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

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

"Corky Scott" wrote in message
...
Has anyone been following the disturbing (to me anyway) news stories
about airliners approaching to land being hit with laser beams aimed
at the cockpits?

There are several possibilities:

1) There are terrorists out there planning to make airliners crash with
laser beams and the government has warned us in the nick of time.

2) Terrorists read the government warning and thought "What a good idea!"
and are conducting tests.

3) The local airport haters read the government warning and thought "Revenge
at last!" and are trying to shut down airports, hopefully with great loss of
life so they can say "See, I told you so! Airplanes are dangerous and a
hazard to the community and should be banned forever!" The only difference,
of course, between an airport hater and a terrorist is that the airport
hater is not generally associated with Islam or extremist political groups.
Other than that, both are willing to resort to violence and intimidation in
order to achieve their idea of paradise. The news media, law enforcement,
and politicians are too cowardly to call a local soccer mom who doesn't like
airplanes a terrorist, even if she has repeatedly threatened life and
property in public hearings.

4) Kids read the government warnings and thought, "Cool, we can make a plane
crash!" and are zapping planes with their laser pointers.

5) Pilots, alert because of government warnings, are over-reacting to
accidental contact with legitimate (but possibly careless) users of lasers,
including folks who got new telescopes for Christmas.

6) Any combination of the above. Heck, there could even be web sites and
Usenet forums devoted to such things.

Personally, I doubt that there is one single conspiracy run by some
mastermind who is coordinating these attacks. I mean, in any population of
nearly 300 million people, there are bound to be some heavily armed random
nuts out there. Sooner or later one of them is going to build a nuke, and we
can forget all about lasers.

"C J Campbell" writes:

"Corky Scott" wrote:

Has anyone been following the disturbing (to me anyway) news stories
about airliners approaching to land being hit with laser beams aimed
at the cockpits?

There are several possibilities:
[snip]

5) Pilots, alert because of government warnings, are over-reacting to
accidental contact with legitimate (but possibly careless) users of lasers,
including folks who got new telescopes for Christmas.

An argument against the idea that it's a new telescope owner is that
the green laser pens are typically over $100 (vs. maybe $10-15 for
a typical red laser pointer). Also, the green pointers are mostly
used in amateur astronomy by someone knowledgable about the sky,
who (hopefully) has a bit of common sense. (Of course, this doesn't
in any way say that it isn't a newbie; there are people with lots
of money who think an Astro-Physics 8" refractor is just right as a
first telescope, just like people who do their student training in
a Baron because they think a Cessna 150 is for the hoi polloi...)

I do hope that this doesn't lead to DHS outlawing the green laser
pens. I use one in an astronomy program I run with the National Park
Service inside the District of Columbia (in Rock Creek park, under
the flight path that choppers follow to and from the VP's residence
on the Naval Observatory grounds). And yes, I *am* careful to avoid
pointing it anywhere near anyone overflying the area; the program's
been running for over 50 years and I would hate to have it shut down.

Joe Morris

"Joe Morris" wrote in message
...

I do hope that this doesn't lead to DHS outlawing the green laser
pens. I use one in an astronomy program I run with the National Park
Service inside the District of Columbia (in Rock Creek park, under
the flight path that choppers follow to and from the VP's residence
on the Naval Observatory grounds). And yes, I *am* careful to avoid
pointing it anywhere near anyone overflying the area; the program's
been running for over 50 years and I would hate to have it shut down.

I am sure most of us would hate that, too. You never know what the
Department of Homeland Fear will come up with next, though.

Joe Morris wrote:

An argument against the idea that it's a new telescope owner is that
the green laser pens are typically over $100 (vs. maybe $10-15 for
a typical red laser pointer).

Another argument against this is the location of some of these incidents. You
aren't going to see much of the night sky anywhere close to Teterboro, for
example.

George Patterson
The desire for safety stands against every great and noble enterprise.