Ben Longden Posted October 2, 2007 Share Posted October 2, 2007 By Fiona Connolly October 02, 2007 01:00am Article from: </IMG> A CHANNEL Nine helicopter crew filming the NRL grand final narrowly avoided disaster after a laser beam was shone from the ground, temporarily blinding a cameraman. The potentially fatal "idiotic" attack is the latest in a disturbing number of laser beam assaults on aircraft, with an ambulance helicopter transporting a critically-ill patient forced to delay landing after being attacked while flying near Sydney on Saturday. Cameraman Darren McDonald was stunned by a green glare when it hit the lens of his camera just before the players ran on to the field around 7pm (AEST) during Sunday night's game. "It shot into the camera lens and he was momentarily dazzled - if it had hit the pilot in the eyes and he's supposed to be controlling the aircraft, that's the danger," Nine's new director of news, Ian Cook said. The crew immediately notified air traffic controllers. Police said the far-reaching laser beam came from a park nearby the stadium. A police spokesman said the beam appeared to come from a building or house in Carnarvon St, Silverwater, however a search and door-knock of the area failed to find the source. "People think it's fun but they don't understand just how dangerous it is and unless something isn't done to stop it, sooner or later there will be tragedy," pilot Brian Gettens said yesterday. The weekend attack on the emergency medical helicopter en route from Nepean Hospital to Royal Prince Alfred Hospital was the second time pilot Darryl Humphries has been hit in the past three weeks. "This is happening more and more now and apparently it's a fun thing to do - it's idiotic, crazy," Mr Cook said. Qantas aircraft have also been targets, with one hit by a green light as it approached Brisbane airport earlier this month and another hit while landing at Darwin airport in August. More than 170 reports of laser attacks on aircraft have been reported to the Civil Aviation Safety Authority in the past year, with 49 reported between April and June this year. Link to comment Share on other sites More sharing options...
Guest Fred Bear Posted October 3, 2007 Share Posted October 3, 2007 Love the sensational headlines. Bloody media It was actually the cameraman who was affected and not the pilot (well not this time anyway) but I think saying it narrowly avoided disaster is a little far-fetched. Link to comment Share on other sites More sharing options...
Guest Andys@coffs Posted October 3, 2007 Share Posted October 3, 2007 Love the sensational headlines. Bloody media It was actually the cameraman who was affected and not the pilot (well not this time anyway) but I think saying it narrowly avoided disaster is a little far-fetched. I have a view that the recent spat of events has been largely exacerbated by the media sensationalism. While I'm all for the idiots who do this to be chased by the law (with about as much chance of capture as I have winning lotto, and I don't even play) I dont see what value, if anything th media brings. After all, despite the sensationalism, with the distances involved, and the impact of the inverse power laws of physics the impact of the lasers is small, there is no immediate death spiral or explosion In not even convinced that there is any short or long term eye damage potential. If nothing was publicised the perpetrators would go back to burning ants with a magnifying lens. So to use that crude acronym the media should STFU. Andy Link to comment Share on other sites More sharing options...
Guest pelorus32 Posted October 3, 2007 Share Posted October 3, 2007 It appears that the inverse square law does not apply to laser beams - the beam of known power covers the same area at any distance from the source (almost) compared to a normal light beam that spreads in all directions. I think that there is potentially a real issue with distraction and glare. Some lasers at least are permanently damaging to the eye. Still the media does beat it up. Regards Mike Link to comment Share on other sites More sharing options...
Ben Longden Posted October 3, 2007 Author Share Posted October 3, 2007 In the NINE news helo, the camera operator sits BEHIND the pilot. Thats about one metre. How do I know? because I work in the media, and sell news vision to NINE news as well as WIN Television. If you object to the news, then switch off the TV, shut the 'net at home, don't buy any papers, switch off the radio and dont gossip over the fence or at work. I have been dazzled by a laser pointer, when driving a car, about seven years ago I might point out, and I was seeing stars for hours. The immediate effect was a squiggly red line over my eyes, and it was bloody hard to see where I was going for about 30 seconds. When studying physics, we did lasers, and I did a special piece on them. The key to the laser is the fact the light is coherent, in other words, photons travel in a parallel path to each other, which explains why laser light does not spread out over distance - the inverse square law. This fact is used to advantage by laser distance measuring devices, including those used to measure the distance from earth to the moon. Ben (Obviously a bastard who works in the bloody media) Link to comment Share on other sites More sharing options...
Guest Fred Bear Posted October 3, 2007 Share Posted October 3, 2007 Ben, point taken. It is no joke and a serious matter and these idiots who do this, I personally think, need more than two years in the slammer but saying it narrowly avoided disaster is an absolute ridiculous headline. It's far-fetched and inaccurate. Now if that was the headline and you read down and it was revealed that the nine chopper had an engine failure over the Telstra Stadium then that would be a fair headline. When I did work experience at News LTD I was told by several senior journalists that sensational headlines were designed to sell the paper. That, and now I know that PBL (nine) has shares/part ownership in MSN where most of this news originated. I will stick to my guns and say yes, a serious dangerous act by the moron that did it, but a bloody ridiculous headline by the media. Link to comment Share on other sites More sharing options...
Guest bateo Posted October 4, 2007 Share Posted October 4, 2007 That must of been why Cameron Smith was missing his goal kicks from straight in front, having a laser pointed to his eyes!!haha I agee Chris... It got our attention, I am sure though the 'idiot's' would have been trying to aim for the pilot!! Link to comment Share on other sites More sharing options...
Guest Andys@coffs Posted October 4, 2007 Share Posted October 4, 2007 ... If you object to the news, then switch off the TV, shut the 'net at home, don't buy any papers, switch off the radio and don't gossip over the fence or at work. ... Ben (Obviously a bastard who works in the bloody media) Ben I don't object to the media in totality, I just think that when reporting events some consideration as to the total impact of the report should be made. I understand thats a decision that probably cant be prescriptively written down, however my view is that much of the recent occurrences are copycat occurrences that wouldn't occur, or would taper off over time if they weren't reported in the broader media. Given the impact on aviators then it should be reported in aviation specific media, but not on the 6pm news for every occurrence with a potential "me to" copycat the next day. Now with all that said, thats a personal view and as such others may not agree with me, which is all good in a democracy. I stand corrected regards the inverse square law, however note that something (dust, air, moisture, impurities in the fibre etc) must attenuate lasers over distance, otherwise fibre optic repeater stations would be clearly not be required, yet they are. I also note that the coherency discussed, is not perfect as distance increases in reality if it were so then the likelyhood of the fool on the ground actually getting that 2mm wide max beam to intersect a pilots eyes would be near on impossible. If the 2mm beam ia actually 10 cm in diameter in the cockpit then the energy density per square mm is significantly different. Anyone agree/disagree with this logic/fairytale? Perhaps, like you, I might think differently if it had occurred to me. Don't consider for one moment that I don't think its a cowardly d#ckhead thing for someone to do, it is, and if caught the full force of the law should be brought to bear, the question then, is should that be sensationally publicised, I think not. Andy Link to comment Share on other sites More sharing options...
hihosland Posted October 4, 2007 Share Posted October 4, 2007 Ben did say "When studying physics, we did lasers, and I did a special piece on them. The key to the laser is the fact the light is coherent, in other words, photons travel in a parallel path to each other, which explains why laser light does not spread out over distance - the inverse square law. This fact is used to advantage by laser distance measuring devices, including those used to measure the distance from earth to the moon." So what is measured in the distance measuring devices? Time for the signal to return? It would have to be some incredibly short interval for short distances. Or is something else measured such as a phase differential? Or the dispersal pattern? or the intensity differential? Just thinking Davidh with to much time for thinking Link to comment Share on other sites More sharing options...
Guest Andys@coffs Posted October 4, 2007 Share Posted October 4, 2007 In fact I went looking to see what divergence is typical in the hand held laser pointers and concluded that the average is about 1.2 - 1.5 milli Radians. My maths isnt perhaps as good as it once was so I think to get a view as to what divergence would occur over a 1000ft range (simplified to assume a 90degree right angle triangle I simply do 1000 x sin( .00012) (with the calculator set to radians instead of the dfault degrees). If my math is correct that identifies that the spread at 1000ft is then 1.19ft. If that is correct and we started with a 1.5mm beam then we end up with a 365mm beam, or 4.7 square mm (pi x 1.5) vs 1147square mm being an increase of 244 times. if 5mW of power was originally present in the 4.7mm^2 the the density per mm^2 is close to 1mW per mm^2. At 1000ft its 4.3 microWatts per mm^2 Can anyone see anything wrong with the math? Andy Link to comment Share on other sites More sharing options...
Kaz Posted October 4, 2007 Share Posted October 4, 2007 The lasers are not necessarily small hand held type, but large torch like laser used for astronomy. Some of the laser hits are accidental due to astronomers star gazing but many (probably most) are deliberate. The following is an article from Callback, NASA's Aviation Safety Reporting System. Laser illumination of aircraft cockpits may cause a number of hazardous effects, including pilot distraction, glare, after-image flash blindness, and in extreme circumstances, persistent visual impairment and inability to perform flight duties. According to the Air Line Pilots Association (ALPA) Operations Bulletin 2007-04, lasers continue to be a threat to aviation. During the first five months of 2007, over 200 “lasing” incidents were reported despite law enforcement efforts to deter and apprehend those who intentionally illuminate cockpits with lasers. The rise in laser incidents in recent years is believed to be due to the proliferation and increasing sophistication of laser devices available to the general public. On January 11, 2005, the FAA issued Advisory Circular (AC) No. 70-2, Reporting of Laser Illumination of Aircraft, in response to numerous documented incidents of unauthorized illumination of aircraft by lasers. This AC provides guidance to air crews on the reporting of laser incidents, and recommends mitigation actions to be taken to ensure continued safe and orderly flight operations. A review of laser incidents submitted to ASRS during the past year-and-a-half provides compelling evidence of the effects of sudden laser illumination in the cockpit. For one First Officer (the Pilot Flying), a laser flash produced a lingering after-image. Turning base to final, Runway 9R, I saw a very brief, bright green flash about 5 miles NNE of our position, in my right eye. Although not painful, I could feel an unusual sensation in my eye. The light was distracting and caused an ‘after- image’ to remain in my visual field for about 20 minutes after exposure. I was Pilot Flying, and was able to continue and land normally. After landing, I telephoned my airline’s Operations Center to inform them of the event, and they forwarded my report to TRACON.... A Flight Instructor and student were temporarily blinded by a laser aimed at their aircraft. My student and I were in cruise and we both noticed a glare on our left passenger window. Both of us turned to look at what was causing it and saw a ground-based laser which was striking our aircraft. It was turned off and then on a total of 3 times before it stopped. The fact that it was turned on and off more than once and that it struck us each time caused us to believe it was intentional. We reported it to Approach...It was blinding but not debilitating. In an especially graphic laser event reported to ASRS, a Captain suffered blistering and temporary vision loss as the result of a laser incident at FL360. More from the First Officer’s report: As I turned my gaze from [the] right side cockpit window, I observed a reflected flash from the left side of the cockpit. The Captain was looking out of the left cockpit side window at the same moment and asked me if I saw ‘that flash.’ I informed him that I only saw the reflection...The Captain then asked rhetorically if that might have been one of those unauthorized lasers. This made it clear to me that he had observed something far more intense than I had perceived. Based upon the...sensations the Captain was feeling in his eyes and with his suggestion, I made an ‘unauthorized laser’ report [to] the Center...After several more minutes, the Captain complained of less than clear vision, but nothing ‘too serious.’ We landed...approximately 50 minutes later...Once on the gate with the opportunity to directly observe the Captain’s eyes in good conditions, it was obvious his eyes were extremely bloodshot with what appeared to have been blistering and possible bleeding at the inside corner of his right eye. He was then complaining of increased discomfort in both eyes and blurred vision in the right eye...I accompanied the Captain to the hospital near the airport so that a physician could examine his eyes...The Captain’s retina was not damaged, but his normal 20-15 vision was temporarily 20-60...The FBI has contacted the Captain and interviewed him about this event.... Advisory Circular 70-2 details the reporting procedures to be used by air crews who experience a laser illumination incident, and suggests practical actions pilots may consider taking before, during, and after encountering laser activity. Immediately report the laser incident to ATC, including the event position (e.g., latitude/longitude and/or fixed radial distance), altitude, direction and position of the laser source, beam color, and length of exposure (flash or intentional tracking). Pilots flying in uncontrolled airspace are requested to immediately broadcast a general laser illumination caution on the appropriate UNICOM frequency. This general caution should include the following elements: Phrase “Unauthorized Laser Illumination Event” Event time (UTC) and general positional information (e.g., location and altitude) General description of event (e.g., color, intensity, and direction of beam) [*]Pilots should avoid flight within areas of reported ongoing unauthorized laser activity to the extent possible. [*]If laser activity is encountered while pilots are in contact with ATC, pilots should obtain authorization prior to deviating from their last assigned clearance. [*]Pilots should avoid direct eye contact with lasers and should shield their eyes to the maximum extent possible during a laser incident. We hope this information on laser illumination hazards has been useful, and we would appreciate any additional reports to ASRS on laser incidents. Link to comment Share on other sites More sharing options...
Kaz Posted October 4, 2007 Share Posted October 4, 2007 I don't really understand any of the technical guff about the lasers, but check out the pics for an example of the range possible... http://www.laserglow.com/index.php?hercules Link to comment Share on other sites More sharing options...
Guest Fred Bear Posted October 4, 2007 Share Posted October 4, 2007 As Kaz says these are larger lasers ones that run from the mains not your AAA hand-held type. Easy to run them from a vehicle too by means of an inverter. These people really do need to be locked up or learn how to do something more constructive with the time they have on their hands. Link to comment Share on other sites More sharing options...
Guest Fred Bear Posted October 4, 2007 Share Posted October 4, 2007 Well then, maybe some are hand-held. Unreal range on those things! Link to comment Share on other sites More sharing options...
Guest Andys@coffs Posted October 4, 2007 Share Posted October 4, 2007 As Kaz says these are larger lasers ones that run from the mains not your AAA hand-held type. . I wouldnt be so quick to dismiss the handheld laser pointers, in looking tonight it became clear to me that the lower powered green units could be had for under $100Aud. The higher power ones that Kaz I think is refering to seemed to be much more expensive than $100Aud with some handheld units (greater than 250mW output) being in excess of $1000Aud. If my suspicions that these are bored teenagers is true I can see them coming up with a hundred dollars, but struggling with the 200-1000 dollar items. I also noted in the reviews that the 250mW laser burns paint.... if these are the items in question then not only does the media have some culpability... What reasonable reason does a teenager have for needing something as dangerous as this and what reasonable retailer would sell this without questions being asked? Andy Link to comment Share on other sites More sharing options...
Guest Fred Bear Posted October 4, 2007 Share Posted October 4, 2007 Perhaps recording details with the purchase for these items as you would for say firearms, fireworks etc and needing to have a legitimate use for these items. I guess you can never totally enforce this sort of stuff because of sites like Ebay etc. I am sure there are people that have a legit use for these things but using them in this way is crazy. Link to comment Share on other sites More sharing options...
Guest pelorus32 Posted October 4, 2007 Share Posted October 4, 2007 For divergence calcs see here: http://www.pseudonomen.com/lasers/calculators/ M Link to comment Share on other sites More sharing options...
Guest Andys@coffs Posted October 5, 2007 Share Posted October 5, 2007 Thanks Mike I tried the calc on the link you provided and it confirmed that my calcs (divergence portion) above were correct. If the power density calcs are correct, then even if the laser usered were the 250mW paint burners, at 1000ft the density would be approx 200microwatts per mm^2. Assuming pupil dilated to max (8mm diameter), then the mm^2 on the open pupil is around 23mm^2, or intotal about 5mW of power, which puts it back to the low power pointers. That being true, maximum annoyance value but probably no lasting damage. At FL 390 an RPT crew shouldnt even have any real short term effects. At 300ft on short final....I dont want to contemplate that! Andy Link to comment Share on other sites More sharing options...
eastmeg2 Posted October 5, 2007 Share Posted October 5, 2007 Hi Andy, At small angles of less than a few degrees, or less than a 10th of a radian the calculations are pretty linear and complex trigonometry expressions can be dispensed with. In your earlier post you mentioned a distance of 1000ft. This is your radius, hence it is also your 1 radian arc distance. 1.2 milliradians = (1.2/1000) x 1000ft = 1.2ft. Cheers, Glen Link to comment Share on other sites More sharing options...
Ben Longden Posted October 5, 2007 Author Share Posted October 5, 2007 When I got 'lased', it was with one of those $50 ones from tandy about seven years ago. The distance was less than 30 metres, and I can tell you it was not a nice experience. We had a spate of cars being lased, and the local paper did a story on it - and an even nicer one when the plods caught the b'stards. The only thing was as the paper does not do court reports, we never found out what happened to them.... lethal injection, hanging or firing squad...? Ben Link to comment Share on other sites More sharing options...
BigPete Posted October 5, 2007 Share Posted October 5, 2007 Unfortunatley it was probably a smack on the wrist..... regards Link to comment Share on other sites More sharing options...
Ross Posted October 5, 2007 Share Posted October 5, 2007 There are plenty of lasers used by earth moving contractors using "laser buckets with laser detectors & controllers fitted" of various descriptions to produce uniform slopes on surface irrigated land after the land has been grid surveyed and the figures processed by a "Land-forming" program on a computer. The rotating lasers used are set up in the paddock on a fixed platform or tripod rotating around 300 to 600 rpm and are detectable by the scraper mounted receivers up to about 600 metres radius. The height error due to the curvature of the earth is increasing rapidly once you get past those numbers and stuffs up the slope of the surface being produced and the "balance" of the cut & fill volumes. If we get it right at the end of the job there is no dirt left over or holes to fill. It balances. Those lasers are set to concentrate the beam to about 10 mm diameter at around 300 m radius and gradually increases beyond that due to scattering in the air and the way the beam is focussed or collimated. These beams start off at about 4 to 5 metres above the ground but obviously can be seen as a flash at car or person height quite some distance from the transmitter if it was in your field of view. A sighting at ten kilometres would not be unusual but the light would be of very low intensity because of the spread and the rotational speed. Regards Link to comment Share on other sites More sharing options...
Guest Andys@coffs Posted November 12, 2007 Share Posted November 12, 2007 So, I have to eat humble pie again. Heres an example where the idiot chose the wrong target, being the SA Polair, An arrest followed shortly, of greater interest was the 2nd offence. http://abc.net.au/news/stories/2007/11/12/2088207.htm?section=justin Andy Link to comment Share on other sites More sharing options...
Flyer Posted November 12, 2007 Share Posted November 12, 2007 http://abc.net.au/news/stories/2007/11/12/2088207.htm?section=justin And I hope they kick the living out of the . Obviously he's a bright lad judging by his actions. No sympathy for the :censored:head. Link to comment Share on other sites More sharing options...
Guest J430 Posted November 12, 2007 Share Posted November 12, 2007 Pretty much sums it up! Link to comment Share on other sites More sharing options...
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