RE: Helicopter Radar

[Thi VanAusdal <tvanausdal@xxxxxxxxxxxxx>]

> >P.S. as good as the V1 is,  it does not track helicopters 
> >overhead....or does it?

> From what I know, helicopters don't radar. They give/get their
information
> either from the ground units or from 1/8-1/4 mile markers on the
pavement...

> Steve Hodson/1988 e28 m20 RIP..

Steve with the vented block hits it on the head ...

Radar works by measuring a Doppler shift, which occurs when
the target is moving towards or away from the instrument.
If the incident angle is NOT 0 degrees, the value read is 
reduced by the cosine of the angle between the trajectories.
This means that at 90 degrees (cos 90 = 0) the measured velocity
of a vehicle on radar is ZERO.  

A helicopter would have to get behind you or ahead of you to get a radar
reading.  At which point you should have slowed down, screaming
"Look, a friggin chopper!" at any and all passengers in your car.

Airbourne :) units must use VASCAR (measure your time across known
landmarks
of known fixed distance) or pace you (not likely or possible) to find
your
speed, and relay that info down to the ground troops.

Or maybe they use a high-powered lens to read your speedometer. :)

 - thi v.

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