Follow Slashdot stories on Twitter

 


Forgot your password?
Close
typodupeerror
×
The Courts Transportation Technology

Chicago Court Throwing Out LIDAR Speeding Tickets 245

Posted by timothy from the should-happen-more-often dept.
bridgeco writes "Chicago Traffic Court Judges have been throwing out speeding cases in which the driver's speed was measured with a LIDAR. Judges are asking for a special 'Frye Hearing' to determine the accuracy of these devices. Many motorists nabbed for speeding by a laser gun, instead of radar, are seeing their tickets thrown out at Chicago's traffic court because of a legal issue that the city's law department has been unable to overcome. Within the past year judges in Cook County Traffic Court in Chicago determined that speeds captured by lidar were not admissible because the devices had not been proven scientifically reliable in an Illinois court, said Jennifer Hoyle, spokeswoman for the law department, which prosecutes most speeding tickets in the city." (Here's some background on LIDAR from Wikipedia.)
This discussion has been archived. No new comments can be posted.

Chicago Court Throwing Out LIDAR Speeding Tickets More

Chicago Court Throwing Out LIDAR Speeding Tickets

Comments Filter:

  • other problem (Score:5, Funny)

    by Anonymous Coward on Tuesday November 10, 2009 @01:22PM (#30048946)

    Another problem with using frickin' lasers is that you have to trust the sharks to use them correctly.

  • link from search (Score:2, Informative)

    by Anonymous Coward

    http://www.chicagotribune.com/news/chi-speeding-tickets-09-nov09,0,7869040.story

  • Name says it all (Score:4, Funny)

    by noidentity ( 188756 ) on Tuesday November 10, 2009 @01:24PM (#30048994)
    With a name like LIDAR, who would doubt the radar's claimed speed?

  • Colonel Tribune (Score:4, Funny)

    by swanzilla ( 1458281 ) on Tuesday November 10, 2009 @01:29PM (#30049074) Homepage
    from the (bonked) link:

    I'm sorry we had to meet under these circumstances, but allow me to introduce myself. I'm Colonel Tribune, the Web ambassador for chicagotribune.com.

    Looks like the Tribune Co. is really embracing the interweb...

    Meantime, I hope I run into you surfing the Web. You can find me on Twitter and Facebook.

    ...I wonder if Colonel Tribune prefers Farmville or Mafia Wars?

    • Colonel Tribune plays Mafia Wars AND Farmville.

      (and we might have a redirect in place before slashdot editors can fix it)...

      On behalf of Colonel Tribune and Interactive Support deep in the heart of Tribune Tower.

    • Re: (Score:2)

      by mishehu ( 712452 )

      ...I wonder if Colonel Tribune prefers Farmville or Mafia Wars?

      Seeing that the Tribune is in Chicago, I'd say Mafia Wars...

  • link is Judge Borked (Score:5, Interesting)

    by HawkinsD ( 267367 ) on Tuesday November 10, 2009 @01:32PM (#30049130)

    The link doesn't work. On the other hand, there's a very nice 404 page. It's funny, friendly, and attempts to be informative.

    Good error handling is something many of us don't always do well.

  • Oh noes news at 11 (Score:5, Insightful)

    by OzPeter ( 195038 ) on Tuesday November 10, 2009 @01:34PM (#30049162)
    [$group] failed to go through [$procedure] to have [$new_technology] legally recognized by [$other_group]. As a result all results recorded by [$group] using [$new_technology] are considered legally suspect by [$other_group].

    • Re: (Score:3, Interesting)

      by mi ( 197448 )

      What's interesting is that the judges work for "Traffic Courts". If in Chicago that is anything like in New York City, then the two groups (cops and judges) are the same — both work for and report to the Executive Branch. The traffic judges aren't real judges — from the Judiciary branch. New York (and some other locales) get away with this, because driving is not a right, but a privilege, and thus the Executive can simply withdraw it — and need not bother convicting the accused in front of

      • Re: (Score:2, Insightful)

        by osu-neko ( 2604 )
        Rivals working for the same boss who hate each other is terribly new and interesting...

        • Re: (Score:2)

          by mi ( 197448 )

          Rivals working for the same boss who hate each other is terribly new and interesting...

          Why are cops and judges rivals?.. FBI and local police are rivals, yes. Fire and Police Departments could be competing (both have ambulances, for example). But police and traffic judges? Their duties don't overlap at all... Maybe, they belong to the same union (though that's unlikely) and have a conflict there, or something... But otherwise, I don't think, they are rivals at all.

      • because driving is not a right, but a privilege

        That's their claim. The trouble with their claim is that a large subset of people literally couldn't survive without it.

        • Re: (Score:3, Insightful)

          by dissy ( 172727 )

          because driving is not a right, but a privilege

          That's their claim. The trouble with their claim is that a large subset of people literally couldn't survive without it.

          While true, I think the point is an even larger subset of people literally won't survive if those whom can't drive properly are allowed to do so anyway...

          • Re:Oh noes news at 11 (Score:5, Interesting)

            by bill_mcgonigle ( 4333 ) * on Tuesday November 10, 2009 @04:29PM (#30051776) Homepage Journal

            While true, I think the point is an even larger subset of people literally won't survive if those whom can't drive properly are allowed to do so anyway...

            Most license suspensions are for not obeying administrative rules, not due to dangerous conduct. Even at that, though, how do we expect Bob, who lives 10 miles from town, to eat if he has to walk, in the middle of Winter to get his food? Would he have been previously banned from riding a horse? Interesting conundrums.

            • Most license suspensions are for not obeying administrative rules

              Mostly, this means not paying fines, or some BS about child support.

              Even at that, though, how do we expect Bob, who lives 10 miles from town, to eat if he has to walk, in the middle of Winter to get his food?

              Good question - not like we have a transit system worth a damn.

              • Re: (Score:2)

                by mi ( 197448 )

                Good question - not like we have a transit system worth a damn.

                That's an off-topic flamebait. Because where we do have a vast transit system — like NYC — the use of it is also a privilege, not a right. Even though you don't need a license to enter subway, the government can stop you at their whim. Most people only realized this recently, when the city started randomly searching riders' belongings: you can refuse to be searched, but then they can refuse to let you into the subway... Because subwa

            • Re:Oh noes news at 11 (Score:4, Insightful)

              by dissy ( 172727 ) on Tuesday November 10, 2009 @05:54PM (#30052968)

              (Quoting you out of order for simplicity. Please, no one take this as an exact quote of parent.)

              Most license suspensions are for not obeying administrative rules, not due to dangerous conduct.

              OK, I admit you got me there.

              License suspension over administration issues is indeed quite bullshit.

              Would he have been previously banned from riding a horse? Interesting conundrums.

              Actually back then no, if you used your horse and wounded or killed someone, they wouldn't need to ban you from riding horses, since you will either get jailed, shot, or ran out of town by a mob.

              Even at that, though, how do we expect Bob, who lives 10 miles from town, to eat if he has to walk, in the middle of Winter to get his food?

              Well, if Bob living 10 miles from down had his license suspended for reckless operation, then the answer is simple. I have no concern on how Bob will continue to live 10 miles from town in the winter without his car, other than the fact I am GLAD he doesn't have a car. He could freeze to death for all his victims would care.

              Now, for the other Bob that lives on the other side of the street from the first Bob, who had his license revoked because when he paid a parking ticket for $35 a week before it was due, the court added a $1 late fee anyways and never told him about it, thus when his license gets suspended for not paying the full amount, then he is screwed...
              Now _that_ guy I feel really bad for.

              The difference is one is consistently death in an SUV form factor, and the other is not.

              Only the former really should have driving rights revoked. Not the later at all.

              Plus I never understood that line of thinking.
              "Well, this person owes us money. I KNOW! Lets revoke his primary means for earning money! That should get us the money we want"

              • Only the former really should have driving rights revoked. Not the later at all.

                Yeah, I totally agree, yet look how they abuse their power. If Bob killed somebody he probably ought to be in prison for that, not merely having his license revoked. A good (and Constitutional in my state) system would have him being a great, penitent, driver by time he got out.

                The trouble is, our governments seem to rapidly converge on the corrupt and capricious. So, if we have to chose to err on one side of the issue, it's p

        • Re: (Score:2)

          by BobMcD ( 601576 )

          http://en.wikipedia.org/wiki/Natural_and_legal_rights [wikipedia.org]

          Its an interesting debate. Personally I fall on the natural rights side more often than not.

          The government may be legally entitled to restrict you from exercising your right to drive, but only in a manner in accordance with respect to the rights of others.

          The other excesses we tolerate are via the social contract. And that contract is getting more and more lopsided with each re-write.

    • Yeah, and in other totally stupid news [$president] was seriously [$event], rushed to [$place] where he's receiving major [$variable]. Pff, wake me up when Firefox 3.6 is out.

  • Yeah, but it is reliable. (Score:4, Informative)

    by captaindomon ( 870655 ) on Tuesday November 10, 2009 @01:40PM (#30049244)
    The point is, LIDAR is reliable, at least as much as RADAR is. This is just a legal snafu, they will throw out enough that there will be incredible pressure to figure out the legal problems, they will figure them out, and then LIDAR tickets will be enforced again. Never underestimate the power of a determined vendor that has been harmed or the importance of sunk costs in equipment for an agency with very limited funding. Nothing to see here, folks. Move along, please.

    • Re:Yeah, but it is reliable. (Score:5, Insightful)

      by cayenne8 ( 626475 ) on Tuesday November 10, 2009 @01:45PM (#30049308) Homepage Journal
      "The point is, LIDAR is reliable, at least as much as RADAR is. This is just a legal snafu, they will throw out enough that there will be incredible pressure to figure out the legal problems, they will figure them out, and then LIDAR tickets will be enforced again. Never underestimate the power of a determined vendor that has been harmed or the importance of sunk costs in equipment for an agency with very limited funding. Nothing to see here, folks. Move along, please."

      Even more than that....NEVER underestimate the greed of the police force to reinstate their favorite method of revenue generation. That's really all this radar/lidar/stop light camera stuff is all about.

      If you were to take all the money generated, and not give it to the cops, but, say, pool it and refund it all the citizens that didn't get a ticket...I'm sure you'd see the enthusiasm by the cops for doing this subside drastically.

      • Re:Yeah, but it is reliable. (Score:5, Interesting)

        by TheCarp ( 96830 ) <sjc@carpaYEATSnet.net minus poet> on Tuesday November 10, 2009 @01:58PM (#30049518) Homepage

        I had always been shocked by the tails of being pulled over for speeding that I hear elsewhere. Compared to what the law says, not only am I a habitual speeder, the general flow of traffic is habitually above the speed limit here. Often by 5-10 in the city and 15 on the highway.

        Despite that, and that I often drive faster than "average", I have been pulled over all of 3 times for speeding in nearly 11 years of driving, and never for less than 20 mph over the limit. Still, never gotten an actual speeding ticket.

        It always boggled me until I heard that my state (MA) does exactly this. The mandate of the police is to keep the traffic moving and safe. NOT to arbitrarily enforce the law for any reason at all times. Since they don't get the ticket money, there is no reason to exceede that mandate.

        Of course, I wonder if its changed. I have noticed that ever since the economy started to nose dive, there have been more and more police, and more and more they are pulling people over, rather than napping by the side of the road. Also, I am not the only one to notice, several other drivers have made the same comment.

        My guess is that they feel the need to suddenly justify their usefulness to fend off budget cuts. Which probably means, that they SHOULD be some of the first ones on the chopping block. If they need to suddenly start enforcing pointless laws to justify their budgets well... can we really call that an improvement? I am in favor of laying off useless state employees if the alternative is to just make them do more pointless work.

        -Steve

        • Welcome to the problem of all law enforcement in the US (some states *cough*virginia*cough* worse than others).

          The police at some point in the last 60 years or so moved from a philosophy of "keeping the peace" to "enforcing the law".

        • Re: (Score:3, Interesting)

          by cellurl ( 906920 ) *
          Hey Steve,

          Fight back by adding some speed limits at Wikispeedia [wikispeedia.org]

          Its us fighting back.

          • Re: (Score:2, Funny)

            by xonar ( 1069832 )
            I find this project very cool, are there any apps available that allow one to enter a speed limit as they see signs, and couple this with your GPS coordinates? I saw an android app here:

            http://handheld.softpedia.com/get/Travel/Wikispeedia-82116.shtml [softpedia.com]

            But I haven't rooted my G1 yet, so I can't install apps not on the market (which it isnt). If this isn't what that particular app does, it would be nice to write one.

        • My guess is that they feel the need to suddenly justify their usefulness to fend off budget cuts. Which probably means, that they SHOULD be some of the first ones on the chopping block.

          You do realize that when these officers are not watching for speeders, they are responding to calls for robberies, murders and rapes..?

          • Re: (Score:2)

            by HogGeek ( 456673 )

            Maybe crime rates would drop if they spent their time looking for "robberies, murders and rapes..", rather the "responding" to them...

            I believe people wouldn't mind "paying the cost", if they "did their job" rather than try to generate revenue...

            "paying the cost" = taxes

            "did their job" = prevent crime by being present and alert (vs. camped out in the middle of the freeway median, chatting with their officer buddy, waiting for the radar to beep at them)

            • Re:Yeah, but it is reliable. (Score:4, Insightful)

              by AshtangiMan ( 684031 ) on Tuesday November 10, 2009 @03:25PM (#30050816)
              you are under the impression (thankfully mistaken) that the police are there to prevent crimes. It's a nice thought, but too slippery a slope.

              • I think that you're the one who is mistaken. Let's take a look at the second part the phrase "law enforcement." To enforce means to ensure observance of laws and rules. [google.com]

                So the job of the police is to make sure that the law is followed. To me this seems like a prevention issue. What most people think is the job of the police, catching bad guys, is actually only in service to prevention of future crime. Catching and punishing criminals helps to ensure that they don't repeat their crimes, and also helps to ensu

                • "Let's take a look at the second part the phrase "law enforcement." "

                  I dunno, I'm pretty sure the motto on the cop cars down here in the city is:

                  To Collect And Serve....

              • The saying is... (Score:3, Funny)

                by swb ( 14022 )

                ...when seconds count, the cops are only minutes away.

          • Re: (Score:2)

            by TheCarp ( 96830 )

            Sure, and I am ok with that. I would RATHER them be responding to those calls than going after speeders.

            However, if there are not enough of those calls to keep them busy.... then I don't think the number of speeders they catch should be used to justify keeping them in a job. Yet, knowing how metrics get used in public policy, I am pretty sure that those numbers will be used along with everything else.

            I have worked my whole career in institutions modeled after public institutions. We use the same sort so fbu

        • Re: (Score:3, Insightful)

          by fulldecent ( 598482 )

          Some police systems have a positive feedback loop where ticket revenue is given back to the police department.

          Must have been a real rocket scientist that didn't see the problem with that setup.

        • Comment removed based on user account deletion

          • Re: (Score:2)

            by TheCarp ( 96830 )

            Understandable. While I do feel for these communities, its also kind of a problem of good enough being the worst possible scenario.

            Since this is the towns only source of income, not only will they refuse to change it, it reduces incentive to fight for the money in other ways. Sure, they could fight an uphill battle to get a bigger share of the tax revenue, or some other way. However, they can choose to lower limits and enforce them without fighting for anything or asking anyones permission.

            So they take the

      • Re:Yeah, but it is reliable. (Score:5, Insightful)

        by Anonymous Coward on Tuesday November 10, 2009 @05:05PM (#30052314)

        If you were to take all the money generated, and not give it to the cops, but, say, pool it and refund it all the citizens that didn't get a ticket...I'm sure you'd see the enthusiasm by the cops for doing this subside drastically.

        I'm a state trooper. My agency gets none of the money for our enforcement.

        It goes to two pools for state and county budgets (unrelated to law enforcement). I suppose you could argue that since we get funded by the state, we're indirectly funding ourselves....but I guarantee our budget hasn't ever been increased because of increased revenue, it goes to whatever pet projects are popular, etc.

        We still get complaints that "it's all about the money". However, I write far more warnings than tickets. Other officers I work with have similar warning/ticket ratios, some more, some less obviously. We've never been pressured to write more tickets.

        Bottom line - At least in my work group/area; we don't give a flying [fill in your fav expletive] about the money. We write tickets when we believe it's justified. If you get one from me (for speeding or otherwise); you probably had it coming. Feel free to resume your rampant paranoia.

        Anonymous Trooper

        P.S. - that was my main point - continue reading for tangential, stream of consciousness type elucidation.

          I have an ongoing friendly debate with a non-cop friend of mine: his philosophy is basically "Let us do whatever the hell we want and don't show up unless we f--- up, to pick up the mess". Sounds great -- limited government and police authority, enforcement only for gross infractions and crashes; I suspect many here would be supportive of that.

        The objections I offer are two. One - see the South Park episode where they fire Officer Barbrady. Two - it's hard to put succinctly, but imagine the things that I and other cops/ EMS/ firefighters see when we come to crash scenes. Dead and dying children, people who look like they belong in a horror movie - I've seen half a torso hanging out a car window.

        Yes, somebody F---ed up.....and many times they run like hell so they don't have to face the consequences. These are the things I think about when I'm stopping people for speed, following too closely, inattentive driving, etc. I'd rather make more stops and issue more tickets and maybe change some behaviors than have to "clean up" those kinds of messes.

        It's not always drunks that kill people, sometimes it's one guy who has to rummage on the floor of his car without looking up for ten seconds at highway speed. Sometimes it's the herd mentality that doesn't see a problem continuing to go 70 in fog so thick you can't see a hundred feet in front of you. Sometimes people get it, sometimes others don't think I'm serious unless they have a $200 ticket in hand and then disregard and keep doing the same thing. Sometimes people thank me and shake my hand when they get a $200 ticket...and not in a make-nice-with-the-cop manner. It would be nice to be able to lower the fees based on attitude, but we have to be consistent...because lawyers exist and you need to show that you do not operate on bias when they ask "Officer, are you sure you didn't issue this ticket because my client is [male/female, ethnicity, color, creed, lifestyle]?

        Many seem to think an officer should know them (I never go this fast / drive like this) and get upset about being stopped or ticketed since (obviously) we should be after the =real= offenders. My last thought - keep in mind we don't know you so we have to act based on the behavior we saw, we don't know if it's typical, or really just a single screw-up.

        Be Safe

    • Re:Yeah, but it is reliable. (Score:4, Interesting)

      by Anonymous Coward on Tuesday November 10, 2009 @01:57PM (#30049498)

      Actually, it is not. LIDAR measures distance, not speed as RADAR does. If you point a LIDAR at a multifactaed object (like say a staionary car) and the operator moves enough to bounce the lazer from the grill to the windshield. A LIDAR will have seen the car 'move' because the distance the lazer went changed. This will not happen with a RADAR because there will be no change in red shift. LIDAR's should not be used in law enforcement.

      • Re:Yeah, but it is reliable. (Score:4, Informative)

        by Bakkster ( 1529253 ) <Bakkster@man.gmail@com> on Tuesday November 10, 2009 @02:27PM (#30049978)

        RADAR isn't always accurate either, as the beam is wider and can't discriminate between different vehicles. It will always give a correct speed, but not necessarily that of the correct target.

        An easy solution would be to capture video of the lazer on the target for every pull. Then compare the data points to the photos of the lazer beam. If there's an excursion, throw the ticket out.

        • Re: (Score:3, Informative)

          by osu-neko ( 2604 )

          RADAR isn't always accurate either, as the beam is wider and can't discriminate between different vehicles. It will always give a correct speed, but not necessarily that of the correct target.

          Yup, if you're in a group of cars, you're safe from RADAR alone, as an old cop friend of mine once told me. They can't really tell what they just got a speed reading of. OTOH, the cops can usually tell when you're speeding without RADAR. They (or at least one of them) use the RADAR to collect objective evidence, not to identify the speeder, they've already done that before they reach for the RADAR gun.

          • Re: (Score:2, Insightful)

            by KC7JHO ( 919247 )
            In Oklahoma an officer is required to be able to determine the speed of an oncoming vehicle with in +-4 mph before graduation from basic police academy. You are correct we know about how fast you are going before we even hit the switch. The Radar usually picks up the largest vehicle in a pack unless it is a radar gun which can be pointed by hand. Never used a LIDAR so while I understand the theory behind it, I cannot comment on it's use or validity.

      • Re: (Score:2)

        by blueg3 ( 192743 )

        That's a qualitative argument. You claim it's possible for the speed reading to be incorrect, due to details of how LIDAR works. There are a lot more details about how the LIDAR gun works. Make the argument quantitative. By how much will the speed reading be incorrect for vehicles that are near or above the speed limit? (Vehicles well below the speed limit are, of course, not of interest.) It's unlikely for any useful measurement device to be perfectly accurate, but putting bounds on its accuracy is an appr

      • Re: (Score:3, Insightful)

        by Mike1024 ( 184871 ) *

        If you can detect the doppler shift on a radio wave (which was created by a sinusoidally oscillating emitter) why couldn't you detect the same doppler shift on a laser signal, if said laser signal was sinusoidally oscillated?

        • This is a guess but we probably don't have the tech to do signal processing at the ~400THz / ~800nm range that LIDAR operates at. After all the ideal antenna length is proportional to the wave length so meter or centimeter wavelengths are manageable, but nanometer antennas would be hard to construct. (I am not a radio engineer. This is only a guess inferred from the physics.)

          • Re: (Score:3, Informative)

            by adolf ( 21054 )

            Just modulate the beam: Turn it off, and back on at a known, sane interval.

            When the interval varies (due to doppler shift), measure the difference in frequency.

            Done.

            No DC-to-daylight processing of gee-whiz THz signals required. The the carrier frequency (the frequency of the laser beam, in this case) is not important for this to work, as long as you can reliably detect its modulation. Many of these parts must already be in use in existing LIDAR systems, so that the machine can discriminate between its ow

      • If you point a LIDAR at a multifactaed object (like say a staionary car) and the operator moves enough to bounce the lazer from the grill to the windshield. A LIDAR will have seen the car 'move' because the distance the lazer went changed.

        It would depend entirely on the integration time of the measurement. If, during the time of measurement, your car moves a distance that is significant compared to the distance from the grill to the windshield then the impact on the result would be insignificant. Assuming a speed of 110km/h, a 1 m distance from the grill to the top of the windshield and a 1 second measurement integration time, the error would be 3%. Standard radar would have a similar uncertainty because of the long wavelength (the fact that

      • Comment removed based on user account deletion

    • Re: (Score:3, Interesting)

      by Hatta ( 162192 )

      I just want to know when they're going to start throwing out cases based on fingerprint evidence. Fingerprinting has not been shown to be scientifically reliable in any court or scientific publication.

    • Re: (Score:3, Informative)

      by poetmatt ( 793785 )

      LIDAR is about as reliable as your imagination. Go research how it works and you'll see, moving objects are not what lidar is for at all. It's just a poor attempt at shoehorning a measurement device that has a monopoly in chicago basically.

  • Fixed Link (Score:2, Informative)

    by internetdarwin ( 669976 )
    Here's a working link to the article: http://www.chicagotribune.com/news/chi-speeding-tickets-09-nov09,0,7869040.story [chicagotribune.com] Note: The forward slash at the end of the link in the summary is what is throwing off chicagotribune.com

  • This still has the sound of defendant intimidation. While it may be true that the judges are throwing out these cases, in every case where the city government asks for a Frye hearing, the procedure intimidates the defendants into just paying the fine rather than trying to stand up against unproven technology.

    • Huh? (Score:2)

      by scheme ( 19778 )

      This still has the sound of defendant intimidation. While it may be true that the judges are throwing out these cases, in every case where the city government asks for a Frye hearing, the procedure intimidates the defendants into just paying the fine rather than trying to stand up against unproven technology.

      What else is the government supposed to do? The admissibility is being challenged by the defendant so the prosecution agrees to a Frye hearing to defend the admissibility of the lidar readings. When the defendents challenge the lidar technology, they're requesting a Frye hearing so the prosecution agreeing to one isn't intimidation.

  • Dead link - here's a CLUE (Score:5, Funny)

    by nsayer ( 86181 ) <nsayer@MENCKENkfu.com minus author> on Tuesday November 10, 2009 @02:40PM (#30050206) Homepage

    I have the solution!

    It was Colonel Tribune, with the forward-slash, on the URL.

  • Radar POP mode (Score:5, Informative)

    by EXrider ( 756168 ) on Tuesday November 10, 2009 @02:52PM (#30050390)
    I would be more concerned with the legality of MPH Industries' radar POP mode [valentine1.com]. In summary, the company is marketing radar guns with a mode that allows officers to obtain speed readings that are at best, inaccurate. Of course, the only place a warning about the inaccuracy of this mode is found, is in the radar's instruction manual. How many police officers do you think read the instruction manuals that accompany their equipment? Reports of people "getting POPped" [valentine1.com] have shown up in WV, OH, GA, NV, NJ, and NY.

    "POP is mode that emits a very brief (67 millisecond) pulse of radar to determine the speed. Its meant to defeat radar detectors. It works because the local oscillator sweep (the "tuner") in most detectors, (especially cheap ones) is too slow to notice this brief pulse. Newer and more expensive detectors have solved this by making a little detour during the sweep to check for POP. It's like flipping through the channels on your TV, but going back to check if your favourite show has started on channel 2 every so often. Except in a radar detector this is happening hundreds of times per second.

    POP can be inaccurate because the electronics in the police radar don't have time enough to stabilize. It's like suddenly jumping on your bathroom scale. The pointer with fluctuate violently until it settles down on the the true reading. With POP it can sometimes indicate an inaccurate speed due to this instability. "
  • The nice thing about LIDAR is that unlike RADAR, I don't need a license to operate a jamming device. After all, it's just an extra "headlight".

  • If they fail, Hoyle said, the prosecutors will seek a state law that explicitly recognizes lidar as scientifically reliable.

    Why not just seek a state law that explicitly recognizes the eyeball judgment by the ticketing officer as scientifically reliable?

Slashdot Top Deals

In the future, you're going to get computers as prizes in breakfast cereals. You'll throw them out because your house will be littered with them.

Close