laser speed measurement

[fjbauer@dsavm.e-mail.com]

Frank J. Bauer                                                                  
dassault systemes of America     email:fjbauer@dsavm.e-mail.com                 
Subject: laser speed measurement                                                
steve sez:                                                                      
>To get a reading of "0" you would need to be traveling in a circle centered    
>on the REO ... :-)                                                             
when you are "even" (at 90 degrees to the gun) with the REO, it is EXACTLY      
the same AT THAT INSTANT as travelling in a circle with the REO as its center!  

regarding which measurement method used by the speed detector you have two      
choices:                                                                        
- take one measurement and compare frequency broadcast with frequency received  
  (this is doppler)                                                             
- take two measurements and compare times it took to get each reflected         
  signal (and using this to compute distance at those two measurements          
  since we know the speed of laser) divided by the time between measurements.   
not sure what laser uses, but without doppler, one measurement won't do a thing 

frank