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From: Ordania-DM@cup.portal.com (Charles K Hughes)
Newsgroups: sci.electronics
Subject: Re: Bad News- Lasers replace Radar guns
Message-ID: <26126@cup.portal.com>
Date: 20 Jan 90 01:55:38 GMT
References: <7263@lindy.Stanford.EDU> <349@egrunix.UUCP>
Distribution: na
Organization: The Portal System (TM)
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Brent H. Besler writes:
>I posted on rec.autos and sci.electronics about the laser speed measuring devic
>e
>back in November.  I got some info from a Popular Mechanics editor on it.  It
>is telescopicly aimed.  To the best I can determine it uses a GaAs laser diode
>around .9 microns in wavelength(just beyond the visible in the IR).  It is pret
>ty
>low power since it is a Class I laser device.  The detection apparatus is going
> to
>have to be pretty sensitive on it, since reflection from a car won't be that hi
>gh.
>It works on computing succesive distances rather than a doppler effect.  It run
>s
>about $3000, so it is about 3 times more than current radar units.  It can't 
>be used while moving currently since it can't determine the police cars speed
>yet.  It should be possible to reduce the effective range by using daytime
>headlight.  They have a high output(halogen particularly) around .9 microns.  
>The beam is very narrow about 0.2 degress, so a detector will be useless, befor
>e
>it is too late.
>
>							Brent H. Besler

  Well, obviously there is a detector race going on... (speed detector versus
speed detector detector) and since it isn't likely to stop, the next step 
will be dull/non-reflective paint and/or a coating that absorbs the 
specific IR that the laser puts out. :)

Charles_K_Hughes
@cup.portal.com