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[IP] more on Jasper Green Lasers: useful tool or terrorist weapon?



------ Forwarded Message
From: "Joseph C. Pistritto" <jcp@xxxxxxxxxxx>
Date: Tue, 04 Jan 2005 16:49:28 -0800 (PST)
To: <dave@xxxxxxxxxx>
Cc: <amberman@xxxxxxxxxxxxx>
Subject: Re: [IP] Jasper Green Lasers: useful tool or terrorist weapon?

I have one of these lasers.  I use it at star parties to point out objects
in the sky. (not airplanes)  There's a *much* more powerful version (mine
is 5mw) available on the Internet that a guy sells for about $700.  That
one's 100mw and is *extremely dangerous* to use without eye protection.

However green lasers are quite popular with amateur astronomers becuase
your eye is much more sensitive at the green wavelength than the red
wavelength used in older laser pointers (so the beam is visible in most
atmospheric conditions). It makes a really good sky pointer because people
can follow the beam.  By the way the green laser is actually an infrared
laser that is frequency doubled (maybe tripled?) to the green frequency
you see.  So its a more complex (and therefore more expensive) device than
a traditional red laser pointer, which is a semiconductor laser lasing in
the red light band.

However it's *incredibly stupid* to point any laser device at an aircraft
in flight.  While its unlikely pilot eye damage would result (From the one
I have, the 100mw definately could do that), you might easily cause the
pilots to miss something important by distracting them with the beam.

By the way, the airplanes out west here that have reported being
illuminated at 8500 feet must be being hit by something else.  The 5mw
type you see on eBay definately wont illuminate an object 2 miles away.
I've tried it on the ground.   3 or 4 thousand feet i'd believe (i've
illuminated clouds up to 2000 feet above me a couple times and seen the
spot in a telescope).  However there is a source of the higher power ones
around and that might be what's happening.   Whoever is doing that is
probably using a telescope to propagate the beam from though, in order to
keep it on target at that kind of range.

People can do lots of dumb things that aren't terrorism though.

   -jcp-



> ------ Forwarded Message
> From: "Dr. A. Michael Berman" <amberman@xxxxxxxxxxxxx>
> Date: Tue, 04 Jan 2005 14:46:45 -0800
> To: <dave@xxxxxxxxxx>
> Subject: RE: [IP] Jasper Green Lasers: useful tool or terrorist weapon?
>
> New Jersey man admits to pointing laser at aircraft
> Last Updated Tue, 04 Jan 2005 15:51:00 EST
> NEWARK, N.J. - Federal authorities in the U.S. have charged a New Jersey
> man
> who caused a safety scare by pointing lasers at aircraft.
> It's the first arrest in connection with a rash of laser-beam incidents
> involving aircraft in late December. Pilots have reported having lasers
> directed at them in Colorado Springs, Cleveland, Washington, Houston and
> Nashville during the Christmas period. All the aircraft landed safely.
> Last week, the FBI and U.S. Homeland Security Department sent out a memo
> warning of terrorist plans to use lasers as weapons, but not necessarily
> in
> the United States.
> * FROM DEC. 31, 2004: FBI probes reports of lasers beamed at cockpits
> <http://www.cbc.ca/story/world/national/2004/12/31/laser-planes041231.html>
> David Banach, 38, was arrested New Year's Eve after a police helicopter
> spotted him playing with the laser on his back porch near Teterboro
> Airport
> in New Jersey. He is expected to appear in court Tuesday afternoon.
> Banach's
> lawyer says her client is not a terrorist and has no ties to terrorist
> organizations.
> On Dec. 29, pilots preparing to land a chartered jet at Teterboro with 13
> people on board reported seeing three green laser beams hit the
> windshield,
> blinding the pilot and co-pilot briefly. Two days later, a helicopter in
> the
> same area reported it was hit by a beam.
> Court documents indicate Banach originally claimed his daughter aimed a
> laser at the helicopter but later admitted he pointed the light beam at
> two
> aircraft, including the helicopter.
> Banach faces charges of interfering with the operator of a mass
> transportation vehicle and making false statements to the FBI.
> Written by CBC News Online staff <http://www.cbc.ca/bios.html>
>
>
>
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