From: egreen@East.Sun.COM (Ed Green - Pixel Cruncher)
Newsgroups: misc.consumers
Subject: Re: CHP can't use radar?(Was: What radar d
Date: 21 Dec 1992 14:49:59 GMT
Organization: Sun Microsystems, RTP, NC
Distribution: world
Reply-To: egreen@East.Sun.COM
NNTP-Posting-Host: laser.east.sun.com

In article 1683@scott.skidmore.edu, jreiser@scott.skidmore.edu (Jason Reiser... Asleep) writes:

YO, Wake up, Jason!  :^)

>tzs@stein.u.washington.edu (Tim Smith) writes:
>> Here's how the cops claim they do it:
>> 
>> 	They measure how long it takes the aircraft to go between the
>> 	markers, while they observe the car.
>
>Here we go again Leo!
>
>> 	From this, they determine the aircraft ground speed (65 MPH in
>> 	the case I was reading).
>> 
>> 	They note that they are going the same speed as the car, hence
>> 	the car is speeding.
>> 
>> The court says (I use the singular rather than the plural, because I could
>> only find one California appellate case where someone objected to this on
>> the basis of it being a speed trap) that this is NOT a speed trap, because
>> the aircraft is using the marker to measure its own speed, rather than
>> using them to measure the speed of the car.
>
>Well, I'll give this method credit as being the most outrageous way of
>nabbing a speeder that I have heard to date.  

That's CA for ya!

>Besides the fact that
>its primary purpose is to use a loophole in the law, it isn't really a
>possibility.  Sure, a plane could time itself between those two
>points, but consider each of the following problems... 

[problems deleted]

Most of these problems could be alleviated by the cops using the
aircraft's *shadow* to both pace the car, and determine the plane's
ground speed.  The actual altitude, airspeed, direction, blah, blah, of
the plane are thus pretty much moot, the shadow it throws on the ground
is moving at its groundspeed.

>	So now, are you sure that the CHP actually use such a method?

They *claim* they do.  They are legally prohibited from simply timing
the car through a known distance to determine its speed.  I strongly
suspect that is what they *actually* do, and only use the "matched
speeds" BS if challanged in court.

>Seems to me that any reasonable presentable and intelligent person
>could take such a case to court and put the Police Department to
>shame. 

Probably less than 10% of the ticketed motorists ever challenge the
ticket in court, and most of those have some lame excuse like "my
speedometer was broken."  I would guess that anyone with actual
knowledge of both the CA VC and avionics could present a convincing
case against the accuracy of the speed determination.  Whether *that*
does any good or not is completely up to the judge.

A FOAF contested a radar ticket in a CA court.  He (an EE) proved,
using the radar gun manufacturer's own specifications, that it was
physically impossible for the gun to pick up the return from his
motorcycle, which would be swamped by the return off the truck next to
him.  The judge looked bored throughout his presentation, then said,
"radar technology is well understood, and the officer is a trained
professional.  If he says you were doing 70, you were doing 70.  Do you
want to pay the fine or attend traffic school?"  :^(

---
Ed Green, former Ninjaite |I was drinking last night with a biker,
  Ed.Green@East.Sun.COM   |and I showed him a picture of you.  I said,
DoD #0111  (919)460-8302  |"Go on, get to know her, you'll like her!"
 (The Grateful Dead) -->  |It seemed like the least I could do...