Lidar detector

A lidar detector or laser detector is a passive device designed to detect infrared emissions, especially those of law enforcement agencies' lidar speed detection devices, and warn motorists that their speed is being measured.

A limitation of lidar is that it cannot be used while a police car is in motion, because it requires the operator to actively target each vehicle, whereas traditional radar can be operated while the police officer is driving his car. Other restrictions include a precipitation free environment, as the laser can produce erratic readings from airborne moisture or smoke. Popularity of lidar speed detection is on the rise, though, as costs decline, ease of operation approaches radar, and existing radar equipment reaches its end-of-service life and is rotated out of service.