
Originally Posted by
Pixie
....I told him he should read a child's guide to how radar operates and that he was full of shit.....
Most experienced cops, (after a beer at least,) will admit that they have had some "what the fuck??" moments with radar, where their common sense tells them the reading is simply rubbish.
Newer cops just get used to "reading the meter", and as the Stalker is very confidence inspiring they will often trust its reading above their own senses. After a while, they will have observed a few "gliches" and will tend to be more cautious about their interpretation of the reading.
This particular case IMHO is a bit of a gung-ho cop, who doesn't really understand the limitations of his equipment and is determined to "get a result", even if that means a little white lie or exaggeration is required.
Red Mermaid is just "standing up for the team", an admirable but in this case misplaced bit of loyalty.
The facts remain :
The Stalker CANNOT identify its target
The Stalker DOES NOT know how far away its target is
The Stalker ONLY saves the speed of the STRONGEST target regardless of the number of vehicles in the beam.
Its also worthy to consider how the Stalker works, particularly in mobile mode.
The doppler shift signal tells the Stalker three things...
The direction of travel of the target relative to the police car.
The speed of the target relative to the police car.
The speed of the police car
Digital Signal Processing calculates the target speed from these parameters.
The speed of the police car is an important factor. The radar takes a shot at a stationary object (the road in front of the patrol car), to determine the patrol cars speed.
What if the patrol car is doing 20km/hr, in heavy traffic towards the target which is doing 50 km/hr?
The radar will "see" a 70 km/hr doppler shift signal, and will subtract the 20 km/hr patrol car speed to get 50.
But in traffic, the patrol car speed may be wrong. The radar may be looking at the vehicle in front, and assume it has a "0" speed. In this case the radar will overestimate the speed of the target by the patrol car speed.
The cop might notice this. Then again, he might not.
David must play fair with the other kids, even the idiots.
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