Maybe you’ve been on the receiving end of a speeding ticket and though to yourself “Was I really going that fast? Are LIDAR speed guns reliable?”. Unfortunately for speeders, police laser guns, also known as LIDAR speed guns, are incredibly reliable.
So just how does it attain your speed? Essentially, it just measures distance! If you’ve seen someone use a laser rangefinder on the golf course, then you’ve seen the same principles in action.
When the laser gun’s trigger is pressed, the gun very quickly sends out a beam of infrared light. Infrared light is outside of the visible spectrum of light, so the light that the gun emits is invisible, even at night. This infrared beam bounces off of its intended target, a car in this case, and is reflected back to the gun. The gun is timing how long the beam takes to return and, using the speed of light, it determines how far away the car is.
Overall, police LIDAR speed guns work nearly instantaneously (to our perception) and are incredibly accurate. While the guns operate at at least 100 pulses per second, it is estimated that they need only four accurate readings in a row (out of the 100 / 140 / 200 pulses per second) to register a speed reading.Overall, the electronics of the police laser gun are very sophisticated. This process of emitting, receiving, and timing the light happens more than a hundred times per second. That’s right – per second. The rate at which this happens is called the pulse rate, and most guns send out light pulses at a rate of 100-250 pps (pulses per second). Some guns will go up to almost 400pps.
However, environmental factors like rain can decrease a LIDAR speed gun’s reliability. Some police officers will not operate LIDAR or radar in the rain, as the rain droplets can sometimes interfere with the speed readings.
Learn more: How LIDAR Speed Guns Work
Learn how to defend against LIDAR Speed Guns using lasers jammers: How Laser Jammers Work