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Question:  I have a question regarding the working of police radar detectors.
Specifically, how exactly do they work? I understand how they could be
used to determine a vehicle's distance, and thus to determine relative
speed, but how, for instance, is it used successfully at an angle,
especially when the angle is not known.  Or, for that matter, from a
perpendicular perspective.
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Answer 1:  Police radar measures relative speeds not distance (unlike regular
radars which usually measure distance and direction).  If the police
car is moving, its speed is taken into account.  I believe they are
only used to measure approaching and receding speeds (they cannot take
into account angles other than 0 or 180 degrees)
John Hawley
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Answer 2:Well, if they measured from an angle different from 180
degrees they would get a smaller number for the speed,
so if that was still over the speed limit, your real
speed must have been way over the limit.
Arthur Smith
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