# Looking for news article on laser as survival rescue signaling device for long range.



## mzil (Jul 24, 2012)

I read that there is at least one news story of a stranded individual signaling distant rescue search parties (boats on the horizon?) by using his consumer laser pointer, he happened to have on him, and it worked! 

I'm thinking of including one in my survival kit for this very purpose, super long range emergency signal flashing, but I can't find the article. Anyone have any leads for me? Thanks.

Also how spread out is the beam, on average, after, say a mile?


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## Steve K (Aug 8, 2012)

interesting concept, especially for nighttime circumstances. To evaluate the concept, you might try finding a spot on a quiet country road and bouncing a laser pointer off of a reflective road sign. I would think that your ability to accurately point the laser would be a bigger limitation than the width of the beam.

For daytime use, my guess is that the standard signal mirror would be more effective. Most have an aiming tool built into them, and the amount of light reflected by the mirrors would seem to exceed the amount of light produced by a laser pointer by several orders of magnitude. I have a small military signal mirror used by pilots, and I've been impressed by how easy it is to aim. The fact that it won't run out of power is a nice feature too.

Steve K.


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## AnAppleSnail (Aug 8, 2012)

mzil said:


> I read that there is at least one news story of a stranded individual signaling distant rescue search parties (boats on the horizon?) by using his consumer laser pointer, he happened to have on him, and it worked!
> 
> I'm thinking of including one in my survival kit for this very purpose, super long range emergency signal flashing, but I can't find the article. Anyone have any leads for me? Thanks.
> 
> Also how spread out is the beam, on average, after, say a mile?



CPF Laser Signal search


It's chancy. To use one of these lasers, you want a high-divergence beam, and the visibility is limited at night. Also, YOU have to point the laser "close enough" to the rescuer (Within the divergence of the beam), AND he has to look directly towards you and see a winking green dot...and then recognize this as a distress signal. 3 red flares is a universal, absolute distress signal, visible for dozens of miles. A green laser might be dismissed as someone playing with lasers.

Lasers: Line of sight, only. It is my experience that the beams are rarely visible when it's not pointed at you, so you can't make a shining beam of light into the sky. Not a universal distress signal yet. Requires conscious, precise aim. Cheap lasers are not survival-reliable.


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## mzil (Aug 8, 2012)

Steve K said:


> interesting concept, especially for nighttime circumstances...For daytime use, my guess is that the standard signal mirror would be more effective.


Yes, my concept is to use a laser at night, and a mirror for sunlight.



> the amount of light reflected by the mirrors would seem to exceed the amount of light produced by a laser pointer by several orders of magnitude.


 Quite the opposite at night.


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## mzil (Aug 8, 2012)

If people think I can't possibly construct a device that would have any actual usefulness, such as attaching a line generator to a very affordable laser pointer, and only commercial versions could possibly work, then fine, whatever, I don't care; we'll just have to agree to disagree. I also don't have the time or inclination to address all the various naysayers' objections, point by point, so I wont, but I'm _still_ looking for this *news article* I spoke of, peeps, just like my title indicates. Links to other forum posts or the existing _commercial_ vendors of survival laser signaling devices don't interest me; I've already _seen_ those.

I also no longer need help in calculating how spread out the beam is per distance, aka beam divergence; I've since found (on my own) an  on line calculator  for that.


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## bshanahan14rulz (Aug 9, 2012)

All I find is news stories about people who grounded a US Coast Guard search party looking for crew of a wrecked ship by shining green lasers at them.


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## AnAppleSnail (Aug 9, 2012)

I'm able to find laser companies giving an anecdote of 'a film where a couple on a mountain signal a plane.'

I'm able to find laser sellers saying "It will light your fire and signal for rescue and stun wolves and muggers." click

I'm able to find research groups talking about "Gee it'd be nice to replace flares with lasers." click

Here is a review of a laser flare: click "Please note that the maximum rangees that follow were predicated on knowing where to look as the lights were very dim at this maximum. This may be applicable in a search where they are looking for you in a particular area. If you are trying to attract attention from a passing aircraft, useful range would be about one half the maximum in most circumstances." They found a 20 mile range at night, when the aircraft knew where to look. They found the green laser to be ineffective in bright daylight, with 80-90% reduced range on heavily overcast days. Their conclusion (2006) is that they're useful in some cases, and worth having, but not a flare replacement.

I was not able to find an actual instance of a laser signal being used for rescue. This doesn't mean it hasn't happened, but I'd expect to find:

1. User testimonial.
2. Sales literature with released names and dates
3. USCG literature saying 'We didn't approve these but they work.'


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## mzil (Aug 9, 2012)

bshanahan14rulz said:


> All I find is news stories about people who grounded a US Coast Guard search party looking for crew of a wrecked ship by shining green lasers at them.



I'm thinking you mean this news story, right?
http://www.heraldonline.com/2012/08/09/4176771/green-laser-blinds-coast-guard.html


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## AnAppleSnail (Aug 9, 2012)

mzil said:


> I'm thinking you mean this news story, right?
> http://www.heraldonline.com/2012/08/09/4176771/green-laser-blinds-coast-guard.html



That's the only place I can find lasers in context of an actual rescue. I can see how lasers have real advantages over flares - especially ones with better-for-signaling patterns. But I haven't been able to find any instances of them being used for rescue signaling either. Can you phone up a big-park park ranger, or a USCG, and ask their opinion?


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## moozooh (Aug 9, 2012)

Visibility isn't _that_ much of an issue for powerful lasers (think 200 mW and upwards) as their beam can be seen even before absolute dark, and the good part is that you can shine it above obstacles—something handheld flares can't do. The problem, however, is that flares are universally recognized signaling devices, and lasers aren't. Then again there's the Alpine distress signal that can be done using anything, including lasers.


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## mzil (Aug 9, 2012)

Flashing with an SOS pattern is unquestionably not "a person goofing around with lasers." and wouldn't be dismissed, even by angry police/helicopters who might initially think they were being maliciously "attacked" by some kid or terrorist. They would hunt you down if only to prosecute you! PLEASE DO, MY LIFE DEPENDS ON IT! I'd think more than 50% of the lay public would know what SOS means and more like 99% of search and rescue people would know.

As best as I can tell, worst case scenario is they save my life (that's really good in my book) and then send me to jail for 5 years or a $10,000 fine for the federal crime of shining a laser illegally. Unlikely, if you ask me, considering there'd probably be good evidence I truly was in a life or death situation, but still worth it, totally, considering _I'd be alive._ 

As for "your consumer laser pointer when aimed at the rescuers 1000's of feet /miles away, would blind them permanently, even though you were just flashing a sequence pattern": _I don't buy it_.


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## mzil (Aug 9, 2012)

If my recollection is true, that the one example on file of a person successfully flashing a laser distress signal (and was subsequently rescued) was indeed just from a run of the mill laser pointer he/she happened to have on them, I can see why the manufacturers of the professional versions wouldn't like their customers knowing that, because it could impact sales if anyone like me gets it in their head that a consumer could devise a much more cost effective version than what they sell. 

The trick is concocting a line generator for the tip so aiming is a casual affair and doesn't need binoculars and a tripod for stability and accuracy.

P.S. Anyone with the notion I am suggesting a very powerful laser shooting straight up so I'd be like a visible pin on a map (having a visible side beam) you are incorrect. Those lasers are way more dangerous and big bucks.


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## AnAppleSnail (Aug 9, 2012)

I agree that you won't shoot down rescue planes! Some pilots worry that they'll be dazzled out of scotopic vision by the laser, though. That could endanger them, if it happens. This probably required unrealistically close ranged of just a few km, and ridiculous laser output and collection. NOT the ideal laser flare.

I'd like to find that successful laser signaling to read and share. It seems a laser would be quite useful... But common fan filters are awfully wide.


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## bshanahan14rulz (Aug 10, 2012)

Some cheap lasers omit the expanding optics needed for low divergence. Other times, you can modify the outermost optic's focus distance and sometimes change the divergence of the laser to match your needs. Think DEFT, but with more throw, and only a single wavelength.


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## mzil (Aug 12, 2012)

I found a lead for the news story, but unfortunatly the link they reference isn't working:

"Laser pointers can be used in hiking or outdoor activities. Higher-powered laser pointers are bright enough to scare away large wild animals which makes them useful for hiking and camping.[_citation needed_]​ In these circumstances a laser pointer can also serve as a handy survival tool, as it can be used as a rescue signal in emergencies which is visible to aircraft and other parties, during both day and night conditions, at extreme distances.* For example, during the night in August 2010 two men and a boy were rescued from marshland after their red laser pen was spotted by rescue teams*.[14]​

http://en.wikipedia.org/wiki/Laser_pointer

I'm wondering if maybe they've pulled the story because they don't want to promote the concept of aiming lasers at aircraft under ANY circumstances? Just random speculation, I have no backing evidence.

UPDATE: FOUND IT!

http://www.dft.gov.uk/mca/mcga07-ho...s-releases.htm?id=BFA1055881F4854A&m=8&y=2010

I wonder if they then arrested the 13 year old boy? [joke]


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## marcham (Aug 12, 2012)

At night any strobing flashlight will be detected from afar on NVG. The next best option is a PLB.

Do not under any circumstances point a laser at an aircraft or other potential rescuers as you are putting your rescue in jeopardy.

Sent from my GT-I9100M using Tapatalk 2


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## mzil (Aug 12, 2012)

> Do not under any circumstances point a laser at an aircraft or other potential rescuers as you are putting your rescue in jeopardy.



And you feel the same way about the commercial versions on the market, "they should be banned", or are they exempt from this rule ?
---

I have learned how to make line generators and am now experimenting with different fan angles.


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## Burgess (Aug 12, 2012)

mzil said:


> I'd think more than 50% of the lay public would know what SOS means . . . .




Sad to say . . . .


I don't think 50% of the lay public would even know 

how to tell time from an analog Clock !

(non - digital)



_


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## mzil (Aug 13, 2012)

^ Says one youngster to the other [both caucasian, not that it matters]:

"Yo, Dart Gun."
"Yeah, Hipsta?"
"Check it. There's a monochromatic light flash on the distant horizon. I think it's some sort of binary sequence ."
"Word. I think maybe 'one, one, one, zero, zero, zero, one, one, one'' and it keeps repeating. Probably just some idiot left their turn signal on."


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## marcham (Aug 14, 2012)

mzil said:


> And you feel the same way about the commercial versions on the market, "they should be banned", or are they exempt from this rule ?
> ---
> 
> I have learned how to make line generators and am now experimenting with different fan angles.



The commercial versions have been proven ineffective by the few rescue organization I know that have tested them. Under any sort of canopy, a flashlight is a much better option. Over open areas a flare is unmistakable and does not require any aim. A plb will always get you the help you need and it costs nothing to maintain.

Sent from my GT-I9100M using Tapatalk 2


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## mzil (Aug 20, 2012)

marcham said:


> The commercial versions have been proven ineffective by the few rescue organization I know that have tested them.



Please provide link(s) documenting this testing you speak of "proving them ineffective". Thank you.


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## mzil (Aug 20, 2012)

Here's a positive review from a Swedish S.A.R. helicopter group noting the commercial Greatland Laser Flare is effective and safe in their actual test of it:

http://www.greatlandlaser.com/Baltic_Sea_Test_March8_2010.pdf

"...no problem to see at all. Everyone was quite impressed and a bit surprised."

"...no harmfulness...[due to blinding]"


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