I'm going to "Laser" a pilot.

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).

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?

"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

Hi, i'm new to Alt.lasers, so bear with me, i'm unfamiliar with the
setup of this forum, to be honest i find the google forums hard to
negotiate.I usually hang out at CPF, which was linked to here. Any
way, that getting OT.
What i wanted to bring up, was Skyline i read your email exchange with
the APSA, and was very impressed. Is there any way to include the
Amount of the "reflected" beam that would reflected off the cockpit
widows them selves? If not, Would you be able to include a refrence to
this?

Now i know that you guys have probably seen this:
http://www.lumalaser.com/redbaron.htm many times, but it relates to
this topic entirely. I don't know who's side of the debate it works
best for though

Hi, i'm new to Alt.lasers, so bear with me, i'm unfamiliar w=ADith the
setup of this forum, to be honest i find the google forums h=ADard to
negotiate.I usually hang out at CPF, which was linked to her=ADe. Any
way, that getting OT.
What i wanted to bring up, was Skyline i read your email exc=ADhange
with
the APSA, and was very impressed. Is there any way to includ=ADe the
Amount of the "reflected" beam that would reflected off the=AD cockpit
widows them selves? If not, Would you be able to include a r=ADefrence
to
this?


Now i know that you guys have probably seen this:
http://www.lumalaser.com/redbaron.htm many times, but it relates to
this topic entirely. I don't know who's side of the debate i=ADt works
best for though

"DaFiend" wrote in news:1107310913.876953.310020
@o13g2000cwo.googlegroups.com:

Hi, i'm new to Alt.lasers, so bear with me, i'm unfamiliar w*ith the
setup of this forum, to be honest i find the google forums h*ard to
negotiate.I usually hang out at CPF, which was linked to her*e. Any
way, that getting OT.
What i wanted to bring up, was Skyline i read your email exc*hange
with the APSA, and was very impressed. Is there any way to includ*e the
Amount of the "reflected" beam that would reflected off the* cockpit
widows them selves? If not, Would you be able to include a r*efrence
to this?

BTW, it's "Skywise".

The genereal rule of thumb for the reflection off uncoated glass
at normal incidence (that is, not at an angle) is 4% per surface.
Not sure what it would be for the material actually used in
aircraft, but I doubt it's much different. It also will change
according to the angle of incidence, namely more reflection.
There could also be a small effect do to polarization. Different
polarizations reflect differently at shallow angles.

Before including such numbers in my calcs, I'd need real world
figures of reflection for the materials in use and their
dimensions and numebr of layers to be of much use.

But then, I'm not sure it would be worth the effort. Perhaps
other optics experts coudl comment?


Now i know that you guys have probably seen this:
http://www.lumalaser.com/redbaron.htm many times, but it relates to
this topic entirely. I don't know who's side of the debate i*t works
best for though

Oh yeah. We've been all over that. Do remember they were
dealing with a slow moving plane at very low altitude.

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?

my apologies, i was in a bit of a hurry.

Not a very good start.