 Laser (or lidar, for light detection and ranging) speed guns use a method that relies on the reflection time from narrow pulses emitted from the laser gun. Laser works a lot like ordinary radar, except that it sends out narrow pulses of light rather than broad radio waves. |
 Radar is used to send out radio waves of specific frequencies in a chosen direction. The traveling waves then bounce off objects, including vehicles, and return to the radar gun's receiving unit. When the waves reflect off a moving vehicle, a measurable frequency shift, called a Doppler Shift occurs. The radar gun computer then uses the frequency shift to calculate the speed of the moving vehicle. |
 Mobile speed cameras work by emitting a super high frequency (radar) beam across the road. Any vehicle passing through the beam at a speed which exceeds the pre-set limit, is automatically photographed. Speed cameras can measure the speed of vehicles travelling in either direction. |
 Fixed speed cameras also use a radar to measure vehicle speed. If a vehicle is detected exceeding the speed limit an image of the vehicle is captured along with information about the location, time and alleged speed. |
 Radar Detector Detection (RDD) is a sophisticated, high performance radio frequency receiver tuned specifically to detect radar detectors. It listens for the faint microwave emissions generated by a modern radar detector and delivers an audible and visual response. |