Previous thread, with more technical info. : L@ser attcks

I could be completely wrong here so feel free to correct me, but are we not talking about something completely different to the lecturer's laser pointer?

Those narrow beam devices have been used to attack bus drivers etc at short range, but I would doubt they are powerful enough or can be directed accurately enough to be more than the briefest flicker in the eyline of a pilot in flight.

There is obviousle something else out there that is far more dangerous and has no obvious 'practical' application.

I remember driving home one evening, not quite dark, and suddenly one of the large reflective roadsigns ahead lit up a very unnatural and vivid green colour. Not just a dot, but the whole roadsign! A little further on the same thing happened again and I realised that someone in the car in front was firing off something through the windscreen. I suspect this is what we are worrying about here?

theothersimon, Tarq57 and others...
 

I think your comments are a little out of date. These muppets are using items like this:

300mW 300 MW ADJUST FOCUS GREEN LASER POINTER TORCH NO4 on eBay, also, Laser Pointers, Gadgets, Consumer Electronics (end time 01-Sep-08 15:05:28 BST)

Freely available from ebay, and as you can see - a little more powerful than you suggest.

These idiots need to be prosecuted and put in prison. There is no valid reason for a normal person owning one of these.

Video here: YouTube - Green laser - 300mW Hulk Ultra lighting cigarette & matches

Thats how powerful they are, they aren't normal laser pointers.

Not your average pointer..
 

http://upload.wikimedia.org/wikipedi..._distances.gif

These high-power ( > 1mW ) green laser devices are actually far too powerful to be used as 'pointers' in presentations or lectures, as they are so powerful! The reflected light energy is blinding to the presenter!! (similar to the effect on the road signs mentioned).

I'm not sure of their initial concieved use, be it military or otherwise but I do know they have found a use within the amateur astronomy circuit .where they were used as 'star pointers' (to align telescopes and to point out stars to others). They are falling out of favour however, due to the issues surrounding pilot blinding incidents.

The only real way to stop this IMHO, would be to reclassify any laser pointer with a power output > 5 mW as a form of potentially offensive weapon, perhaps introducing a licencing scheme such as exists for firearms to allow for legitimate uses.

For more info than you could possibly want on lasers, see Sam's Laser FAQ: Welcome Page

Banned in the UAE
 

Don't try taking any type of laser into the UAE as they are banned. they make no distinction between types (1,2,3,4). Pen lasers or other similar laser pointy devices in hold or hand baggage will be confiscated and your name (passport details) will be added to the bad boy list!

First recorded 'attack' by green laser in Abu Dhabi was reported by an Etihad crew in 2006 on approach to AUH. The crew did the right thing and reported the incident to ATC who turned out the local police, no one was apprehended. The incident was reported in the local press about a week later and within a couple of days of the newspaper story numerous sightings of green and red lasers were being reported around the Emirate. Seems the local boys had discovered a new plaything! Seems things have gone quiet these days thankfully.

Unaware that they were doing anything wrong the GCAA gave out 'pen lasers' to anyone who visited their stand at an aviation exhibition in the UAE earlier this year! Boy that was embarassing!

Did King Harold lose and eye to a green or red laser, maybe I'm getting my history confused?:)

It's ludicrous that these things are legal at all in most countries. What gets me is that even a 125mW laser may or may not light cigarettes but it will still pop a balloon with ease. They should be treated like guns, only a person with a valid licence after an evaluation should be allowed to buy such things.

A police spokesman said a 19-year-old man had been arrested and charged with two coun
 

Nice, two counts =5 years inside should send the right message.............:ooh::ooh:

Ban this ban that bla bla:sad:

The basic rule with diode lasers is this. The more powerful the beam, the quicker it expands in diameter. The beam is focused such that at a very small distance from the aperture, you might be able to light a cigarette...or melt a hole in a black plastic bag. Prior to, and beyond this small area...the beam will NOT light a cigarette nor melt black plastic.

We must not succumb to the image of the "Star Trek" type phaser beam....they all disperse with the square of the distance away. As the knowledgeable poster on Page one said....the best lasers shot at the moon are 5 times the moon's diameter when they arrive there. If you were to look at the Earth from the moon (directly into the beam) you would most certainly NOT notice it.....it is that diverged.

For aircraft.....the beam operate the same way. It is very much wider (and hence weaker) than the millimeter beam width at the aperature. Combine this with topside cockpit windows, layed down at 45 degrees or more to the vertical, makes the beam pale in comparison to the landing lights on your wingtips.

IMO, people should not aim their lasers at planes and helicopters....in the rare instance where the impinging beam might refract in such a way as to briefly distract the pilot flying. And as such I do not think the "hang 'em high" attitude needs to be taken in light of the well known facts and physics of collimated(sp) monochrome light.

Actually not always true, at least at the low end of the power ratings in my opinion. Many of the more powerful DPSS lasers have much better divergence (e.g. less than 1.5 mrad) than a 5mw pointer. Some of the cheaper brands like New Wish use plastic optics so they do spread more regardless of power.

For all you rocket scientists, here's a technical discussion of laser beam divergence:

Melles Griot Optics Guide - Beam Waist and Divergence

I have to raise the B.S. flag on this gem of knowledge as well. Five times the moon's diameter would imply a beam divergence of 2.5 degrees, the astronomical lasers (and even laser pointers) do a lot better than that. From a recent article about the Lunar Laser Ranging Experiment:

From: Anthonares Blog Archive Bouncing Laser Beams Off of the Moon

Not that it matters - but the best lasers could make a spot on the moon about 2 km in diameter.

see this blog

This is the internet! Beware "knowlegeable" [sic] posters! :suspect:

Some might think this a bit extreme in these tree hugging,bunny s*agging days,but I would subject these scroates to a dose of their own laser device and then ask them to walk a 4" wooden beam.............which just happened to be suspended between two extremely high buildings:ok: Post the results on Youtube and then see if it happens again.Maybe I should start a website....Letsstopscumbags.com. :D

L@sers
 

Just phoned the Home Office re this problem. L@zers? Pilots? Eye damage? Safety of aircraft? They appear to know nothing about the problem.
However did give me an e-mail address where the issue could be raised with the Government. [email protected] Please write, just sent mine.

Having had one of these lasers targetted at my aircraft this week I can say that they are powerful enough to cause discomfort and distraction at 2,000' with the briefest of exposure. Ban them and prosecute - there is no debate.

Well I own a <1mW green pointer and it is attached too and harmonized with my Celestron C8 SCT, for use in the Astronomical field. I do hope that you are not getting me mixed up those bloody dangerous idiots who both supply and use the above!!:sad:

I Was Wrong, Three Years, Not Two Years.
 

Gentlemen, you may wish to draw this precedent to your legal colleagues.

From the Australian Broadcasting Commision (ABC)

It's time they banned aircraft from flying over areas where construction is taking place. A building has to stay up in the air for a hundred years, and these pontificating pilots want us to believe their needs are greater.

Interesting aside!
 

First time I've read this thread about laser pointers affecting air crew. In my past, I have studied astronomy and there is, rightly or wrongly, a growing trend amongst both amateur and professional astronomers to use laser pointers as an aid to point telescopes at targets in the sky and also to measure stability in the atmosphere.

Just thought it worth pointing out that they may not all be mindless thugs trying to bring us down but instead, unaware of the danger they are causing.

For what its worth, I'm doing my best to bring this danger to the attention of the astronomy community.

Mark.

Hmmmm.... My father used to be a hobbyist holographer twenty-plus years ago. He started out with a 5mW HeNe laser, at the time a tube slightly thicker than a kitchen paper tube roll, about three times as long. He then had a 25 mW HeNe laser which, as the 5 mW one, was in no way portable as connected to a mains PSU. This thing sat on his sand table encased in a rectangular aluminium housing, about 1.5 metres long.

I digress- How is it possible to shine a laser into an aircraft cockpit from below :confused:

How is it possible to accurately aim at the eyes of a pilot, given the width of a laser beam, the movement of the aircraft and, again, the fact that your laser wielder is surely on the ground, whereas the aircraft is in the air :confused::confused::confused:

Finally, a lot of cockpit glass I have seen is decidedly tinted (often veering towards the green?)- Whilst I appreciate there are many different wavelengths of coherent and non-coherent light, does this anti glare tinting (and anti-cosmic ray???) have no dissipating effect?

Maxbert