Ban of Handheld Lasers within 10k of airports

[B208]

Coherent means that the wavelengths of the light are in phase. This is important for data transmission applications and lots of experiments. For our "blind the pilot" task, this is irrelevant (unless you are trying to beam updated SOPs through his retinas )\

Actually coherence is very relevant when it comes to stopping people seeing things. A coherent light source generates nothing but interference patterns with itself when it shines on objects, which makes it impossible to use it as a source of illumination for vision.

However, the coherence length of hand held lasers is short, in the tens of metres. Beyond that distance the laser is effectively no longer coherent.

What you have written makes no sense. Just for reference, I have a minor in physics and used to teach physics.

[B208]

Just a thought here guys; Nothing says we can't peruse both education and enforcement. We make an effort to help people understand just how dangerous lasering an aircraft is and then we use thumbs screws on the ones that go ahead and do it anyways. I. am. brilliant.

[Rockie]

Just a thought here guys; Nothing says we can't peruse both education and enforcement. We make an effort to help people understand just how dangerous lasering an aircraft is and then we use thumbs screws on the ones that go ahead and do it anyways. I. am. brilliant.

Precisely what I've been saying. Educate with muscle for the slow learners.

[photofly]

What you have written makes no sense. Just for reference, I have a minor in physics and used to teach physics.

Look up laser speckle. Coherent light from parts of a rough surface that at your eye subtend an angle smaller than your eye's resolution yet whose distance from the source differ by more than a small part of a wavelength cause destructive interference (dark) and constructive interference (bright) patterning, which is not related to the "brightness" of the part of the object you're looking at if viewed under non-coherent radiation.

Just for reference, you don't scare me. I have a degree in physics, and I did too. So what? Neither is a guarantee of correctness.

https://www.rp-photonics.com/speckle.html

[rookiepilot]

Just for reference, you don't scare me. I have a degree in physics, and I did too. So what? Neither is a guarantee of correctness.

That and a buck and change will get you a Tim's, too.

[B208]

Look up laser speckle. Coherent light from parts of a rough surface that at your eye subtend an angle smaller than your eye's resolution yet whose distance from the source differ by more than a small part of a wavelength cause destructive interference (dark) and constructive interference (bright) patterning, which is not related to the "brightness" of the part of the object you're looking at if viewed under non-coherent radiation.

Now, that makes sense.

Just for reference, you don't scare me.

I've been working on making myself more approachable and less intimidating. I'm glad to hear that it's working.

[digits_]

Coherent means that the wavelengths of the light are in phase. This is important for data transmission applications and lots of experiments. For our "blind the pilot" task, this is irrelevant (unless you are trying to beam updated SOPs through his retinas )\

Actually coherence is very relevant when it comes to stopping people seeing things. A coherent light source generates nothing but interference patterns with itself when it shines on objects, which makes it impossible to use it as a source of illumination for vision.

However, the coherence length of hand held lasers is short, in the tens of metres. Beyond that distance the laser is effectively no longer coherent.

Won't your eyes get damaged either way if the beam hits you?

[photofly]

Permanent eye damage is caused by (as far as I know) retinal heating, which is caused by a high power per unit area of the direct beam hitting your eye. Lasers are topical for this because a laser beam is highly collimated, it doesn’t spread out quickly, the laser power stays concentrated for a considerable distance. To cause damage the laser must damage your retinal cells in the time before you blink, the blink reflex protecting your eye from sudden bright light. Anything under 1mW is unable to do that even close to the source where the beam is most concentrated.

I do read however that even a severely hazardous Class IV 1.5W laser of typical beam parameters is considered eye-safe after about 1000 feet.

Your retina can’t be damaged by laser light reflected off objects close to you: once the beam hits a rough object it spreads out and the power delivered to the area of your cornea (which is focused onto the retina) is very small.

Similarly, you can’t look at the sun without burning your retina but you can look at objects illuminated by the sun.

Now, infrared lasers - they’re really nasty. You can’t see the beam, so no blink will shield your eyes.

This page is interesting:

http://www.laserpointersafety.com/safet ... index.html

[B208]

Permanent eye damage is caused by (as far as I know) retinal heating, which is caused by a high power per unit area of the direct beam hitting your eye.
.....

Your retina can’t be damaged by laser light reflected off objects close to you: once the beam hits a rough object it spreads out and the power delivered to the area of your cornea (which is focused onto the retina) is very small.

Don't forget wavelength. A sufficiently short wavelength, (near the U.V. end of the spectrum), will break the chemical bonds in the molecules of the rods and cones of the retina. This applies to both direct and reflected light.

[photofly]

Permanent eye damage is caused by (as far as I know) retinal heating, which is caused by a high power per unit area of the direct beam hitting your eye.
.....

Your retina can’t be damaged by laser light reflected off objects close to you: once the beam hits a rough object it spreads out and the power delivered to the area of your cornea (which is focused onto the retina) is very small.

Don't forget wavelength. A sufficiently short wavelength, (near the U.V. end of the spectrum), will break the chemical bonds in the molecules of the rods and cones of the retina. This applies to both direct and reflected light.

Ultraviolet light does cause retinal damage, which is why you should wear only good quality UV filtering sunglasses, but laser pointers being nearly monochromatic (which is the point of a laser after all) produce radiation that's visible light and not ultraviolet. So I don't think that is a danger in circumstances of lasers being shone at aircraft.

[B208]

Permanent eye damage is caused by (as far as I know) retinal heating, which is caused by a high power per unit area of the direct beam hitting your eye.
.....

Your retina can’t be damaged by laser light reflected off objects close to you: once the beam hits a rough object it spreads out and the power delivered to the area of your cornea (which is focused onto the retina) is very small.

Don't forget wavelength. A sufficiently short wavelength, (near the U.V. end of the spectrum), will break the chemical bonds in the molecules of the rods and cones of the retina. This applies to both direct and reflected light.

Ultraviolet light does cause retinal damage, which is why you should wear only good quality UV filtering sunglasses, but laser pointers being nearly monochromatic (which is the point of a laser after all) produce radiation that's visible light and not ultraviolet. So I don't think that is a danger in circumstances of lasers being shone at aircraft.

No arguments about laser pointers being a virtual non-issue for eye damage. I was speaking more about the home-brewed versions (i.e. the ones built from scavenged CD burners etc....).

[goldeneagle]

All of the laser pointers on the market today are low power and red.

Green laser pointers are very common. 5mw glp on ebay runs 10 bucks with free shipping. We use them all the time at astronomy events, great for pointing out constellations and such for folks that dont know their way around the sky.

[digits_]

Your retina can’t be damaged by laser light reflected off objects close to you: once the beam hits a rough object it spreads out and the power delivered to the area of your cornea (which is focused onto the retina) is very small.

Agreed, you'd just see the red/green dot on the object the laser is pointed at. I'm not too sure what you are getting at in a "blind the pilot" scenario though? I don't think the glass from the windshield reflects the laser in sufficient amount to have any effect on the possible damage/discomfort the pilot experiences.

[photofly]

I'm not too sure what you are getting at in a "blind the pilot" scenario though? I don't think the glass from the windshield reflects the laser in sufficient amount to have any effect on the possible damage/discomfort the pilot experiences.

I don't know either; it wasn't me that used that phrase.

[B208]

All of the laser pointers on the market today are low power and red.

Green laser pointers are very common. 5mw glp on ebay runs 10 bucks with free shipping. We use them all the time at astronomy events, great for pointing out constellations and such for folks that dont know their way around the sky.

I stand corrected.

[AirFrame]

Someone will correct me if i'm wrong, but I was under the impression that the "blinding" of the pilot was more due to the sudden intense light coming in, not because of any physiological damage occuring (ie. laser burning out rods/cones in the eye). Not much different than someone sitting next to you in the cockpit suddenly shining an LED flashlight in your face. I'm not completely convinced that a common red, green, blue laser that can be bought for $100 or less would have good enough optics to keep a beam collimated well enough to maintain its damage-causing potential up to flight altitudes.

[Outlaw58]

Jumping in without reading the whole thread here so apologies if my contribution is minimal.

I was hit by a green laser last evening and inadvertently stared straight into the beam. Take-off phase of flight initial climb below 1000, PF with autopilot on. Let me just say it was VERY incommoding although the discomfort only lasted for a few seconds. After that I had a dark blind spot that while it did not impair my vision enough to abort the flight, it did persist while steadily fading until early this morning. I was able to see a doctor and ophtalmologist tech this morning which confirmed there was no damage to the retina to my relief.

Lessons learned from that incident:

1) While I wasn't injured, I believe Lasers CAN physically harm a pilot's vision
2) There are people out there that maliciously purchase powerful lasers and intentionally target aircrafts (I was naively believing to this point that incidents were of the inadvertent or negligent kind)
3) the discomfort and disorientation it causes definitely can cause a serious accident
4) I am seriously pissed and would very much like to find a laser user so I can inflict a large amount of physical pain to that person. (Well, I would settle with screaming very loudly at that person)

58

[digits_]

2) There are people out there that maliciously purchase powerful lasers and intentionally target aircrafts (I was naively believing to this point that incidents were of the inadvertent or negligent kind)

Sorry to hear that happened to you, but why did this event make you believe they wanted to intentionally blind you?

[Outlaw58]

2) There are people out there that maliciously purchase powerful lasers and intentionally target aircrafts (I was naively believing to this point that incidents were of the inadvertent or negligent kind)

Sorry to hear that happened to you, but why did this event make you believe they wanted to intentionally blind you?

I and 1 other crew member saw the origin of the beam (reported btw). From the way the laser was used, our aircraft was clearly the target of the user. There was not a iota of a doubt amongst the crew.

58

[AirFrame]

I and 1 other crew member saw the origin of the beam (reported btw). From the way the laser was used, our aircraft was clearly the target of the user. There was not a iota of a doubt amongst the crew.

The question asked was "how do you know they were trying to blind you?" I think we can all agree that they were intentionally trying to target the airplane with the laser, especially if it stayed with the plane for more than a fraction of a second. What's not clear is whether any malicious intent was there... That the holder of the laser wanted to harm someone with it.

Do you think if your co-pilot had reached over unexpectedly and turned on one of those high-brightness LED flashlights right in your face, that the effect would have been any different? Apart from you being able to immediately reach over and pummel him in person, that is? I still think that the effect of the laser at altitude is more of a "flash blindness" due to the intensity, and not a risk of "burning the retina" like one would get by accidentally looking into a laser in a laboratory. Temporary blindness due to sensory overload, but not permanent due to physical damage.

The end result could be the same, temporary blindness leading to loss of control and a crash, so the point may be moot, but i'm hoping to better understand the long-term effect in the event one lives through it. Good to hear you'll recover!