Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site noscvax.UUCP
Path: utzoo!decvax!ittatc!dcdwest!sdcsvax!noscvax!jordan
From: jordan@noscvax.UUCP (Martin C. Jordan)
Newsgroups: net.auto,net.auto.tech
Subject: Re: Laser Pulse Speed Enforcing
Message-ID: <252@noscvax.UUCP>
Date: Mon, 10-Mar-86 18:15:33 EST
Article-I.D.: noscvax.252
Posted: Mon Mar 10 18:15:33 1986
Date-Received: Tue, 11-Mar-86 08:41:29 EST
References: <378@ur-tut.UUCP> <843@kitty.UUCP> <442@utastro.UUCP> <861@kitty.UUCP>
Reply-To: jordan@cod.UUCP (Martin C. Jordan)
Distribution: na
Organization: Naval Ocean Systems Center, San Diego
Lines: 22
Xref: dcdwest net.auto:7799 net.auto.tech:916


        I have a question concerning the practical implementation of
an IR/visible laser pulse to speed enforcement. Laser radiation will
either be reflected, absorbed, or backscattered at the surface of the 
oncoming vehicle. Unless the vehicle is a MACK truck, the reflected 
component will be reflected at some angle AWAY from the direction of 
arrival. With the "wedge" shape of current sports cars, this is probably
an upward direction. The amount absorbed will vary with paint composition,
but those of us with lots of chrome will absorb little, increasing our
likelihood of detection. Backscatter will also be a function of surface
composition (paint, chrome, bra material, etc.), but should contribute
little to the returned signal. In short, the laser device is like shooting
pool, where the cue ball comes right back at you no matter what the
angle of your bank shot. 
        Any counters to this hypothesis? If not, I shall sleep easier
knowing Buford T. Justice will be denied his cut of the Star Wars' pie.

                                        Keep on Truckin'

                                                Martin Jordan

                      '57 CHEVYS ...... FOREVER!!!!!