Police can use either radar or laser guns to obtain a vehicle’s speed.
If using a radar gun, the radar gun will use one of the below FCC-approved frequencies:
X Band – 10.525 GHz
K Band – 24.150 GHz
Ka Band – 33.4 – 36.0 GHz
Radar can be used either while the police officer is stationary or moving. Radar waves travel a great distance and can be picked up by a radar detector before the officer sees the vehicle.
If using a laser gun, they will use a laser gun tuned to the FDA-approved:
Laser targets one vehicle at a time. There is no advance warning of police laser gun use. The typical targeting range is only 800-1200 feet.
Laser can only be used while the officer is stationary. If an officer targets your vehicle with laser and you do not have laser jammers, he will obtain your speed immediately.