"Do you know what a Doppler is?"
"Assuming you're referring to a radar set, it's one that measures changes in the frequency of returned EM radiation in order to determine the relative velocity of the target. The ones used for weather reports generally just measure the difference between the generated frequency and the returned frequency; but the ones traffic cops use measure the difference in the return from both a narrow and wide beam, in order to measure the velocity of the target relative to the background, without being affected by the velocity of the radar gun itself relative to the target. Now go away, and don't come back unless Heather Hudgins wants to get naked with me."
I fucking hate those spots.