You may have seen it before: You’re traveling on the interstate and you see a police officer in his car shooting LIDAR out the driver’s side window. Perhaps he has even seen an officer aiming through his windshield or through his side view mirror?
The question is: can law enforcement officers employ LIDAR from inside your car or truck? In short, Yes!
The police laser, whose official name is LIDAR, is an acronym for Light Detection And Ranging. Among the online community of laser jammers, ‘laser’ may be the most widely used term, but LIDAR is just as acceptable. Police laser pistols can seem complicated and daunting, though with some basic familiarity with math along with an example or two, anyone can understand how to strategize and then defend against them.
In general, police laser guns (LIDAR) calculate speed by using infrared light to measure distance a few hundred times (in just a few seconds). The genius of police laser guns, compared to radar guns, is how the laser beam is concentrated in an extremely small area that can only be focused on one car at a time. Officers would like to be able to locate an exact vehicle, and the small beam on the laser gun allows them to do so. Light rays broaden as they travel; they can start out as small as a pin as soon as they come out of the laser gun. Even so, after 1000 feet the beam is about six feet wide, small enough to focus on a single car.
Many LIDAR speed enforcement officers choose to sit perpendicular to the road and shoot oncoming traffic out the driver’s side window. Why would they do that from inside their car? You can find 3 main reasons:
1. Laser guns are heavy!
Although it may not look like it, a good number of laser pistols have heavy, state-of-the-art interiors, which can put pressure on an officer’s hands and arm if they’re shooting for a long time. For this reason, some officers will additionally use a tripod or place the LIDAR unit on top of their car and aim at vehicles from behind the car.
2. LIDAR Guns Must Be Stable
Most people certainly haven’t used police lasers in the past, therefore they don’t understand how tricky it can be to really focus on a car approaching from a fair distance away. To acquire a speed reading, the officer must keep your car or truck aimed for about one second and prevent it from “sweeping” to the sides. Jerky or sweeping movements could give an incorrect speed reading.
3. They are ready to go
The minute a police officer gets a speed reading, he’s got to go chase the speeder! If he is already sitting in the car, he will be able to start it and turn on the red and blue lights. If he is standing outside the vehicle, he had to open his car door, get in, and then get out, resulting in lost time and, quite possibly, a missed ticketing opportunity.
As mentioned above, some police officers shoot the laser gun through their windshield and even reflect it in the rearview mirror of oncoming cars. This will actually generate a velocity reading, but these methods will likely decrease the functionality of the device and many LIDAR weapons companies do not generally support these methods.