How often does lidar have to be calibrated?

This is done in private and government laboratories in the state. Each fingerboard must be accurate to 1 mph and the radar unit must match the fingerboard with an accuracy of 1 mph. As more and more people try to fight speeding tickets by claiming that police LIDAR guns are not accurate, it is necessary to have a high level of calibration for police speed guns. These speed guns emit a low-power pulsed laser beam that bounces off the target and returns to the barrel sensor.