[Mgs] "black plate cars"

[David Breneman]

--- Stephen West-fisher <steve at coastaldatasystems.com> wrote:

> How would that work? Both light and RF travel pretty much at the
> speed of
> light. I would think the very minute delay in creating the proper
> Doppler
> shift and transmitting it would cause the original signal to get to
> the
> camera just before the "doctored" one. Is there any documentation
> of such a device working?

I've never heard of a laser jammer, but most radar jammers
transmit all the time, usually generating a frequency modulated
sweep above and below the carrier frequency of the radar gun.
They're less effective now that many speeding-revenue-dependent
jurisdictions use wideband or sweep-frequency radar, called
Ka-band in the biz.  Radar jammers are illegal in the US because
you're operating a radio transmitter without an FCC license.
Laser jammers are not illegal because they're no more a 
transmitter than a flashlight is.  But like I said, their
effectiveness is dubious.  Here in Washington, the cops do
aim their laser guns at the license plates, which are
retro-reflective and send the pulse right back.  If you
aim at any other part of the car, the beam will scatter
which is why you can detect laser guns over hills and
around corners with a laser-compatible radar detector if
the conditions are right.  I've done so with my Valentine I
many times.



David Breneman         david_breneman at yahoo.com
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