would come under the juridiction of the FDA, FCC, FAA (if used near an airport) and possibly the FDA. A very low power laser used as traffic radar would probably come under the jurisdiction of OSHA since the traffic cop could potentially blind himself (zaps the rearview mirror or looks into the beam to see it it's working). Presumably, they wouldn't allow use of a laser powerful enough to blind an oncoming motorist (occasionally, you do get flashblinded by the grocery store lasers). What you need is a stealth car that makes use of tuned optical coatings like the anti laser goggles worn by pilots. If you know the wavelength, you should be able to make an absorbtive coating. Some enterprising person will sell some doped version of polyglycoat (sp?) that prevents rust, renews the finish of older cars, and absorbs those nasty police lasers. Dennis
phil@ingr.com (Phil Johnson) (01/29/90)
In article <1111@khijol.UUCP> erc@khijol.UUCP (Ed Carp, aka Mr. Ed the talking horse...) writes: >In article <8482@ingr.com> phil@ingr.UUCP (Phil Johnson) writes: > >I like the idea of playing ECM with the police, because they've gotten away >from what they're really supposed to be doing, and trying to play all these >sophisticated techno-games with people. Basic law enforcement is where it's >at, not let's-see-how-many-radar-detectors-we-can-find. Police use what ever is necessary to stay ahead of the criminal. >No wonder most criminals are never caught -- the cops are too busy catching >the easy ones. As the local police chief told a friend of mind who asked why the chief was out giving speeding tickets rather than catching the bad guys: "You are one of the bad guys." It is a question of degree of criminality, not of whether or not you are a criminal. -- Philip E. Johnson UUCP: usenet!ingr!b3!sys_7a!phil MY words, VOICE: (205) 772-2497 MY opinion!
greg@sj.ate.slb.com (Greg Wageman) (01/30/90)
Opinions expressed are the responsibility of the author. In article <19185@bcsaic.UUCP> carroll@bcsaic.UUCP (Jeff Carroll) writes: > > Which federal agency *is* it that regulates lasers? Isn't it the >FDA? The FDA would likely only be involved in certifying lasers for use in medical applications. I believe the Department of Health and Human Services (DHHS) regulates lasers in consumer equipment. There probably are other agencies involved in other circumstances. With our wonderful Federal Government beauracracy, it isn't an either-or proposition. Free trade, indeed... "We're lucky we don't get all the government we pay for." Copyright 1990 Greg Wageman DOMAIN: greg@sj.ate.slb.com Schlumberger Technologies UUCP: {uunet,decwrl,amdahl}!sjsca4!greg San Jose, CA 95110-1397 BIX: gwage CIS: 74016,352 GEnie: G.WAGEMAN Permission is granted for reproduction provided this notice is maintained.