# Green Laser for Rescue/Signalling



## kosPap (Aug 3, 2010)

I am considering adding a green laser in my kit just for the shake of signalling....(I guess some of you have already seen this: http://www.equipped.org/rescuelaser.htm)

I am total newbe on this and do not know anything about power needed (need a beam that will reach several kilometers). Any chance I will getby with 5mW ones

How about modes? Are there any vailable options?

How about a lser or a pointer? My main concern is durability

And buying one must be easy and relatively cheap...
That means that i am looking at the Romisen L-030 30mW one for now....

Thanx, kostas

and what power consumption (amp draw)? what do the 30mW ones draw?


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## alpg88 (Aug 3, 2010)

good idea, i thought there could be practical use for lasers in my moded lanterns, 
last time i was camping, there was a mountain 2-3 miles away, my green 50mw had no problem reaching it.


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## Raccoon (Aug 4, 2010)

You have to really consider whether you are worth rescuing in the first place.

Seriously, how often do you find yourself a thousand miles away from civilization?


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## kosPap (Aug 5, 2010)

on rescue, you never know....in our mountains there are cravaces...easiest thing to get out is a laser

I am in Emcoom/HAM....hence the need for signaling.....easiest way to mark a site for search parties in the forest, or the psoiion of a field antenna in the middle of nowhere


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## barkingmad (Aug 5, 2010)

It's not just the power of the laser that is important - it is the shape of the beam. The rescue lasers project a 'line' of light whereas normal lasers are just a pin point - a line is far easier to aim / covers a much larger area.


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## kosPap (Aug 5, 2010)

just a sec....

does the same holds true for the Green lasers?

I am lokking towards them for this line alone...and maybe a forward switch


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## barkingmad (Aug 5, 2010)

Green or red should both be ok - for the same power (i.e. 5mw) green tends to appear brighter than red as I believe your eye is more sensitive to that part of the spectrum.

Also from a SAR perspective I suppose green looks more unusual - but there again a blinking red light should also get their attention if actively looking for you / someone.

Personally these rescue lasers are a good idea but you have to think they would probably need to be looking for you already - a PLB (personal locator beacon) is a much better idea?


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## bshanahan14rulz (Aug 5, 2010)

get a focusable green laser. I think aixiz sells "line generators" that screw into aixiz modules, which seems to be a standard threading for pen-style focusable lasers.

I have a "30mW" that is still quite bright, beam visible at night, etc. etc. 

I also have a 160mW that can hit low clouds. That one I am having a heatsink made for it and putting it in my solarforce L2 :twothumbs


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## kosPap (Aug 5, 2010)

do you mean that a straight green line is not attainable with the run-of-the-milll lasers & pointers?

So I need a module that has this?

Well I will admit that I have concerns of importing it in my country (I am not located in the US)..Dx stuff seems it fliew under the radar.
Realistically what should I expect by the Romisen L-030 30mW one
(sorry if that seems too persistant with teh DX stuff but it is easy)


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## alpg88 (Aug 5, 2010)

only in bright daylight i can't see the line, also in very clear weather line is not so bright and clear, but in most conditions, at night you will clearly see the line of my 50mw for miles, you will get noticed. and if there is a but fog, mist or moisture in the air, you will definitely not miss it.
i got it from dx, btw it is only assembled laser pointers above 5mw are banned from importation (at least in us), but modules as parts are not restricted


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## Raccoon (Aug 5, 2010)

Honestly and truly, you don't need a line to sweep for attention of a distant party. Spreading the beam out will only significantly weaken the output at the distant target. Besides, after only 1 mile distance, the dot from a regular laser pointer (at 1.2 mRad) is greater than 6 feet in diameter (the size of a person). If you can't hit someone with that, you're probably not aiming.


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## bshanahan14rulz (Aug 6, 2010)

I think that the honda S2000 looks amazing coming down the street towards you at night. Even if it's very far away, you can tell what it is because the light pattern of the headlights has such a sharp cutoff and it bounces up and down, causing it to appear to be flickering with beautiful blues and violets. 

I think it is this flicker effect that will be very attention-grabbing. While a line generator will help make this easier to achieve if you do not know who you are aiming at, alpg and raccoon are right that if you know what you're pointing at, it is easy to get their attention with a normal beam.

You may not be able to see the beam of a 30mW in the daytime, which would hinder aiming accurately, but at night time it will be easy to make the line point at your target/rescuers.


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## kosPap (Aug 6, 2010)

bshanahan14rulz
seems you are into this.....Looking at the usage instructions at the rescue light website i was about to ask about how fanning of the line is achieved. 
http://www.greatlandlaser.com/images/demonstration/fan-of-light.gif
Now I know the limitations of a run-of-the-mill pointer...

No daytime performance and no fanning...

Many thanks...

PS Can anyone explain how this "fanning" is achieved?


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## bshanahan14rulz (Aug 6, 2010)

In the way they describe it, imagine holding a flashlight pointed to a wall, except instead of a beam pattern, it displays a vertical line. If you wag the flashlight back and forth, you sweep this vertical line from side to side. This guarantees that some photons will hit your target if it is within that sweep. 

This is the same procedure you would use if you just had a pointer and needed to attract the attention of a helicopter pilot or something. It's a given that you aren't going to be able to hold the laser steadily on the helicopter, but if you wave the laser from side to side, it is more likely to hit an object along that line.

Once you have a laser in your hands, it will make much more sense.


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## kosPap (Aug 7, 2010)

aha! thanks... I thought it was a special feature of a beam creating a slice of pizza like light sector.....


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## Philip2 (Dec 9, 2013)

bshanahan14rulz said:


> In the way they describe it, imagine holding a flashlight pointed to a wall, except instead of a beam pattern, it displays a vertical line. If you wag the flashlight back and forth, you sweep this vertical line from side to side. This guarantees that some photons will hit your target if it is within that sweep.
> 
> This is the same procedure you would use if you just had a pointer and needed to attract the attention of a helicopter pilot or something. It's a given that you aren't going to be able to hold the laser steadily on the helicopter, but if you wave the laser from side to side, it is more likely to hit an object along that line.


What then is the advantage of the Greatland Rescue Laser Flare over a cheap and simple laserpointer that is just manually waved in a survival emergency? 

Could the use of such a cheap and simple laserpointer be acceptable and effective, if it is just used as a vertical light saber in front of airplanes and boats, without aiming directly at them? This light saber effect will be more visible in the dark, if there is a little fog in the air, or low hanging clouds that can be shined upon. 

This waving with a cheap laser pointer could be rotated or alternated with sos with the same laser pointer.

I think the use of a laser pointer as a distress signal is only responsible in a critical emergency, because of the risks of accidently blinding or disorienting a pilot, car driver, etc.


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## AnAppleSnail (Dec 9, 2013)

Do they work? Sources vary. See this article: Previous CPF thread "Show me news articles on laser flares". The later links are relevant.

I would watch for durability and waterproofness. Also battery chemistry that functions in cold.


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## firelord777 (Dec 20, 2013)

AnAppleSnail said:


> Do they work? Sources vary. See this article: Previous CPF thread "Show me news articles on laser flares". The later links are relevant.
> 
> I would watch for durability and waterproofness. Also battery chemistry that functions in cold.



+1


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## bosummer (Dec 28, 2013)

Green laser pointer can emit the most sensitive color to naked eyes. It is able to be used for long distance targeting, rescue and signal because of its high visibility.


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