Laser Speed Measuring
Recently, many police departments have added a new sort of speed detector, one that uses light instead of radio waves.
The basic element in a laser speed gun, also called a lidar gun (for light detection and ranging), is concentrated light, or a laser beam of light. Or laser, meaning Light Amplification by Stimulated Emission Radiation
The laser speed measuring device again clocks time vs. distance. Laser measures the time it takes a burst of infrared light to reach a car, bounce off and return back to the starting point. By multiplying this time by the speed of light, the lidar system determines how far away the object is.
Unlike traditional police radar, lidar does not measure change in wave frequency. Instead, it sends out many infrared laser bursts in a short period of time to collect multiple distances. The laser operator looks through an eye piece (scope) on the instrument to view the vehicle. The officers scope will be approximately two times field of view like a 2 times set of binoculars.
The operator then targets the vehicle by placing a red dot on the vehicle within the scope. Typically the officer will put the red dot on the front of the car. The officer then pulls a trigger on the unit, the laser unit sends out a beam of light and records approximately 13 readings within one second of activation by the officer.
The laser compares the distance traveled by the time (Time x Distance) and gives a speed reading. The officer can, by pushing a button on the instrument also receives a measurement of the distance in 1/10 of a metre that the instrument recorded the vehicle speeding at. These guns will take approximately twelve readings in less than half a second, so they are extremely accurate.
With radar the car enters the beam and signals bounce back to the receiver. The officer has to determine which vehicle was the vehicle was speeding. With laser, the operator puts a dot from the scope on the bumper of the car, the officer pulls a trigger and receives a reading instantly.
The officer can pick a car out of a crowd or group as long as he can put the dot from the scope of the laser on the front of the vehicle. With radar the officer has to have line of sight to the vehicle meaning in radar the lead vehicle or the first vehicle entering the beam is usually the speed recorded.
Therefore the laser gives the operator a much more accurate determination of the vehicles speed and gives pin point accuracy of which vehicle is involved.
The distance capabilities for a Laser unit at approx up to one kilometer, normal operating range is approx 200 to 500 metres. The accuracy is 99.9%.
For more information call www.OntarioTrafficTickets.com or www.optech.on.ca |
