[s-cars] Blinder Laseerjammer.......real or junk?

[Kirby Smith]

The doppler shift is proportional to the component of velocity along the
laser beam line of sight (LOS).  That means that is equal to the cosine
of the angle between the velocity vector and the ladar gun LOS to the
car.  Unless the gun has a manual correction for this angle, it will
read low.  There is no doppler shift at 90 degrees to the direction of
travel.

kirby

CyberPoet wrote:
>
> Actually, with the laser gun, there is no reason to not read from any
> angle. The doppler effect is still valid as the beam phase-shifts
> against an object and re-emits an IR return. Theoretically, you could
> simply pop by radio shack, buy a couple dozen IR bulbs (remote control
> type) and wire them around the peripheral of your car (at the grill, at
> the top of the windshield, around the bottom of the skirts) in
> permanent "on" status and see what happens <grins>. I doubt they would
> consume much power :)
>
> By the way, Chris, great article. There is a similar piece in a fall
> issue of Bike magazine about the Gatso effect, including interviews
> with various police officials involved and the lease/kick-back
> arrangement for the companies using them. There was also a recent piece
> in an American car magazine about how changing the interval timing for
> an intersection to 5 seconds (four seconds yellow, one second red pause
> in both directions before green) instead of the standard 3 seconds
> eliminates above 75% of all intersection accidents at those
> intersections (and is much more cost-effective than using camera's).
> On a related note: in the late 80's, in Germany, my uncle had a simple
> solution -- every time he got Gatso'd, he shimmy up the pole and rip
> out the film (dark hearted soul he is, may he be paroled soon). It's
> gotten to the point that the Europeans are now putting camera's pointed
> at the Gatso cameras to catch those who tamper with them.
>
> =-= Marc
>
> On Friday, February 21, 2003, at 02:22 PM, James Murray (LMC) wrote:
>
> > I was under the impression that they cannot legally use a speed
> > reading from
> > such extreme angles.  For example, the accuracy of radar is
> > questionable at
> > approx. 90 degrees from the subject's car.  I've never tried to
> > question
> > this in court (or roadside, doah!).  Seems like small town local cops
> > are
> > the worst abusers of this, parking down the alley and zapping you as
> > you
> > cruise by.   Most traps I've rolled through are usually from directly
> > in
> > front, or with the cruiser at a very slight angle to traffic.
>
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