As to the "approaching" setting on the radar unit, (I haven't looked at the manual for that specific model), but normally that is for radar units which can also be used while the patrol unit is in motion. The setting then, calculates, the patrol units speed, the target vehicles speed, and displays the differential. But don't quote me on that one...lol
From the user manual:
Q. Will my radar work while my vehicle is moving?
A No, the GHD and SCOUT radar guns are a stationary only models,
so your vehicle should be parked You need to hold the radar
steady while operating it
Funny, although he mentioned it as "approach" mode, in the manual it's actually referred to "towards" mode.
Also noticed these details in the manual under interference sources:
7.2.2 Fan Interference
Fan interference is the most common form of interference that you
are likely to experience It is caused when the radar measures the
speed of the vehicle blower fan Changing the fan speed causes a
proportional change in the display speed
So if they had the heater on in their patrol car it could mess up the readings?? That sounds like a joke.
and,
7.2.7 Scanning
The GHD and SCOUT are designed to be used while attached
to a solid mount or hand-held in a steady position. Moving or
“scanning” the antenna past stationary objects can cause the
system to detect motion Obtaining a speed reading from scanning
will not happen when you properly use the radar
So is this saying that you can't scan or move the radar device or else you'll get inaccurate readings? Funny, because I'd imagine the officer would have had to scan the radar to follow my car through the curve.