junk@ur-tut.UUCP (Jan Vandenbrande) (02/20/86)
... Is it true that "Laser Pulse" devices are being used to measure vehicle's speed for speed enforcement purposes? Instead of using radar frequencies, a laser pulse reflected from the car is used. Naturally, a radar detector will not pick up such a laser pulse. Has anybody heard of such a rumor before? Or has anybody heard of speed enforcement methods other than the ones in use now? (NB. supposedly it's an infrared laser beam) Jan.
rmrin@inuxa.UUCP (D Rickert) (02/24/86)
> ... > Is it true that "Laser Pulse" devices are being used to measure > vehicle's speed for speed enforcement purposes? > Instead of using radar frequencies, a laser pulse reflected from > the car is used. Naturally, a radar detector will not pick up such a > laser pulse. > Has anybody heard of such a rumor before? Or has anybody heard of > speed enforcement methods other than the ones in use now? > (NB. supposedly it's an infrared laser beam) > > Jan. CAR WARS???? -- You are Beautiful, Dick Rickert my manufactured love;- AT&T CPL but it is only Svengali, Indy, IN talking to himself again. Reward is its own virtue!
jim@sivax.UUCP (Jim Bauman) (02/24/86)
> ... > Is it true that "Laser Pulse" devices are being used to measure > vehicle's speed for speed enforcement purposes? > Instead of using radar frequencies, a laser pulse reflected from > the car is used. Naturally, a radar detector will not pick up such a > laser pulse. > Has anybody heard of such a rumor before? Or has anybody heard of > speed enforcement methods other than the ones in use now? > (NB. supposedly it's an infrared laser beam) The Japanese (who else) are working on it, but don't expect to see it here for several years. How could the county mounties justify junking all their KR-11's for the sake of a laser unit? The cost would be horrendous, and all that just to nail people with Escorts and Buzzfusters? Naaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa!
larry@kitty.UUCP (Larry Lippman) (02/25/86)
In article <378@ur-tut.UUCP>, junk@ur-tut.UUCP (Jan Vandenbrande) writes: > Is it true that "Laser Pulse" devices are being used to measure > vehicle's speed for speed enforcement purposes? > Instead of using radar frequencies, a laser pulse reflected from > the car is used. Naturally, a radar detector will not pick up such a > laser pulse. > Has anybody heard of such a rumor before? Or has anybody heard of > speed enforcement methods other than the ones in use now? > (NB. supposedly it's an infrared laser beam) Yes, it's true. About a year ago, I saw an engineering prototype of such a device, which uses an infrared injection laser diode as the light source. In addition, there was an optical sight (with cross-hairs, :-) ) which ALSO had a beam splitter connected to a CCD array video camera - the intention being to record the offending vehicle on videotape for evidentiary purposes. The electronics in the unit provided a superimposed time/date display along with speed AND RANGE for the video recorder. The princples of low-power laser ranging have been well-developed over the last ten years for use in surveying instruments. The use of such designs for speed measurement purposes is almost trivial. The only stumbling block for law enforcement use has been to develop a unit low enough in cost; to be competitive with radar (it will still cost more, though), such a laser unit must cost << $ 5K. A target price for a unit without the video camera is around $ 2K. I can't wait to see the reaction of the general public... ==> Larry Lippman @ Recognition Research Corp., Clarence, New York <== ==> UUCP {decvax|dual|rocksanne|rocksvax|watmath}!sunybcs!kitty!larry <== ==> VOICE 716/741-9185 {rice|shell}!baylor!/ <== ==> FAX 716/741-9635 {G1, G2, G3 modes} duke!ethos!/ <== ==> seismo!/ <== ==> "Have you hugged your cat today?" ihnp4!/ <==
hsu@eneevax.UUCP (Dave Hsu) (02/26/86)
In article <212@sivax.UUCP> jim@sivax.UUCP writes: >> ... >> Is it true that "Laser Pulse" devices are being used to measure >> vehicle's speed for speed enforcement purposes? >> ... >The Japanese (who else) are working on it, but don't expect to see it >here for several years. How could the county mounties justify junking >all their KR-11's for the sake of a laser unit? The cost would be >horrendous, and all that just to nail people with Escorts and Buzzfusters? > >Naaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa! Gee, I wonder what percentage of Escort owners falls into the `Frequent Transgressor' category...(hey look, it was worth it to justify the bucks for a detector, was it not? if you don't amortize the cost of the detector over its lifespan, do you think it's saved you money yet?) :-) -dave -- David Hsu Communication & Signal Processing Lab, EE Department <disclaimer> University of Maryland, College Park, MD 20742 hsu@eneevax.umd.edu {seismo,allegra}!umcp-cs!eneevax!hsu "Godzilla has been spotted in Sector 5!"
fbr@utastro.UUCP (Frank Ray) (03/01/86)
Never fear. If the fuzz are beaming electromagnetic energy at you, it can be detected. Different wavelength, perhaps, different durations, but there will be a market, then, for IR speed trap detectors. It's still line of sight, but with fewer ways to detect with echos. Probably the big question will be whether an IR detector for this purpose will be regulated (and presumably legal under federal interpretation) by the FCC. fbr@utastro.UUCP
tjsmedley@watmum.UUCP (Trevor J. Smedley) (03/03/86)
In article <442@utastro.UUCP> fbr@utastro.UUCP (Frank Ray) writes: >Never fear. If the fuzz are beaming electromagnetic energy at >you, it can be detected. Not necessarily! If the laser beam is only a couple of millimeters wide, then the chances of it hitting the sensor for your dectctor are pretty slim. Trevor J. Smedley University of Waterloo {decvax,allegra,ihnp4,utzoo}!watmum!tjsmedley
rak@packard.UUCP (Richard A. Karhuse) (03/03/86)
Remember there are no FCC restrictions on IR emissions!! -- Gives a whole new meaning to the term "hot rod" (:-) Richard A. Karhuse desoto!rak LC 2N-D14 x4170
john@gcc-milo.ARPA (John Allred) (03/03/86)
In article <416@watmum.UUCP> tjsmedley@watmum.UUCP (Trevor J. Smedley) writes: >If the laser beam is only a couple of millimeters >wide, then the chances of it hitting the sensor for your dectctor are >pretty slim. Very true, Trevor. However, if the beam is only a millimeter wide, that means that the cop must *aim* it at you. That means he *must* see you, and then aim, which translates into a nontrivial time lag, which can be used to slow down. -- John Allred General Computer Company uucp: seismo!harvard!gcc-milo!john
ins_aeas@jhunix.UUCP (Earle A .Sugar) (03/04/86)
> In article <442@utastro.UUCP> fbr@utastro.UUCP (Frank Ray) writes: > >Never fear. If the fuzz are beaming electromagnetic energy at > >you, it can be detected. > > Not necessarily! If the laser beam is only a couple of millimeters > wide, then the chances of it hitting the sensor for your dectctor are > pretty slim. > > Trevor J. Smedley University of Waterloo > > {decvax,allegra,ihnp4,utzoo}!watmum!tjsmedley Not exactly. Don't forget, there is atmosphere between the laser and your car, and that beam will be diffused all over the place. So, a sensitive detector should be able to detect the presence of a specific wavelength of light, although normal background light may make detection impossible because your detector would be constantly going off. -- ______________________________________________________________________________ Earle A. Sugar Disclaimer:"I doubt anyone else here agrees with me." USENET: ...!seismo!umcp-cs!aplvax!aplcen!jhunix!ins_aeas CSNET:ins_aeas@jhunix.csnet ARPA:ins_aeas%jhunix.csnet@csnet-relay.arpa BITNET: INS_BEAS@JHUVMS (as a last resort) "If you don't expect anything, you'll never be dissappointed." or call 301-889-0815 after 6 P.M. EST
junk@ur-tut.UUCP (Jan Vandenbrande) (03/04/86)
..... An issue was raised that when the laserbeam is narrow enough it would be very hard for the detector to catch it. Well first of all it is not certain that the beam will be very narrow. Solid state laser tend to have a larger fan out than the regular kind. I guess that could be corrected but how much? A second, more important issue are the dangers involved with a narrow laserbeam. You don't need alot of power to cause severe eye damage. I don't know whether such a beam would be able to penetrate through the windshield. If it does there could be some interesting legal implications. Jan.
larry@kitty.UUCP (Larry Lippman) (03/05/86)
In article <442@utastro.UUCP>, fbr@utastro.UUCP (Frank Ray) writes: > Never fear. If the fuzz are beaming electromagnetic energy at > you, it can be detected. Different wavelength, perhaps, different > durations, but there will be a market, then, for IR speed trap > detectors. It's still line of sight, but with fewer ways to > detect with echos. How is a detector going to sense a few millimeter diameter spot of IR energy aimed at a random area on a car? Like a bumper, door, grille, etc.? > Probably the big question will be whether > an IR detector for this purpose will be regulated (and presumably > legal under federal interpretation) by the FCC. No way will there be FCC regulation. OSHA, perhaps, just to certify that the energy level is harmless. ==> Larry Lippman @ Recognition Research Corp., Clarence, New York <== ==> UUCP {decvax|dual|rocksanne|rocksvax|watmath}!sunybcs!kitty!larry <== ==> VOICE 716/741-9185 {rice|shell}!baylor!/ <== ==> FAX 716/741-9635 {G1, G2, G3 modes} duke!ethos!/ <== ==> seismo!/ <== ==> "Have you hugged your cat today?" ihnp4!/ <==
abeles@mhuxm.UUCP (J. Abeles (Bellcore, Murray Hill, NJ)) (03/05/86)
>If the laser beam is only a couple of millimeters >wide, then the chances of it hitting the sensor for your dectctor are >pretty slim. The laser beam isn't going to be that narrow. More like a few inches. It depends on whether they are going to use a gas laser or a semiconductor laser, the latter having wider beams. I would have to agree that it will be harder to detect the laser beam than a microwave beam.
jordan@noscvax.UUCP (Martin C. Jordan) (03/11/86)
I have a question concerning the practical implementation of
an IR/visible laser pulse to speed enforcement. Laser radiation will
either be reflected, absorbed, or backscattered at the surface of the
oncoming vehicle. Unless the vehicle is a MACK truck, the reflected
component will be reflected at some angle AWAY from the direction of
arrival. With the "wedge" shape of current sports cars, this is probably
an upward direction. The amount absorbed will vary with paint composition,
but those of us with lots of chrome will absorb little, increasing our
likelihood of detection. Backscatter will also be a function of surface
composition (paint, chrome, bra material, etc.), but should contribute
little to the returned signal. In short, the laser device is like shooting
pool, where the cue ball comes right back at you no matter what the
angle of your bank shot.
Any counters to this hypothesis? If not, I shall sleep easier
knowing Buford T. Justice will be denied his cut of the Star Wars' pie.
Keep on Truckin'
Martin Jordan
'57 CHEVYS ...... FOREVER!!!!!hsu@eneevax.UUCP (Dave Hsu) (03/13/86)
In article <252@noscvax.UUCP> jordan@cod.UUCP (Martin C. Jordan) writes: >little to the returned signal. In short, the laser device is like shooting >pool, where the cue ball comes right back at you no matter what the >angle of your bank shot. > Any counters to this hypothesis? If not, I shall sleep easier >knowing Buford T. Justice will be denied his cut of the Star Wars' pie. > > Martin Jordan Hear that, Buford? Them new-fangled laser things you bought in town don' work 'tall...they's jist gonna bounce up an' hit some bird or somethin. I guess we gotta get rid of these laser sights you bought fer our guns, they won't work too well either. I'd better get on the horn and tell the boys over at the fort the bad news, b'fore Uncle Sam buys any more of the durned things. How y'all ah? -dave ;-) -- David Hsu Communication & Signal Processing Lab, EE Department <disclaimer> University of Maryland, College Park, MD 20742 hsu@eneevax.umd.edu {seismo,allegra}!umcp-cs!eneevax!hsu ARPA n. [acronym for Advanced Research Projects Agency.] An agency of the U.S. Department of Defense established in 1968 to test its defenses against misuse and piracy in the large-scale distributed processing environment. -Stan Kelly-Bootle, "The Devil's DP Dictionary"
west@calgary.UUCP (Darrin West) (03/13/86)
In article <252@noscvax.UUCP>, jordan@noscvax.UUCP (Martin C. Jordan) writes: > > I have a question concerning the practical implementation of > an IR/visible laser pulse to speed enforcement. Laser radiation will > either be reflected, absorbed, or backscattered at the surface of the > oncoming vehicle. ... The amount absorbed will vary with paint composition, > but those of us with lots of chrome will absorb little, increasing our > likelihood of detection. Backscatter will also be a function of surface > composition (paint, chrome, bra material, etc.), but should contribute > little to the returned signal. The reflectivity and absorption of any elecromagnetic radiation is a function of the wavelength of the light used. (visible or not). If a fine enough wavelength is used, it would reflect off the microscopic uneven-ness of the the paint or chrome. The trouble with this is that the smaller the wavelength, the more energy is involved. Going the other way may also get the job done. Bouncing a long wavelength off something is highly successful. It is known as radar. :-) Let us hope they don't use visible light (lasers tend to blind people when used without the proper discretion). If you can sense radar waves, you should be able to sense any other EM wave that is not overpowered by background "noise". All you need is the same device that is in the original sensor. The only problem is where to mount it (them). Keeping a tight beam will likely have the problems mentioned by M Jordan, and will also put a good drain on a battery. Darrin West. CPSC Grad Student.
paul@axiom.UUCP (Paul O`Shaughnessy) (03/13/86)
Regarding the reflection of laser light - unless your car has a true mirror finish, the light tends to be reflected in many directions by irregularities in the surface. Therefore it is theoretically possible for a detector to pick up a reflection from even an oblique surface. Battlefield 'smart' weapons work this way. However, they typically operate with a fairly bright laser, whereas a police laser would need to be toned down drastically to meet safety requirements. This may make it difficult to pick up and separate a reflected signal from background light, particularly if the car does not reflect very well. Also, in keeping with government standard operating procedure, these lasers will be manufactured by the same high tech outfit that sold 'em all the original radar detectors. We'll also know what frequency they lase at, and it might be fun to shine the same color light back at them as you pass by.
fbr@utastro.UUCP (Frank Ray) (03/14/86)
In article <252@noscvax.UUCP>, jordan@noscvax.UUCP (Martin C. Jordan) writes: > > I have a question concerning the practical implementation of > an IR/visible laser pulse to speed enforcement. Laser radiation will > either be reflected, absorbed, or backscattered at the surface of the > oncoming vehicle. Unless the vehicle is a MACK truck, the reflected > component will be reflected at some angle AWAY from the direction of > arrival. > ... > Martin Jordan Now suppose you were going to design an IR speed gun. Wouldn't you want the beam large enough to insure its successful operation in practice, when used by the average traffic cop? True, one could design a system only sharpshooters could use, with a telescopic sight. I suppose the states could also require that each motor vehicle carry a laser reflector on the front, for the sharpshooters to shoot at. Corner cubes would work fine in that regard. Think of the new markets. Some useful things may come out of this laser research, actually, such as automatic highways. "Sorry I'm late getting home, honey. The highway crashed." How about a LASER DETECTOR BRA? Come on you fuzz, shoot me. fbr
larry@kitty.UUCP (Larry Lippman) (03/15/86)
In article <252@noscvax.UUCP>, jordan@noscvax.UUCP (Martin C. Jordan) writes: > I have a question concerning the practical implementation of > an IR/visible laser pulse to speed enforcement. Laser radiation will > either be reflected, absorbed, or backscattered at the surface of the > oncoming vehicle. Unless the vehicle is a MACK truck, the reflected > component will be reflected at some angle AWAY from the direction of > arrival. ... > Any counters to this hypothesis? If not, I shall sleep easier > knowing Buford T. Justice will be denied his cut of the Star Wars' pie. No surface of a motor vehicle will be such a perfect reflector or absorber such that sufficient DETECTABLE modulated IR energy will NOT be returned to the laser device. This statement is based upon the output power/detector sensitivity characteristics of one prototype device which I have seen that has a nominal range of 1,000 meters in clear air. ==> Larry Lippman @ Recognition Research Corp., Clarence, New York <== ==> UUCP {decvax|dual|rocksanne|rocksvax|watmath}!sunybcs!kitty!larry <== ==> VOICE 716/741-9185 {rice|shell}!baylor!/ <== ==> FAX 716/741-9635 {G1, G2, G3 modes} duke!ethos!/ <== ==> seismo!/ <== ==> "Have you hugged your cat today?" ihnp4!/ <==
junk@ur-tut.UUCP (Jan Vandenbrande) (03/16/86)
... How these device really work still seems to be largely unknown. It would seem that either a fairly wide beam is to be used to get any consistent reflection, and/or a very powerull beam is to be used (very in relative terms of course). There are no FCC regulations on IR radiation. So it could be potentially harmfull to the retina. Another issue seems to be where to reflect of. It would seem that an all black car would be virtually immune to laser pulse devices. However, we are judging the color of the car in our visible spectrum. What really matters is what the IR lightbeam considers a reflector and absorber. This sometimes differs significantly from what we see in the visible spectrum. My guess right now is that the windshield could be a good candidate for reflection (but the angle...???) Jan.
stan@clyde.UUCP (Stan King) (03/18/86)
Aren't all cars required to have visible-light corner reflectors installed? Will these also return infra-red light towards the vicinity of the light source? If so, it seems like one of Buford's problems is already solved. -- Stan King phone: 201-386-7433 Bell Labs, Whippany, NJ Cornet: 8+232-7433 room 2A-111 uucp: clyde!stan
fbr@utastro.UUCP (Frank Ray) (03/19/86)
In article <902@clyde.UUCP>, stan@clyde.UUCP (Stan King) writes: > > Aren't all cars required to have visible-light corner reflectors > installed? Will these also return infra-red light towards the > vicinity of the light source? If so, it seems like one of Buford's > problems is already solved. > > Stan King phone: 201-386-7433 So, if one is going to detect EM radiation, a detector near each reflector might be a good place to start. fbr@utastro
daver@felix.UUCP (Dave Richards) (03/21/86)
In article <59@ur-tut.UUCP> junk@ur-tut.UUCP (Jan Vandenbrande) writes: >... > How these device really work still seems to be largely unknown. >It would seem that either a fairly wide beam is to be used to get any >consistent reflection, and/or a very powerull beam is to be used (very >in relative terms of course). There are no FCC regulations on IR radiation. >So it could be potentially harmfull to the retina. > >Jan. Of course there are no FCC regulations on IR radiation, because it is not in the electromagnetic band normally considered to be "radio" frequencies. The agency that monitors laser emissions and such is the B.R.H. (Bureau of Radiological Health). Their safety requirements are quite strict. I used to work for a manufacturer of surgical lasers, and a significant effort went toward ensuring they met B.R.H. standards. Dave
mikel@codas.ATT.UUCP (Mikel Manitius) (03/26/86)
> Of course there are no FCC regulations on IR radiation, because it is not > in the electromagnetic band normally considered to be "radio" frequencies. > The agency that monitors laser emissions and such is the B.R.H. (Bureau > of Radiological Health). Their safety requirements are quite strict. > I used to work for a manufacturer of surgical lasers, and a significant > effort went toward ensuring they met B.R.H. standards. What? The FCC (Federal Communications Commission) regulates COMMUNICATIONS. Radio happens to be one means of communication. For example, electronic communication (such as computers) may be regulated by the FCC, even though they do not use radio frequencies (although the hardware may emit RF). IR may be considered a short range form of communication, and may be under the regulation of the FCC. -- Mikel Manitius @ AT&T-IS Altamonte Springs, FL ...{ihnp4|akgua|bellcore|clyde|koura}!codas!mikel
daver@felix.UUCP (Dave Richards) (03/29/86)
In article <490@codas.ATT.UUCP> version B 2.10.2 9/18/84; site felix.UUCP version B 2.10.2 9/18/84; site codas.ATT.UUCP felix!hplabs!pesnta!peora!codas!mikel mikel@codas.ATT.UUCP (Mikel Manitius) writes: >> Of course there are no FCC regulations on IR radiation, because it is not >> in the electromagnetic band normally considered to be "radio" frequencies. >> The agency that monitors laser emissions and such is the B.R.H. (Bureau >> of Radiological Health). Their safety requirements are quite strict. >> I used to work for a manufacturer of surgical lasers, and a significant >> effort went toward ensuring they met B.R.H. standards. > >What? The FCC (Federal Communications Commission) regulates COMMUNICATIONS. >Radio happens to be one means of communication. For example, electronic >communication (such as computers) may be regulated by the FCC, even though >they do not use radio frequencies (although the hardware may emit RF). >IR may be considered a short range form of communication, and may be >under the regulation of the FCC. >-- > Mikel Manitius @ AT&T-IS Altamonte Springs, FL > ...{ihnp4|akgua|bellcore|clyde|koura}!codas!mikel Okay, so I didn't choose my words carefully enough to be safe from picky people. Fine. Were we talking about communications? No, we were talking about IR used for distance/speed measuring equipment. You find an IR LED or laser that has a certification sticker from the FCC regarding light (not RFI) emissions on it, and I'll give you 50 gold stars which you may stick where you please. Dave