[Sca-cooks] [Ocdlapond] Moving Radar in Speeding Stops

[Stefan li Rous]

<<< Oops.  Meant for a different list obviously.

Simon Sinneghe aka Mark H

At 08:37 PM 1/2/2007, I wrote:

> My understanding of the way these things work (subject to being flat
> wrong) is that it determines speed by reference to the ground as well
> as the target vehicle and that any necessary calculations are done
> internally not depending on the officer.
>
> Mark Hendershott  >>>

And I also believe that you are at least partially wrong. :-) You are  
correct in that little depends upon the officer, although aiming at  
the right object, avoiding interfering objects which could affect the  
reading etc. are. But I believe the radar units use the doppler  
effect (the frequency of waves reflected off of a moving object is  
shifted slightly). I'm not sure if the optical guns use a doppler  
effect or something else. Another possible method is using the time  
of flight of several reflected pulses, but that is more subject to  
error, although it may be how the older guns worked.

Mark
Next project, using a radar gun to cook your breakfast... :-)
(To Stefan this would be incomprehensible or a madman's mumblings)
--------
THLord Stefan li Rous    Barony of Bryn Gwlad    Kingdom of Ansteorra
    Mark S. Harris           Austin, Texas           
StefanliRous at austin.rr.com
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