I'm going to "Laser" a pilot.

On 31 Jan 2005 13:37:52 -0800, wrote in
.com::

Those of us on alt.lasers are having several discussions of this same
topic. Our take is that this is a lot of nonsense, possibly with some
ulterior motive on the part of the government. One person wrote a
letter to one of the government agencies involved, and posted the
reply. The government stands by their story that a doctor (notice, one
doctor) found retinal burns on the pilots he examined (laser source
unknown). We still think it's a bunch of nonsense (several of us have
worked around a lot of lasers, and I, for one, have a degree in Laser
Electro-Optic Technology).

Are you referring to the Delta pilot in the story at the link below,
or the military pilots?

http://www.washtimes.com/national/20...1356-3924r.htm

wrote in message

Those of us on alt.lasers are having several discussions of this same
topic. Our take is that this is a lot of nonsense, possibly with some
ulterior motive on the part of the government. One person wrote a
letter to one of the government agencies involved, and posted the
reply. The government stands by their story that a doctor (notice, one
doctor) found retinal burns on the pilots he examined (laser source
unknown). We still think it's a bunch of nonsense (several of us have
worked around a lot of lasers, and I, for one, have a degree in Laser
Electro-Optic Technology).

"Pilots"? More than one? Anyway, I didn't know that there was an alt.laser
so I'll xpost this to there.

How many instances of retinal damage has there been to spectators of laser
entertainment shows? I've never heard of one. Although not legal in the
US, in other countries, laser entertainment systems with output power of
over twenty watts are regularly used directly on audiences. The laser is
"scanned" using fast moving mirrors or put through various types of
diffraction optics. The levels are far lower at any given observer point.
But they're still often well over 5mW.

moo

"Pilots"? More than one?

The letter that one of the members on the laser forum, Skywise,
received from the APSA refers to multiple pilots with retinal burns.
Here's the link to his Web page:

http://www.skywise711.com/lasers/APSA.html

"Anyway, I didn't know that there was an alt.laser"

Technically, it's alt.lasers .
so I'll xpost this to there.

So I see.

wrote in news:1107218116.856975.93780
@c13g2000cwb.googlegroups.com:

"Pilots"? More than one?

The letter that one of the members on the laser forum, Skywise,
received from the APSA refers to multiple pilots with retinal burns.
Here's the link to his Web page:

http://www.skywise711.com/lasers/APSA.html

"Anyway, I didn't know that there was an alt.laser"

Technically, it's alt.lasers .
so I'll xpost this to there.

So I see.

Thanks for pointing these folks to the right place.

Also, the APSA is not a government organization.

My conversations with the president of the APSA have not
shed any light on the situation.

The claim of retinal damage is still anecdotal.

Laser induced retinal damage is also difficult to diagnose.
It takes an opthamologist with experince in laser injuries
to make a proper diagnosis. So far, all I have been told is
that the diagnosis was made by "a physician."

Also, the descriptions of the symptoms reported are
inconsistent with laser injury. The descriptions I have
heard are more consistent with temporary irritation of the
cornea or outer eye and eyelids due to excessive rubbing
or irritation due to dirt or dust.

My calculations show that in at least one incident where
the aircraft was at 8500 feet that it would take a very
powerful laser to cause eye damage at that distance. The
beam simply spreads out too much, even with collimating
optics.

If such powerful lasers were used, they would have been
easily seen by witnesses on the ground. When I asked about
such witnesses, none are known. So either the beam was not
so powerful or there just didn't happen to be anybody
looking at the time.

Then there is the difficulty in tracking the aircraft. In
one incident it is claimed the laser tracked the aircraft
for 15-20 seconds. I own a telescope and I have many times
tried manually tracking a plane to watch it through the
scope. It's difficult at best. The higher the aircraft is
the easier it is due to the slower apparent motion. But the
higher the plane is, the more powerful the laser needs to
be to cause retinal damage.

The only thing that is certain and is indisputible is that
even a small laser can potentially be a hazard to aircraft
operations at critical times such as final approach.

My efforts are currently concentrating on the alleged
retinal damage.

Brian
--
http://www.skywise711.com - Lasers, Seismology, Astronomy

Home of the Seismic FAQ
http://www.skywise711.com/SeismicFAQ/SeismicFAQ.html

Sed quis custodiet ipsos Custodes?

In article ,
T o d d P a t t i s t wrote:

And just for side interest, the LCD screen on my expensive 21" Sun
monitor is polarized exactly wrong, such that you simply can't use it
while wearing polarized sunglasses. The Sun engineers who designed it
knew computers, but not optics.

Another aside - aviation instruments are often designed with
circular polarizers so the brightness doesn't change at any
angle when wearing polarized sunglasses.


Thanks -- interesting, and the sensible way to do it.

In article . com,
wrote:

The letter that one of the members on the laser forum, Skywise,
received from the APSA refers to multiple pilots with retinal burns.
Here's the link to his Web page:

http://www.skywise711.com/lasers/APSA.html


Just for the record, I'm thoroughly familiar with all the technical
evidence and much of the non-technical evidence in one of the cases
mentioned in passing on this web page, involving a U.S. Navy captain who
allegedly suffered eye damage as a result of being lased by a Russian
freighter in the Strait of Juan de Fuca some years ago while he was
photographing the Russian ship from a Canadian military helicopter that
was circling around it. I'm equally thoroughly convinced that he was
not lased by the freighter, in full agreement with the results of a
lengthy and detailed investigation of the incident carried out by the
U.S. Navy, and also the verdict of a civilian jury in a Seattle court in
which he subsequently sued the Russian freight line for the damages he
believes he suffered.

I have little or no knowledge concerning the possible use of
higher-power lasers to cause significant or permanent eye damage in
military conflicts (except to note that, in common with a number of
other potential weapons systems, the military might be inhibited in
fielding such weapons by practical considerations associated with things
like as serious risks of accidental "friendly fire" damage to own side
forces).

As I've noted in an earlier post, however, I've been told by what I
think are reliable sources that there have been at least some instances
of medium-power visible lasers being used for "dazzle" effects on
military pilots in conflict situations. I would also express a
technical opinion that even quite low-power visible lasers, including
red and especially green laser pointers, could produce significant and
potentially dangerous effects on pilots in some limited situations, at
distances which might be in the few thousand foot range.

I have little or no knowledge concerning the possible use of
higher-power lasers to cause significant or permanent eye
damage in military conflicts

In 1994, I was employed by a military sub-contractor as a Laser
Technician II. The clean room was divided in half. On one side was the
team that was building a YAG-based, non-eye-safe, laser range finder. I
was informed that it could only be used in areas where there weren't
likely to be people. The Geneva Convention prohibits the use of
non-eye-safe lasers on the battlefield, I was informed.

On the other side of the clean room, where I worked, was the team that
built the eye-safe, ErCr: Glass laser range finder. It could be used on
the battlefield with enemy forces present, because it was eye-safe. In
fact, the only reason for making that particular range finder was so
our military would not poke out the enemy's eyes with our lasers
whenever we took a distance reading (presumably before our side blew
the enemy's brains out with a canon).

wrote in message news:

The letter that one of the members on the laser forum, Skywise,
received from the APSA refers to multiple pilots with retinal burns.
Here's the link to his Web page:

http://www.skywise711.com/lasers/APSA.html

Idiots. The APSA hype is a poorly written piece of fear-mongering. Even if
they got every other fact correct, until someone produces a pilot with a
real retina injury, they're not to be believed. They can't get medical
records. But such injuries would be aggravated assault or even attempted
murder. There would be an investigation that they could refer to. *That*
would have the real information on any such injuries.

moo

"Skywise"

Laser induced retinal damage is also difficult to diagnose.
It takes an opthamologist with experince in laser injuries
to make a proper diagnosis. So far, all I have been told is
that the diagnosis was made by "a physician."

IIRC, it was recommended that laserists get retina scans before they begin
working with lasers. They're useful in determining if an injury has
occurred.

The only thing that is certain and is indisputible is that
even a small laser can potentially be a hazard to aircraft
operations at critical times such as final approach.

Even that's debateable. (For laser pointers, anyway.)

My efforts are currently concentrating on the alleged
retinal damage.

Post your findings here.

moo

In article . com,
says...
I have little or no knowledge concerning the possible use of
higher-power lasers to cause significant or permanent eye
damage in military conflicts

In 1994, I was employed by a military sub-contractor as a Laser
Technician II. The clean room was divided in half. On one side was the
team that was building a YAG-based, non-eye-safe, laser range finder. I
was informed that it could only be used in areas where there weren't
likely to be people. The Geneva Convention prohibits the use of
non-eye-safe lasers on the battlefield, I was informed.

On the other side of the clean room, where I worked, was the team that
built the eye-safe, ErCr: Glass laser range finder. It could be used on
the battlefield with enemy forces present, because it was eye-safe. In
fact, the only reason for making that particular range finder was so
our military would not poke out the enemy's eyes with our lasers
whenever we took a distance reading (presumably before our side blew
the enemy's brains out with a canon).


The convention mentioned (Protocol IV) does not prohibit non-eye-safe
lasers on the battlefield. It does prohibit the building of specific
use laser devices to intentionally blind people or use an existing
device to intentionally blind people. It does not cover the accidental
blinding of personnel as a result of the legitimate use of a laser
device (ie rangefinding or target designation). In any event there are
only 79 countries that have ratified the protocol (introduced in 1998)
and to date the US is not one of them.