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I have a real uneasy feeling everytime I see one of these guns pointing my way. Can someone please explain how they function and if there is any health risk (eye sight). I used to work at military sites where everyone must wear laser protective goggles during live-laser trainings. So I want to know if these beams pointing in my direction are harmful. Any safety procedures the police must take in using these things?
Not trying to beat them on the road or in court, just want to know if these devices are 100% safe.



[Modified by sg207ptg, 3:43 PM 4-11-2002]
 

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Re: Laser Radar Gun - How it works and any potential health risks (EvilRocco)

They use a real low level laser, shouldnt hurt anyone. I doubt, the way that the government tries to protect everyone these days, that they would allow it to be used the way it is if it was dangerous at all.
They are a lot like the staging lights at a drag strip or the ones that ring a bell when you cross their path, just a little more focused. They just send out a light beam and a lens in the gun reads the reflection of the light at different intervals, then computes how fast the vehicle is approaching.
You can actually confuse these enough to give you time to see them and slow down. They are not supposed to be accurate at night because all the headlights confuse it, it doesnt know which light to read. During the day, driving with a lot of lights on does the same thing, until you get close enough, then it can make the reading, so it will only give you a few seconds to slow down.
These are also the reason most states require front plates, it is the best reflective surface for the light to bounce off of, cops aim for the front plate first when using them. If you dont have something flat on the front of the car, it just reflects the light off into space. So removing your front plate helps protect you from laser as well.
 

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Re: Laser Radar Gun - How it works and any potential health risks (glxdriver)

quote:[HR][/HR]These are also the reason most states require front plates, it is the best reflective surface for the light to bounce off of, cops aim for the front plate first when using them. If you dont have something flat on the front of the car, it just reflects the light off into space. So removing your front plate helps protect you from laser as well.[HR][/HR]​
If I had a front plate, I would bend so it is angular across the horizontal portion of the plate. Theory being that if it got lased, it would scatter uselessly towards the ground or up into the air.
 

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Re: Laser Radar Gun - How it works and any potential health risks (TabulaRasa)

quote:[HR][/HR]These are also the reason most states require front plates, it is the best reflective surface for the light to bounce off of, cops aim for the front plate first when using them. If you dont have something flat on the front of the car, it just reflects the light off into space. So removing your front plate helps protect you from laser as well.
If I had a front plate, I would bend so it is angular across the horizontal portion of the plate. Theory being that if it got lased, it would scatter uselessly towards the ground or up into the air.
[HR][/HR]​
Exactly.
 

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Re: Laser Radar Gun - How it works and any potential health risks (TabulaRasa)

If we are talking about the same radar device, then you guys are mistaken. First of all, I don't really think that it's a laser in the sence that you're thinking about. You could shoot it in your eyes, crotch, ect, and it will not hurt you. (The battaries will, but you shouldn't be messing with those anyway.) Your car lights have nothing to do with it, day or night. They work just fine at night. You could shine a spotlight at the thing and it'll still read you. Whether you have a front plate or not, or if it's bent at whatever angle you choose, makes no difference either. Every car has more than enough target space to get an accurite reading. The light that it's reading isn't the same as your car lights. If we are talking about the same radar, a radar detector won't pick it up either. About the only thing that WILL affect it, and this applies to all speed measuring devices, is an excessive angle. (ie, they can't get your speed if you are at a 90 degree right angle to them...just an example) Just thought you guys should know.
 

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Re: Laser Radar Gun - How it works and any potential health risks (Ro-Bear)

What if... Not that I would do it even if it works, but what if I install a whole bunch of lasers on the front end of my car that shoot off to both sides of the highway at varying angles. Can I confuse a laser speed gun?
 

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Re: Laser Radar Gun - How it works and any potential health risks (boybaha)

I got to use one before, you have to look in the little whole and make sure you see the licenseplace. Otherwise it sucks!
 

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Re: Laser Radar Gun - How it works and any potential health risks (Euro Dude)

Just to clarify and make sure that we are talking about the same speed measuring device, the one you used should've had a gun like shape and if you look at the front of it, where the "lasers" come out of it'll resemble big binoculars sort of. You press the "trigger" and it'll make a noise. There should be something that lights up when you look through that one part. This sounds like this is the one in question. The name of the most commonly used on is "Lite-ar" or something like that. It doesn't use lasers, but...if memory serves, infared (however you spell it) light. The human eye can't see it and as far as I know, it doesn't injure anything. They teach the people useing them to aim for the front lisence plate for an obvious reason...most are "center mass" of the car and if you aim for that and you "miss" you still have the whole front of the car. From what I've seen of that kind of "radar", it's more acurite than the older ones that use actual "lasers".
As far as putting lasers all over your car, if you get a good radar detector it's basically the same thing. Some just detect what is coming your way ie, the waves coming from the radar gun. The higher dollor ones clain to actually send out a "laser" that will interfere with what's coming back to the cops device and he can't get a true reading to pull you over. As long as a radar dectector is legal in your state, you're go to go. Even if you do get pulled over and they say that they have you by radar, regardless of the device, ask to see it. If they don't have it locked in, you're more than likely going to get off. (It could piss the cop off as well, and you'll get a ticket when he was going to let you off.)
 

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Re: Laser Radar Gun - How it works and any potential health risks (Ro-Bear)

I have read about tests on these laser detectors and they were very much affected by light coming off the car. They are looking for light reflections, and when there is a lot of light being reflected/shined at the sensor, it has to filter out all of the false wavelengths before getting an accurate reading. This is why they are not as accurate at night and take longer to get a reading if the car they are reading has a bunch of lights on. It will get you eventually, but hopefully you can see them in time and slow down.
Now the most recent ones may be better, that I dont know, this was a test done a year or two ago on the kind that looks like a gun with a scope on it.
I have also seen the shape of cars cause problems. Some Fords with the front defrosters built into the window would not let them read at all because all the small tiny wires going through the window deflected the light beams all over the place.
 

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Re: Laser Radar Gun - How it works and any potential health risks (glxdriver)

That might be a different thing than this. Never heard of it, but it could be. Unless your useing infrared for headlights, it shouldn't affect it. Your headlights and the "light" that this thing sends out are two completly different thing. Just go up to a cop one night and say that you need to settle an agrument between a friend and most will be more than happy to explain it to you, but....they won't tell you everything, and will probably "embellish" on it quite a bit. Think of it like this: If used at night, the radar in question had trouble getting a proper reading...how would it be used during the daylight?? Don't people drive with their headlights on during the day as well?? And then the sunlight?? And a tiny wire won't divert enough, if it does at all, enough to mess it up. Neither will wrapping you engine in foil or whatever else that you can think of, except what I posted before..and that's not 100%.
 

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Re: Laser Radar Gun - How it works and any potential health risks (to motorists)? (sg207ptg)

Front license plates were required(in the states that use them) before lidar was used, they are there so the car can be indentified from front and back.
Alex
 

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Re: Laser Radar Gun - How it works and any potential health risks (to motorists)? (sg207ptg)

Very interesting topic. http://****************.com/smile/emthup.gif
I don't think you have much to worry about your health due to LIDAR/"laser gun" exposure. You'd more likely experience damage from a careless laser pointer than LIDAR.
I don't have indisputable proof but rather just some knowledge and common sense.
Consider: For damage to occur the laser light would have to hit the light sensing and delicate retina or back of the eye. Before it does, it has to pass the cornea, lens and iris. Think of the eye as a ping pong ball with a hole cut out to let light in. For a focused light beam to reach the inside it needs to be in perfect alignment. Any shift or movement of the eye, person or source would prevent the laser from hitting the back of the eye.
Practically speaking, for damage to the retina to occur the following conditions must exist.
1- The laser must be pointed directly at your eye. Your eye brow or bridge of the nose doesn't count.
2- You must look directly at the beam's source. No, the trooper's car doesn't count.
3- The two previous conditions must exist at the very same time. (Given perfect alignment, I don't know if the beam is even strong enough to damage.)

If you consider the conditions these events must take place, damage from the laser beam is unlikely.
Think of the distance from the gun to your eye and how any movement is amplified over distance. (Ever try to hold a camcorder steady at full zoom or telephoto? Now try to aim at a postage stamp-sized area.) Think that you are more likely to be in a moving vehicle. Think that the last thing you would be looking at is the aperture from which the laser emerges from.
 

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Re: Laser Radar Gun - How it works and any potential health risks

Some articles on LIDAR (and RADAR detection). If you read nothing else, read the article in the first link. Very good read...

LASER LOSES A LEGAL TEST
Excerpt:
quote:[HR][/HR]...This moving-the-gun exercise illustrated a fundamental flaw in the GEICO guns concept. It doesnt measure speedit measures distance. It makes rapid-fire distance measurements 43 of them in a third of a second each time the trigger is pulledand from those changing distances between the gun and the target over time, it calculates speed.
But speed of what? Since the operator cant see where the beam strikes, how can he know what its tracking? What if it isnt tracking anything? What if it merely moves from a far spot to a close spot? Radar doesnt have this shortcoming, Judge Stanton observed, because it measures speed directly, and every part of a car is going the same speed. But if the laser beam is allowed to move from the windshield to the grille, adding about four feet to the change in distance during the one-third-second measurement, then the gun would show a speed about 8 mph too high....[HR][/HR]​

How does your windshield affect your detector
The Great Detector Test

edit: fixed tags


[Modified by Dinosaurius, 1:36 PM 4-12-2002]
 

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Re: Laser Radar Gun - How it works and any potential health risks (Dinosaurius)

That was an interesting article.
quote:[HR][/HR]Think of it like this: If used at night, the radar in question had trouble getting a proper reading...how would it be used during the daylight?? Don't people drive with their headlights on during the day as well?? And then the sunlight?? And a tiny wire won't divert enough, if it does at all, enough to mess it up.[HR][/HR]​
Think of it this way:
You look 1000 feet down the road at a car and shine a light beam at it. The light reflects and you pick it up and boom, got your reading.
Now look 1000 feet downt the road at a car and shine a light beam at it. The car has headlights and fog lights on. Now try to pick out which beam of light it is that you are supposed to be reading. Little harder, car comes a little closer and then you got it. But it took longer to figure it all out.
Now look 1000 feed down the road at a car at night. Shine the light beam at it. Now not only does one car have lights on, but every car does. Figure out which light is the one being reflected and which are just lights, they all blend together that far away. Almost impossible to figure out which one is the correct one.
That is what the laser gun sees. During the day only one light at the end, its his, easy reading. During the day a few lights down the road, can figure it out only takes a second. At night looking down the road, lots of lights all blurred together. Very hard.
As for the little wires, well it is not just one, but tons of little teeny ones almost making a film of metal that you can see through. That is why they can reflect and cause problems.
 

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Re: Laser Radar Gun - How it works and any potential health risks (Dinosaurius)

Only thing I'd correct in your post is the degree to which you would have to look 'directly' at the laser source.
You implied that even looking at the trooper's car wouldn't be close enough. Thats wrong. As long as the laser gun is firing in your direction and you see it at ANY point in your field of vision (peripheral, front, side, corner, whatever) that means the laser is being focused to your retina. Your brain mainly processes things directly in your immediate center of view, but the retina sees LOTS of things all aorund the sides. Seeing the cop car out of the corner of your eye when a laser gun is fired at your car is close enough. Of course, I'm not saying this will cause any health problems, I don't know about that.
And like the previous post says - the laser gun suffers from an built in flaw. A radar gun measures the immediate doppler shift of a radio frequency - measuring the speed of the vehicle in a single instant.
But a laser gun can't do this trick. Whit it does instead is carefully measure the distance to the target twice in a row over a certain time interval. The main problem is that the target can change within that time interval. Say the first measurment reads the distance to the front bumper. Then the trooper's hand moves ever so slightly and the second measurement takes place on the windshield. Depending on the time interval this extra 4 or 5 feet might significantly increase the calculated speed.
 
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