Laser beams being aimed at airliners?

"Matt Barrow" wrote in message
...

According to a radio show last night, the lasers have been all "green"
except one. Sounds like it might be the laser pens, but do those have
enough
strength to light up a target several thousand feet away?

I have a bunch of high power visible lasers. All except one are Argon or
Argon / Krypton Gas Ion lasers. Argon produces a mixture of blue and green
colours and Krypton generally produces red. They range in output from 3 to
13 watts. The largest is a mixed gas Argon / Krypton. The same laser with
an Argon tube can produce over 20 watts. But they're *big*. The power
supply is the size of a small refrigerator. The head is over 7 feet long
and weighs about 200 lbs. They require 480V AC service and draw about 50
amps. They also require water cooling at a rate of about 3 US gallons per
minute. Hardly portable. And, they cost at least 25K for a decent used
one. A high level of technical expertise is required to operate them. Go
here and look for "Ion Lasers".

http://www.cohr.com/

There are portable systems that can produce power in these ranges though.
More later. I used to have one near the top of the CN Tower in Toronto. It
was a large frame Argon laser and produced about 20 watts. It was focused
on the ground about 3 miles away. I can't remember what the power level was
at the ground. But it was well below 2.5 mw/cm (the safety limit for brief
exposure). However, even at that level it's still bright enough to
temporarily affect night vision after a brief exposure.

The reports indicate a green beam. There are a few types of solid state
lasers that produce green at high power. Here's one of the largest:

http://www.laserfantasy.com/products_i2000.asp

Again, it requires a fair bit of power and water but I've seen portable
versions of them. They're expensive (~50K US) and require technical
expertise to operate. So I don't think they're practical for covert
terrorist activities.

On the small scale, there is a device (I happen to have one) that could be
used as a turbocharged pointer. Go to
http://lasers.mellesgriot.com/default.asp and look at "Diode Pumped Solid
State Lasers". These produce about three watts of green and only draw about
150 watts. They could easily be powered by a small Inverter in an
automobile. Cost is about 12K US new.

Now for a reality check. To actually blind someone at a distance of several
miles is practically impossible. It would require a very high power laser
and sophisticated tracking equipment. Even then, one would have to
intentionally stare at the offending beam for permanent damage to occur.
The same tracking system with a smaller (~2 watt) laser could be used to
make it impossible to carry out the visual portion of an approach. But, and
anyone experience with laser shows will tell you, holding a beam steady at a
distance of miles is really tricky stuff. However, I think that an amateur,
armed with a 3 watt DPSS laser could cause some serious problems just by
sitting in a vehicle at the end of a runway and eyeballing shots at incoming
planes.

Now, in anticipation of the question, here's what it feels like to get
zapped by one of these things at a distance. (It's happened to me many
times.) You will be momentarily blinded. It won't incapacitate your vision
for more than a few seconds, assuming that you blink. You will want to
abort the approach, not because you won't be able to land, but because the
same thing might happen again. Obviously you'll want to alert the police
and FSS or Tower. If the idiot shining the beam leaves it on, you should be
able to see their location. The colour produced by these devices is an odd
sort of green that doesn't occur in nature an is unmistakeable.

Here's some links on laser safety.

http://www.laserist.org/Laserist/Safety.html
http://www.laserfx.com/Science/Science4.html

moo

I have a bunch of high power visible lasers.

Well, Happy Dog, I suspect I speak for most everyone here when I ask:

What the heck do you *do* for a living?

:-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

"Jay Honeck" wrote in message
news:TijCd.614532$wV.146573@attbi_s54...
I have a bunch of high power visible lasers.

Well, Happy Dog, I suspect I speak for most everyone here when I ask:

What the heck do you *do* for a living?


Doesn't involve mutant sea bass, does it?

"Jay Honeck" wrote in
I have a bunch of high power visible lasers.

Well, Happy Dog, I suspect I speak for most everyone here when I ask:

What the heck do you *do* for a living?

www.libertygrand.com
www.eventservices.ca
www.aerobatics.ca
www.bovinesexclub.com

The terrorist thing is just a hobby. :-)

moo

www.bovinesexclub.com

Dude. You've got to update your current events...

The "Kick Ass Karaoke" is, like, so over!

;-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Happy Dog said about all that needs to be said about the topic. These are
unlikely to cause any serious injury. It is just like the mass hysteria
that followed the craze of pointing red LASER pens at people. (a) You are
not going to be blinded by one of these (b) Are you *really* frightened that
somebody is pointing a gun at you? Get over it.

Aviation is cause for a little more concern as even becoming distracted at a
critical moment can lead to or contribute to an accident chain...but will
not likely be the only cause. Sure, perhaps somebody with a military grade
LASER can aim it at you, the light attracts you to look at it (natural
response) and in the few milliseconds that you actually look at it, your eye
balls melt and both you and your co-pilot are blind. Wasn't this also the
topic of a Clancy novel and/or movie?

I also heard a rumor that we tested a weapon like this once. A giant LASER
with a mirror for high speed aiming powered by a huge diesel generator was
driven out onto the battle field and blinded a bunch of the enemy in desert
storm...so the story goes. But this source says they existed and were never
used....

["Laser Weapons. The United States also has developed advanced laser
weapons, which are designed to blind opponents or disable weapons' firing
optics, and are equipped its Army with it.

Rupert Pengelley, technical editor of Jane's Information Group, was quoted
by an Associated Press report as saying that the laser weapons also might
see their first use by US forces in Iraq. The US Army equipped its Bradley
Fighting Vehicles with laser weapons in the 1991 Gulf War, but they were
never used, the report said, quoting sources in the Federation of American
Scientists.

Human Rights Watch urged a ban on laser arms in 1995, calling it
"unnecessarily cruel and injurious." But media quoted Pengelleyas saying
that the US military, which has been developing lasers for roles that
include missile defense and air-ground attacks, believes it "can now use
this in a fitting and legal manner on the battlefield." ]
http://english.people.com.cn/200303/...9_114207.shtml


Guess I had a little to say too...

"Slip'er" wrote in message

Aviation is cause for a little more concern as even becoming distracted at
a
critical moment can lead to or contribute to an accident chain...but will
not likely be the only cause. Sure, perhaps somebody with a military
grade
LASER can aim it at you, the light attracts you to look at it (natural
response) and in the few milliseconds that you actually look at it, your
eye
balls melt and both you and your co-pilot are blind. Wasn't this also the
topic of a Clancy novel and/or movie?

I also heard a rumor that we tested a weapon like this once. A giant
LASER
with a mirror for high speed aiming powered by a huge diesel generator was
driven out onto the battle field and blinded a bunch of the enemy in
desert
storm...so the story goes. But this source says they existed and were
never
used....

Visible light lasers wouldn't work since the targets can just close their
eyes or look away. UV would be more effective since it would fry retinas
before the victims could react. Also, UV lasers are available in extremely
high power ratings.

moo

I've seen pictures of Humvees with lasers mounted on top- seems the idea was
to use them to detonate unexploded ordnance (by heating it up) at a distance
and that sort of thing. Since UXO doesn't move it wasn't a big deal if it
needed a few seconds to reach critical temperature.

I also saw somewhere that there was some design work done to mount a
tactical laser weapon in a turret on the Joint Strike Fighter. The big issue
was what to do with the excess heat. Seems the types of lasers they were
looking at were about 10% efficient, so for every 1,000 watts of light
output, you'd have 9,000 watts of heat. Given the size lasers they were
talking about, they needed a way to pull that heat off or the laser would
melt itself. So of course the engineers thought to use the airplane's fuel
supply as a heat sink. I sure would have loved to been in the room when they
suggested that to the test pilots. "Sure, we'll just cool the 100,000 watt
laser by pouring jet fuel all over it."

-cwk.

"Happy Dog" wrote in message
. ..
"Slip'er" wrote in message


I also heard a rumor that we tested a weapon like this once. A giant
LASER
with a mirror for high speed aiming powered by a huge diesel generator
was
driven out onto the battle field and blinded a bunch of the enemy in
desert
storm...so the story goes. But this source says they existed and were
never
used....

Visible light lasers wouldn't work since the targets can just close their
eyes or look away. UV would be more effective since it would fry retinas
before the victims could react. Also, UV lasers are available in
extremely
high power ratings.

moo

"Colin W Kingsbury" wrote

I've seen pictures of Humvees with lasers mounted on top- seems the idea
was
to use them to detonate unexploded ordnance (by heating it up) at a
distance
and that sort of thing. Since UXO doesn't move it wasn't a big deal if it
needed a few seconds to reach critical temperature.

I also saw somewhere that there was some design work done to mount a
tactical laser weapon in a turret on the Joint Strike Fighter. The big
issue
was what to do with the excess heat. Seems the types of lasers they were
looking at were about 10% efficient, so for every 1,000 watts of light
output, you'd have 9,000 watts of heat. Given the size lasers they were
talking about, they needed a way to pull that heat off or the laser would
melt itself. So of course the engineers thought to use the airplane's fuel
supply as a heat sink. I sure would have loved to been in the room when
they
suggested that to the test pilots. "Sure, we'll just cool the 100,000 watt
laser by pouring jet fuel all over it."

A 1 Kw laser is tremendously powerful. 10% efficency is pretty good. 9 Kw
of heat to sink is no big deal. Several times that would be feasible since
it's only used for very short periods of time. Not sure what it would be
good for though.

moo




-cwk.

"Happy Dog" wrote in message
. ..
"Slip'er" wrote in message


I also heard a rumor that we tested a weapon like this once. A giant
LASER
with a mirror for high speed aiming powered by a huge diesel generator
was
driven out onto the battle field and blinded a bunch of the enemy in
desert
storm...so the story goes. But this source says they existed and were
never
used....

Visible light lasers wouldn't work since the targets can just close their
eyes or look away. UV would be more effective since it would fry retinas
before the victims could react. Also, UV lasers are available in
extremely
high power ratings.

moo