Laser beams being aimed at airliners?

"Corky Scott"
A man has been arrested and charged for the recent laser beam being
aimed into a landing airplane's cockpit in New Jersey.

See:
http://www.nj.com/news/ledger/jersey...6903307830.xml

After reading the article, a couple of things are of interest: The
laser is called a "Jasper Laser" and was bought from a company in
Oregon over the internet. The laser was described as cigar sized and
had a range of up to 25,000 feet.

I dunno about that. This guy was a few miles from the plane. The light may
have been distracting but I really doubt it temporarily blinded the pilots.
Really doubt it. It's a weird colour of green though. Reminds me of the
tube used in old photocopiers. I remember people warning me about leaving
the cover open to copy a book. Like it was some kind of death ray. So
maybe they were spooked. It's a L A S E R, after all. Gotta be very
dangerous... At three miles, you could see the light from this thing. But,
unless it could be held steady, which it can't, it wouldn't represent a
threat. It's going to be *way* less bright than a hit from the popular 4K
Xenon publicity searchlights. Sounds like hype. (Like the pilot who claims
to have permanent retina damage from a laser show system.)

le moo

And these are your cites for to back up the statement that there are systems
in place in all metro areas to triangulate gunshots? THey are, on the other
hand, pretty damn good cites to prove you were wrong since they all are
talking about a pilot program taking place in a few high crime locations in
a couple of cities.



"Larry Dighera" wrote in message
...
On Wed, 5 Jan 2005 12:05:22 -0600, "Gig Giacona"
wrote in
::


So the request is still out there. Do you have any cite for your theory
that
there are microphones scattered over metro areas to triangulate gunshots?


http://student-voices.org/news/index.php3?NewsID=10195
April 7, 2004
Police cams to add gunshot detectors

by Fran Spielman, City Hall Reporter
Chicago Sun-Times

Chicago - Big Brother isn't just watching the bad guys in Chicago. By
late summer, he'll be listening as well -- for the sound of gunshots.

Gunshot detection technology -- capable of "triangulating within 20
feet" the location of a shooting -- is being added to 30 surveillance
cameras already in place on high-crime corners and to 50 new cameras
expected to be installed by late summer at undisclosed locations.
...

-----------------------------------------

http://www.usc.edu/uscnews/stories/10810.html
11/30/04
Waiting for the Gun
A USC engineer uses his expertise with nerve cells to create a
surveillance system that can recognize the sound of a nearby gunshot -
and identify the shooter. In a unique pilot program, L.A. and Chicago
will deploy test units in high-crime areas.

-----------------------------------------

http://www.nlectc.org/techbeat/winte...otWinter01.pdf
Until recently, the Los Angeles Sheriff's Department
(LASD) had no idea how many incidents of actual
gunfire occurred near its Century Station, one of the highest
crime areas in Los Angeles County. Some were random
shots fired into the air; others were drive-by shootings.
Some were nothing more than firecrackers or backfiring
cars. Either way, the majority went unreported.
But a new technology may make this lack of reporting a
thing of the past. Although still in the experimental phase,
gunshot detection technologies are showing promise as a
new way to detect and pinpoint the location of gunfire.
Based on acoustic sensing technology, these location
systems consist of sensors or microphones that detect
the sound of gunfire, transmitters that send a "location
message" to the dispatch center, and a computer that
receives and displays the message. When the message
arrives at the police station, the dispatcher can have a
patrol unit respond to the call.
LASD installed a trial system just days before the millennium
New Year's Eve. The department inundated citizens
with information, staging a press conference to brief
everyone from the local weekly newspapers to the major
television networks, national news agencies, and even
the foreign media. Department officials made it clear that
if a citizen fired a weapon, the system would detect it,
and deputies would not hesitate to arrest the shooter. On
December 31, 1999, in a brief 3-hour period, the Century
Station system detected 1,100 incidents of gunfire. ...

------------------------------------------------

http://www.ncjrs.org/txtfiles1/nij/179274.txt
Discussed in this Brief: The findings of two field studies of acoustic
sensing systems designed to detect the sound of a muzzle blast from a
gun and, within seconds of the shot being fired, triangulate within
some margin of error the location from which the shot was fired,
before alerting the police about the gunshot. The research team
examined the effectiveness of Trilon Technology's ShotSpotter
[trademark) system, which the local police department has operated in
Redwood City, California, since early 1996, and the Alliant
Techsystems Inc.'s SECURES [trademark] system, which police instlled
for 2 months in a neighborhood with high levels of random gunfire in
Dallas, Texas, in 1996. ...

-----------------------------------------------

Mo
http://www.shotspotter.com/inthenews.shtml
http://viterbi.usc.edu/news/news/200...22_gunshot.htm
http://www.maximumpda.com/comments.php?id=311_0_1_0_C

In article . com, wrote:

It seems that he was simply stupid and thoughtless. It's doubtful that
he knew that it would "flood the cockpit" with light. People think
lasers will just show a tiny dot even at a great distance.

Previous to his arrest I was thinking that the FBI should put out a
warning that shining lasers into cockpits would result in being charged
with the intent to murder x people (x = however many souls are on
board). But now I'm just shaking my head at his immaturity. He didn't
have the intent to hurt anyone, he was just showing off, not knowing it
was a really bad idea. Something any kid would probably do as well.

I don't believe it "flooded" anything with light. It's 5 mW. That's
0.005 Watt. So it will "flood" your cockpit with a lot less light than
your LED headlight. Which is not to mention the difficulty of hitting
a moving target from thousands of feet away with a hand-held pointer.
Any "flooding" would be very brief. The major problem would be
distraction, and if we're going after everyone distracting someone
operating a vehicle, I think we should lock up the people responsible
for those obnoxious animated roadside signs. Now *there's* an
anti-terrorism action I could endorse without reservation.

I think this is the typical incredible overreaction because "we have to
look like we're protecting the public." You might as well arrest some kids
that were throwing rocks in the river because an ocean liner might go
past.

Note that there's no way to tell whether this guy was involved in the
Citation incident, by the way. But "flooding the cockpit with light"
from a slant range of over a mile away seems like it would require
something with a much higher output. Maybe there's someone out
there with an industrial laser (or more likely, a spotlight).

Mike Beede

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

That's
0.005 Watt. So it will "flood" your cockpit with a lot less light than
your LED headlight.

This may be true but a laser straight out of the box is pretty
focused, and put a simple lens in front of it and you can keep the
beam even tighter. There may not be that many photons involved, but
they are all coming from the same direction, and that does count for
something. (somebody posted about a five digree divergence, the
lasers I've seen are all much tighter than that.)

I don't know whether it counts for the alleged problems, but there is
a nontrivial difference betweem laser light and the diode in your
headband.

Jose
--
Money: What you need when you run out of brains.
for Email, make the obvious change in the address.

On Thu, 06 Jan 2005 03:52:02 GMT, Jose
wrote in ::

There may not be that many photons involved, but
they are all coming from the same direction, and that does count for
something.

If I'm not mistaken, coherent laser light is all in phase. Doesn't
that cause it to have more energy?

"Jose" wrote in message

0.005 Watt. So it will "flood" your cockpit with a lot less light than
your LED headlight.

This may be true but a laser straight out of the box is pretty focused,
and put a simple lens in front of it and you can keep the beam even
tighter.

Not really. You can use a beam telescope to help a bit. But the problem is
more one of diffusion by the atmosphere than divergence.

There may not be that many photons involved, but they are all coming from
the same direction, and that does count for something.

I assume you mean directed at the same point. In this case, light is acting
like a bunch of particles. It would be the same from a flashlight though.

(somebody posted about a five digree divergence, the lasers I've seen are
all much tighter than that.)

Much. 1 millirad


moo

"Larry Dighera" wrote in message
...
On Thu, 06 Jan 2005 03:52:02 GMT, Jose
wrote in ::

There may not be that many photons involved, but
they are all coming from the same direction, and that does count for
something.

If I'm not mistaken, coherent laser light is all in phase. Doesn't
that cause it to have more energy?

No. The energy is measured in watts like any other kind of power source.
In the case of a laser, it's all concentrated into narrow part(s) of the EM
spectrum. An incandescent lamp, for example, creates more IR than visible
light.

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

"Happy Dog" wrote in message
...
I dunno about that. This guy was a few miles from the plane. The light
may
have been distracting but I really doubt it temporarily blinded the
pilots.
Really doubt it. It's a weird colour of green though. Reminds me of the
tube used in old photocopiers. I remember people warning me about leaving
the cover open to copy a book. Like it was some kind of death ray. So
maybe they were spooked. It's a L A S E R, after all. Gotta be very
dangerous...

It didn't bother us when many of us photocopied our faces...or more
importantly, our buttocks.


Matt
---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO