According to the people that make the Lidar systems, their "beam" of laser light is about 36" in diameter at 1000'. So if you are hit with a Lidar system at 1000' yes, the cop is sure it's your car that they are tracking because no car is smaller than 36" wide. However, if they try to track you at 2000', the "beam" is now 72" or 6' in diameter and it is possible that another car could be being targetted other than your car. Especially if the officier is targetting your headlight. (Imagine a circle 6' in diameter and if one edge of that circle is on your headlight, it's possible that another car's headlight could also be in that same 6' circle, especially if one is on a narrow roadway.) In fact, it could be hitting a car in another lane way behind you. So that's why there is the 1000' rule. (Note: it's a rule, not a law. You'd have to make your argument to the judge to win based on the circumstances of your ticket.) So make sure you know exactly where the cop was and where your car was when he said he clocked you. In fact, even at 1000' if the cop says he targeted your headlight, there may be a remote possiblity that there was some overlap by a car in the other lane and slightly behind you. If the cop targets the license plate, then that's dead center of most cars, so it's probably your car. But if your car does not have a front licence plate, they have to target one of the headlights, thus, there is chance of overlap even at 1000'.

In fact, I might even ask the officer how good of a shot they are with their handgun at 1000'. That's almost a quartermile and I don't know of anyone that can group within 3' at 1000' with a handgun. Since the lidar system uses the same general shape of a gun, (They require the shoulder stock for accuracy, but do the cops use it?) there is no way the cop can really say they know that the moment they pressed the trigger it was really on your car. Also the “dot” or "cross hair" isn’t representative of the actual beam of the LIDAR beyond about 150 feet. Considering that its also not in line with the Transmitting lens, there is an additional parallelax error introduced between the site aim and the actual transmission lens of the LIDAR.

Does the officer squeeze a trigger to activate the lidar? If not, how does it know when to start measuring? If the system is "always measuring" then how does the officer know what car is being measured?

The reason I ask is if there are two cars coming side by side toward the officer, and he's "targeting" either one how do we know the lidar is really measuring either one? Since the lidar makes it's measurement in about 1/3 of a second, and since the unit is hand held and not stationary, when the measurement was taken, the unit could have been targeting a car between two cars way behind them.

I say this because I have a visible laser and I know at 100' it's hard to hold the dot on anything smaller than a large box. At 250' it's near impossible to hold the dot on anything less than a refrigerator. So at 500' or 1000', I can't see how anyone could position it with any accuracy to know exactly what the lidar is hitting. I know my dot moves all over the place at 100' (handheld), I can't imagine what it'd be like at 500' or 1000'.

If the officer is targeting the drivers head light... it could be totally missing the car and hitting a car 100-500' behind the alleged target vehicle. With Radar, it picks up the strongest signal. But with light being reflected back, does it do the same thing? How do we know how strong the signal is? For example, hitting a headlight lets say along the top edge at 1000' compared to hitting the flat white front of a semi trailer box at 1500'. I wonder if the signal from a flat white semi's trailer box at 1500' would provide a stronger signal to the gun than a tangential hit on a headlight at 1000'.

Maybe it's an optical illusion, but with my visible laser, if I hit a target box at 30' that is turned at 45 degrees to me, compared to hitting a flat white wall at 60', the flat white wall's reflection is great than the 45 degree boxes reflection. So if "the strongest signal" can't be trusted, and an officer can't group his service firearm at least within a few feet at 1000' firing by hand, how can anyone believe the lidar is going to select the vehicle the cop thinks he's targeting?

These are things I'd like to know.

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1. Valentine 1
2. Escort
3. Bell
   
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• Blinder
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• Antilaser
  
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