From kevina  Sat Oct  7 01:30:26 1995
Received: (kevina@localhost) by clark.net (8.6.12/8.6.5) id BAA02066 for kevina; Sat, 7 Oct 1995 01:30:26 -0400
Path: news.clark.net!rahul.net!a2i!bug.rahul.net!a2i!olivea!spool.mu.edu!howland.reston.ans.net!cs.utexas.edu!bcm.tmc.edu!news.msfc.nasa.gov!pendragon.jsc.nasa.gov!fullfeed!NewsMaster
From: NMA <nma@genie.geis.com>
Newsgroups: rec.autos.driving
Subject: Lasers in Maryland
Date: 3 Oct 1995 20:37:31 GMT
Organization: National Motorists Association
Lines: 51
Message-ID: <44s6ub$qor@fullfeed.msn.fullfeed.com>
NNTP-Posting-Host: nma.msn.fullfeed.com
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 1.22 (Windows; U; 16bit)
Content-Type: text/plain; charset=us-ascii
Content-Length: 1905
Apparently-To: kevina
Status: O
X-Status: 

The state's appellate court has found that the theory of laser speed 
detection devices is valid.  This may likely mean that laser guns will be 
given judicial notice, meaning it will be that much easier for the MD 
police to make drivers pay the driving tax since they will no longer have 
to prove the devices' theories in court.  Radar is like that, you no 
longer have to prove the theory of bouncing radio waves off of things to 
detect speed.

 However, laser has some serious disadvantages (in order of likely 
importance):

 Cost.  More than 2x that of a radar unit.

 Use.  Can't be used while the cop car is moving.  Can't shoot thru a 
windshield.

 Targets.  Motorcycles are darn near impossible to get with a laser.  The
headlight confuses the laser a little, and the small target size takes 
care of the rest of the problem.  Dark colored, aero cars are also hard 
to hit.

 Heat.  Hot (HOT) days make lasers less accurate, apparently the heat 
wafting off of the road surface scatters the beam, plus it adversely 
affects the electronics somehow.

 Sun.  That's right, the ole Sun confuses the laser if it's right on the 
horizon and they're shooting into the sun.  It can't see it's own light.



 We have learned that lasers can be used as vascar devices however.

 Policeman stationed at one point zaps a sign halfway down the road and 
records the distance reading, then does the same to a pole or sign 
farther down the road.  (that's done with the help of the gun's 
electronics)  The only caveat: the distance between the two signs must be 
straight, no hills or curves.

 You get zapped when you cross the first and last point, time is 
computed, distance between the two signs is already known = revenue 
enhancement.




-- 
National Motorists Association      	Join the NMA!
nma@genie.geis.com                  	$29 a year.
http://www.msn.fullfeed.com/nma/    	Sign up online.



From kevina  Sat Oct  7 01:30:32 1995
Received: (kevina@localhost) by clark.net (8.6.12/8.6.5) id BAA02074 for kevina; Sat, 7 Oct 1995 01:30:31 -0400
Path: news.clark.net!rahul.net!a2i!bug.rahul.net!a2i!news.erinet.com!uunet!in1.uu.net!news.sprintlink.net!howland.reston.ans.net!ix.netcom.com!netnews
From: tombell@ix.netcom.com (Tom Bell )
Newsgroups: rec.autos.driving
Subject: Re: Lasers in Maryland
Date: 4 Oct 1995 03:04:38 GMT
Organization: Netcom
Lines: 73
Message-ID: <44stk6$bh6@ixnews3.ix.netcom.com>
References: <44s6ub$qor@fullfeed.msn.fullfeed.com>
NNTP-Posting-Host: ix-atl13-26.ix.netcom.com
X-NETCOM-Date: Tue Oct 03  8:04:38 PM PDT 1995
Content-Type: text
Content-Length: 3012
Apparently-To: kevina
Status: O
X-Status: 

In <44s6ub$qor@fullfeed.msn.fullfeed.com> NMA <nma@genie.geis.com>
writes: 

> However, laser has some serious disadvantages (in order of likely 
>importance):
>
> Use.  Can't be used while the cop car is moving.  Can't shoot thru a 
>windshield.
>

The only effect shooting through the windshield has is on detection
range.  Shooting through glass reduces the effective range of the gun
by 500 ft on average. (It has no effect on the accuracy of the gun!) 
If your state has front license plates, you will probably find the
police will often give up 500 ft. of range in exchange for the comfort
of the patrol car! (The plate alone can be detected at 2500 ft. !!!)

> Targets.  Motorcycles are darn near impossible to get with a laser. 
> The headlight confuses the laser a little, and the small target size
> takes care of the rest of the problem.  Dark colored, aero cars are >
> also hard to hit.
>

My experience has been with the Kustom Signals Pro Laser. Maybe the LTI
20/20 is different, but... I really haven't had any problem clocking
motorcycles!  That big front headlight is an easy target, even if it is
turned on!  Dark, aero cars (with retracted front headlights and no
front license plate) are hard to clock at distances greater than 800
ft.

> Heat.  Hot (HOT) days make lasers less accurate, apparently the heat 
>wafting off of the road surface scatters the beam, plus it adversely 
>affects the electronics somehow.
>

I have used the Pro Laser on 95 Degree F days (with the gun in an air
conditioned van) and had no problem locking on targets over 3000 ft
away. (license plate, going away)  Once again, maybe that's a problem
with the LTI.  I have read about problems occurring whent the gun
overheats though!  I haven't intentionally overheated my gun to see!

> Sun.  That's right, the ole Sun confuses the laser if it's right on
> the horizon and they're shooting into the sun.  It can't see it's own
> light.
>

The receiver on the LIDAR gun is very sensitive and can be damaged if
you point it at the sun.  The owners manuel specifically says not to do
that!  For that reason having the sun low on the horizon is good for
the motorist!


> We have learned that lasers can be used as vascar devices however...
> You get zapped when you cross the first and last point, time is 
>computed, distance between the two signs is already known = revenue 
>enhancement.
>

To the best of my knowledge, that is a feature on the LTI only.  You
don't actually get zapped though.  The police zap two objects with the
laser to record the distance between them.  Then, they sit there and
hit a button to start a timer on the gun when you pass the first object
and hit the button again when you pass the second object.  The gun
knows the distance between the objects and is able to calculate your
velocity.  Nothing is being transmitted while the gun calculates your
speed.... very nasty!


Tom Bell
Taylor-Bell Technologies, Inc.
(Mfg. of Laser-Guard license plate covers)

email: tombell@ix.netcom.com

From kevina  Sat Oct  7 01:30:38 1995
Received: (kevina@localhost) by clark.net (8.6.12/8.6.5) id BAA02092 for kevina; Sat, 7 Oct 1995 01:30:37 -0400
Path: news.clark.net!rahul.net!a2i!bug.rahul.net!a2i!genmagic!sgigate.sgi.com!swrinde!cs.utexas.edu!news.sprintlink.net!simtel!news.kei.com!travelers.mail.cornell.edu!news.tc.cornell.edu!newsserver.sdsc.edu!rosebud.sdsc.edu!jeff
From: jeff@sdsc.edu (Jeff Makey)
Newsgroups: rec.autos.driving
Subject: Re: Lasers in Maryland
Date: 6 Oct 1995 01:35:11 GMT
Organization: Future Procrastinators of America
Lines: 21
Message-ID: <45214f$2ee@rosebud.sdsc.edu>
References: <44s6ub$qor@fullfeed.msn.fullfeed.com>
NNTP-Posting-Host: rosebud.sdsc.edu
Originator: jeff@rosebud.sdsc.edu
Content-Type: text
Content-Length: 1013
Apparently-To: kevina
Status: O
X-Status: 

In article <44s6ub$qor@fullfeed.msn.fullfeed.com>,
NMA  <nma@genie.geis.com> wrote:
>The state's appellate court has found that the theory of laser speed 
>detection devices is valid.

Since the theory *is* valid, this is no real surprise.

I was in Maryland just last week and saw a laser trap on eastbound
I-70 a few miles west of Baltimore.  It was like a typical VASCAR
setup, with the cop parked on the median near the top of a hill
looking across the valley at cars as they crest the opposite hill.
Rather than timing them between the VASCAR lines painted on the road,
however, there was a laser unit set up on a tripod.  As the Maryland
State Police are known to do, the cop's car was maroon in color,
unmarked, and had its trunk lid raised in an effort *not* to look like
a speed trap.  He already had someone pulled over as I drove by.

                             :: Jeff Makey
                                jeff@sdsc.edu

Department of Tautological Pleonasms and Superfluous Redundancies Department

