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Man Attacks Police with Laser
Posted: Tue Aug 01, 2006 9:39 am
by CNF2002
http://www.foxnews.com/story/0,2933,206586,00.html
Wow...I thought this had to be fake but it isn't! A kid points a laser pointer at a helicopter and the authorities say the pilots were blinded and was charged with possession of a weapon.
I've had lasers strike me in a dark theater before and, annoying as it is, it didn't blind me. And they don't have much range...so unless this kid pointed the death star at the helicopter, I don't see how the laser could have blinded them (both!).
Re: Man Attacks Police with Laser
Posted: Tue Aug 01, 2006 12:03 pm
by flynrider
CNF2002 wrote:http://www.foxnews.com/story/0,2933,206586,00.html
Wow...I thought this had to be fake but it isn't! A kid points a laser pointer at a helicopter and the authorities say the pilots were blinded and was charged with possession of a weapon.
I've had lasers strike me in a dark theater before and, annoying as it is, it didn't blind me. And they don't have much range...so unless this kid pointed the death star at the helicopter, I don't see how the laser could have blinded them (both!).
There have already been a few cases of people being arrested for shining a laser pointer at a helicopter. One poor slob was arrested under terrorist laws, when he was just out playing with the pointer with his son. It's stupid to point lasers at other people, but this is a lot of hype about nothing. From a slant range of 1,000 ft. it just looks like a bright sparkle. These laser pointers don't have enough wattage to do any damage at that range. I've had people shine green and red ones at me while flying over the city and I thought it looked kind of cool.
My guess is that cops don't like people shining lasers at their choppers, so they tend to exaggerate the effect. I've read a few scientific papers about what kind of wattage would be required to really use a laser as an aircraft blinding weapon. The short answer is : nothing you'll find at the office supply store will come close.
Posted: Tue Aug 01, 2006 12:06 pm
by jonnythan
It's a green laser.
It's easy to buy a green laser online that's much much brighter than a typical laser pointer (thin 100 times as bright). Green also disturbs night vision much more than red.
"Experts say that a direct shot to the eye from a laser over 15 mW can permanently damage the eye within a fraction of a second."
Here's a place you can buy a 120mw green laser:
http://www.megalaser.com/120mw.htm
Posted: Tue Aug 01, 2006 5:32 pm
by Skel3tor1
That's just special. You'd think they'd complain about spotlights flashing around in the night sky while they were at it, but they still exist.
Posted: Wed Aug 02, 2006 9:06 am
by flynrider
jonnythan wrote:It's a green laser.
It's easy to buy a green laser online that's much much brighter than a typical laser pointer (thin 100 times as bright). Green also disturbs night vision much more than red.
"Experts say that a direct shot to the eye from a laser over 15 mW can permanently damage the eye within a fraction of a second."
Here's a place you can buy a 120mw green laser:
http://www.megalaser.com/120mw.htm
Wattage and distance is what counts. A 15 mW green laser pointer shined in your eye by the person sitting next to you could be a problem. At the distances we're talking about, the beam spread is several meters. For flying aircraft, it's a nuisance, but I'd hardly call it dangerous.
From :
http://www.ilda.wa.org/Laserist/Safety_3.html
Lasers and Airplanes: Common Misperceptions
The wave of reports of US aircraft illuminated by lasers highlights in late 2004 and early 2005 highlights need for the public and US Safety officials to better understand the nature of laser technology. A number of inaccurate statements have been repeated by US government officials and the media regarding the hazard level posed by lasers.
A joint memo by the US Dept. of Homeland Security and FBI, for example, warned that terrorists might use inexpensive, off-the-shelf lasers to blind airline pilots in flight. Safety calculations performed using internationally accepted exposure levels show this is not the case. The energy necessary to cause a permanent eye injury at a distance of 1,500 meters would require in excess of 15 watts of laser power and the use of specialized optics to focus the beam. Such a laser setup would cost upwards of $50,000 and would need a highly skilled operator.
Posted: Wed Aug 02, 2006 9:13 am
by jonnythan
flynrider wrote:A joint memo by the US Dept. of Homeland Security and FBI, for example, warned that terrorists might use inexpensive, off-the-shelf lasers to blind airline pilots in flight. Safety calculations performed using internationally accepted exposure levels show this is not the case. The energy necessary to cause a permanent eye injury at a distance of 1,500 meters would require in excess of 15 watts of laser power and the use of specialized optics to focus the beam. Such a laser setup would cost upwards of $50,000 and would need a highly skilled operator.
Hitting the cockpit of an airliner a mile away is quite a bit different than hitting the cockpit of a news or police helicopter 150 feet away.