Laser targets Airlines in Nashville

Fox17News -Nashville (article not posted yet) ^ | Self | Self

[babygene]

"These lasers should be outlawed right away"

Nope... These 4.99mw green lasers are limited to that power specifically because at that power they DO NOT do damage to the human eye. They don't do damage even from across the room, much less a mile away (because of the divergence of the beam)

There are many semiconductor lasers available today that are much more dangerous that are in the IR spectrum, where the power in measured in watts, not milliwatts. These IR lasers are invisible to the human eye, and will permanently blind you is a few milliseconds. For that matter, a 2 watt IR laser will catch paper on fire in a second or two.

Anyone who is inappropriately playing with a green laser pointer is doing just that: "playing" It makes a good news story, but that's about it.

A serious terrorist would find something more appropriate for the task at hand.

[Hunble]

There are many semiconductor lasers available today that are much more dangerous that are in the IR spectrum, where the power in measured in watts, not milliwatts. These IR lasers are invisible to the human eye, and will permanently blind you is a few milliseconds.

I can testify to the dangers of an IR laser. After years of working with YAG lasers with the Army, I caught a reflection and received a tiny burn spot in my eye. Since an IR laser is invisible, I did not know it had happened until much later.

Today, I can only detect the burn spot when viewing a white wall. Other than that, it has not been a problem.

However, I learned a very valuable lesson about the dangers of IR lasers.

[babygene]

"Here's a video of one burning a hole (!) in a plastic cup from four feet away."

What is shown in your video is not a laser pointer. The laser shown in your flick is a multi-watt laser. Instead of 100 bucks, try a couple thousand.

[babygene]

"What DO retro reflectors look like, anyway? 3 flat mirrors at right angles to each other or what?"

Close... It's a corner prism. 1/2 of a cube of glass cut corner to corner and polished.

[Hunble]

While in the Army, my group pioneered the development of 1.54 micron eye-safe lasers. This wavelength is rather unique, since it can not penetrate the aquas-fluid inside the eyeball.

We developed a mega-watt 1.54 micron laser for probing the atmosphere, and I would personally demonstrate it's safety.

With a large group of officers standing around, I would fire the laser into a piece of black plastic. You could hear a large pop, and I would then show them the hole which was burned into the plastic.

I would then aim the laser directly into my eye and fire it...

Although they could hear the audible pop when the laser fired, nothing would happened to me!

Dog and pony shows like that are always fun. However, it was an important demonstration as to why 1.54 micron laser development was important for the safety of military personnel.

P.S. The laser could not penetrate the aquas-fluid inside of my eye and cause any damage, however, it would cause heat inside of the eye and give me a major head-ache! I never mentioned that little annoyance.

[babygene]

Interesting... What you are obviously aware of, though many on this forum don't seem to grasp is that it is extremely difficult to target anything 3 miles away without some sort of targeting system.

I have a laser sight on my handgun, and it's VERY default to even get the dot on the target 300 feet away. Imagine if the target were moving a couple of hundred miles per hour three miles away.

You may get lucky and get a flash of light in the cockpit window, but even if you had a powerfull laser, you would do no damage.

[Hunble]

The key words are "flash of light."

You can move your laser sight at random, and it will occasionally flash upon the target.

Now a steady illumination, lasting over a minute, would be a totally different matter!

[Hunble]

How to have fun at an Air Force target range:

1) Connect a laser detector to your modulated laser.

2) Place the laser detector on the target.

3) Point your modulated laser where you would like the missiles to hit.

4) Meet the Air Force pilots at the local bar that evening and watch their sad faces, since every one of their missiles missed the target that day.

5) Deny everything!

[babygene]

I understand how this could work part of the time, but wouldn't the plane then just see two targets and have to select one?

How would you keep the pilots from seeing the original target?

[Aeronaut]

[Hunble]

How would you keep the pilots from seeing the original target?

The laser guided missile would simply target the brighter illuminated target.

Once the missile is released from the aircraft, the pilot or weapons officer could only watch.

Since I had full control of what target was illuminated, the missile went for the target which I had designated with the brighter laser.

Exactly how this was performed, is obviously classified.

[traumer]

Would it be a CO2 laser or a solid state laser ?
Can any of them operate in the green spectrum ?

[Hunble]

Would it be a CO2 laser or a solid state laser?

A CO2 laser uses Carbon Dioxide as the lasing medium. It is the most powerful commercial laser available, and is often used to cut metal. It operates in the IR spectrum and is invisible to the human eye.

A solid state laser is similar to a LED, which is used in many home applications. For instance, you CD or DVD player has a solid state laser inside of it, for scanning the rotating disks.

Today, technology has produces some fairly high-powered solid state lasers at reduced cost.

[Hunble]

Can any of them operate in the green spectrum?

Yes, solid state lasers are produced that operate in the green spectrum.

This specific green laser can be purchased for $189.00

[Caipirabob]

How easy or difficult is it to buy a green laser? If it's not difficult, could very well be copycats.

The real concern is that they are apparently able to "track" a moving aircraft at 300-500 mph. ~175-250 mph coming in for a landing at 6 miles. The laser isn't just appearing and dissappearing, it's consitently visible enough to be identified as such. Not an easy feat with a pocket pointer, even if you could find a green one.

[Lonesome in Massachussets]

How does 'rare' come out as 'completely attributable to suggestibility'?

If actual incidents were fairly common, a certain percentage would likely be attributable to reports of things that aren't really there. When they are so relatively uncommon (with no evidence except the recollections of the aircrews) one cannot discount the possibility that all or nearly all the events are attributable to "the mind playing tricks."

[Hunble]

The laser isn't just appearing and dissappearing, it's consitently visible enough to be identified as such.

State your source of this information please!

Remember, just a quick flash of green light, only takes a split-second to recognize as being unusual.

I could randomly flash a laser at you, and you would immediatly recognize it as such.

[Djarum]

These lasers should be outlawed right away and the maroons highlighting the cockpits should be put on trial with lots of publicity.

Pure hysteria. These lasers are no more dangerous than a flashlight at 3000+ feet.

Outlaw lasers and only outlaws will have lasers.

[Hunble]

Pure hysteria. These lasers are no more dangerous than a flashlight at 3000+ feet.

How bright is a star at night? Can you see it?

What is unusual, is a green flash originating from the ground. Nothing dangerous, but unusual.

Many people have falsely stated that a very low power laser (such as a laser pointer) could not be seen from many miles away.

Once again, I will use the example of a faint star at night.

Think about it!

[radu]

The laser isn't just appearing and dissappearing, it's consitently visible enough to be identified as such.

State your source of this information please!

Here's one source. The last sentence in the second paragraph on this thread states just that.

What bothers me about this case is that the plane was taking off, not landing, when the beam hit.