lasers for signalling

[ZEBRA]

lasers for signalling

This review is my own opinions and findings .
There is quite a debate going on at the moment as to the use of lasers to replace pyrotechnic flares there are pros and cons for both items the advantage a laser has are.
Longer shelf life (no expiry date)
Maintenance free
Smaller and easier to carry
Can be seen from greater distances
No explosion danger
No fire risk

The advantages pyrotechnic flares have are.
Universally recognised as a distress beacon.

Both have also disadvantages
With the laser .
Not yet recognised as distress signal .

Pyrotechnic flare.
Short shelf life (2/3 years)
Fire risk
Quite bulky so difficult to store.
Only last a few seconds

In my investigation in to lasers I have tried to show that they have every potential to be recognised as a distress beacon without the dangers and cheaper to buy and maintain in the long run

Firstly can I thank Paul from megagreen www.megagreen.co.uk/shopexd.asp?id=557&bc=no who has helped me along the way with both advice and supplying the lasers I have tested out all on loan to me for this review

Firstly the test equipment we have for this review 5 of the best lasers available for our tests they are all waterproof versions with re-chargable batterys we used a small wooden rack to make comparisons between different laser strengths and some special safety goggles as I would be using these lasers for quite a while during the tests and photographing


As you can see in the rack are 5 lasers from left to right they are powers.
10mW. 50mW. 100mW. 150Mw. 200mW




The particular lasers we used are high power and come encased in a rugged waterproof housing which I found very easy to use
it is very important to note that all lasers sold in the uk must by law have the power rating on the white sticker you can see in the photograph



the orange button you can see at the back of each laser is the on off button these differs from the cheap laser pointers in that they have a positive on off switch so they can be switched on while being used this is a real advantage because you don’t have to keep a small button depressed to make the lasers work you just switch it on and it stays on till you switch it off again



The first test is simply to show you all 5 lasers switched on and pointing at the sky
Note the different thickness of the beams and the difference between the red and green the green is clearly the way to go



This close shot shows the difference with the beams catching my breath they show up much brighter



A shot directly up in to the sky this would clearly be seen by any rescuers
Looking for you the beams seam to go on for ever note the lower wider flares on the beams this was picking up a light mist which was present during the photograph



During the photographs no editing took place to any of the photos and no colour enhancements were done to any of them either.
you can clearly see that lasers are the way to go for us in the future I think the only disadvantage would be getting the public to recognise them as a distress signal but they are certainly very visible and would make you more visible in a search and rescue situation during my tests I could see the lasers clearly from over a mile from my home the green being the most visible by far I would think the 50mW green would be the ideal power ratting for us.
the lasers are very powerful that we have used in fact I also used them to burst balloons just by pointing the 100mW green at them but as a serious rescue aid I would not be without one now.
With a flare it lasts just a few seconds and its gone if nobody is looking at the time you fire it it’s not helped you at all but with a laser you would get many hours of continuous use of the beacon to try to attract someone’s attention which gives you a better chance of rescue
Once again a massive thanks to Paul from www.megagreen.co.uk/index.asp for all his help
just to add a quick note the lasers were also very visable in daylight it was just easyer to photograph them in the dark

[THURSOMAN]

Well done Terry!
What a super review.
I have to admit that despite the fact I was initially dubious about these lasers I am very impressed indeed.
As you say the only disadvantage being it is not recognised as distress signal.
However even if it never does surely these lasers are an extremely effective way to direct a resuers attention to us assuming we have called a distress call using our VHF.
Perhaps informing our local coastguard we have these lasers should we ever need to use them could be advantageous.
Maybe we could add this to our CG66???

So does the 50mW seem to shoot up as far as the others Terry?
Also do the green ones still seem to be more effective than the red in daylight?
Lol I may be tempted if I got one to go for the 100mW simply to bust balloons. ;D ;D ;D ;D ;D

Thanks very much indeed for the time and effort involved here Terry.
You've converted me for sure.

Chris

[ZEBRA]

the green is 100 times more visible than the red even in daylight i think it would be a very clever idea to add them to the cg66 form .
all the sizes seam to go on for ever they seam to reach the same distance the only thing i would say is the more powerful the thicker the beam the 50 i think is an ideal size for us but i must admit the 100 was great fun bursting balloons and burning through cd cases ;D.
on one of the nights i photographed the lasers i had 3 of the local police men turn up to see what was going on they were amazed at how visible they were they had seen them from quite a way off and came to see what was going on so i would think using one at sea would also attract someone to call the coastguard they had exactly the right effect in that someone seen them and came to investigate what they were .
i think in time they will be recognized as a distress signal i know if i was looking out to sea and seen a green wand like light flashing out there that seamed to be signaling i would call the coastguard .

[THURSOMAN]

That is good news you attracted the police Terry.
Testiment to the effectiveness of attracting attention for sure.
Brilliant stuff

Saving up for one now.

[curly]

How much do these lasers retail for Terry?

[ZEBRA]

hi curly i think the 50mW is £120 the higher the power the more they cost but the nice thing is your only buying it once thers no expiry on them and they come with rechargable battery and charger so its only a one off purchase i think my flares were £69.00 and they need replacing every 2 years and if i fired them all it would last for 121 seconds.
what really made me think was the fact that we cant test flares so have no way to know if they are working or not i have had quite a few not fire granted they were just out of date but they never worked with a laser you can test it out as much as you like and know it will work when you need it and they are visable for as long as you have them switched on for could be 2/3 hours to get rescued but your always visable .
i also liked also the fact that they are small enought to put in your pfd so should you fall in and be away from your boat you can still use the laser while in the water aiding rescue should it be needed .

[JIMBOB]

Judging by the website these lasers appear to be for 'pointing' purposes only, astronomers etc etc. They are not advertised as flairs on the site, I don't think they will replace traditional pyrotechnic distress flairs to be honest. I do however like the idea of shooting balloons with them ;D

[kerny]

Impressive report Terry, maybe an advertising campaign over a period of time to educate the public into recognising lasers as distress signals would work, but I think that they would have to stick to the same colour and I think it would take some time.But the positive side is that if someone noticed a green laser waving about out at sea for some time that there would be a good chance of it being reported. Lets hope they don't use them at football matches , eg to point at beach balls at Anfield l.o.l.

[BUDDY]

In the wrong hands these could be devastatingly dangerous.

In the right hands they could be life savers.
When first chatting about these i had my reservations. They are very bright and can be seen for miles, like the green one at blackpool. Its just a laser light racing across the sky. Would one being used as an sos flare be recognised as quick as a normal flare, i think not.
But if this is the way forward i think they will be an excellent bit of kit when people are more educated.
Until then i will take my taking my flares and VHF.
Steve

[JIMBOB]

The thing is Steve, why re-invent the wheel? I would sooner see EPIRBS's as the way forward instead of relying on gimmicks, which is what I see these laser pointers as. It's just another company attempting to emulate something which is already recognised and proven to work, at a cost which is probably vastly inflated. Call it a safety item and all of a sudden the price goes up. In relative terms, for a few bob more you could buy an Emergency Position Indicating Radio Beacon. This would be more conducive to a successful recsue than relying on somebody walking a dog, thinking they are getting a free laser show, to phone for help.

[ZEBRA]

this is what the search and rescue in america had to say about lasers in there 1999 conference
++++++++++++++++++++++++++++++
www.equipped.com/sar-americas99.htm#greatland

Many night time marine rescues are effected as a result of finding the survivors using searchlights which reflect off the retro-reflective material applied to most marine life rafts, life vests, and vessels. Without the retro-reflective material, which reflects light back to its source no matter from what direction it is coming, many of these survivors would never have been found. Even with 406 beacons to get SAR very nearly on top of a survivor, it can still be difficult to actually locate a survivor on a stormy sea at night. The problem is that the range of even the very high-powered searchlights on vessels is limited, the less powerful lights on aircraft even more so (though night vision devices used in airborne SAR help compensate a bit). Fog and poor weather conditions further inhibit the effectiveness of these lights to illuminate a survivor.

Now comes a potential solution in the form of the Greatland Laser LLC Rescue Laser Scanner (RLS). Originally developed as a better means of lighting runway centerlines, it turns out to be an extremely effective piece of SAR equipment. The handheld, 5 volt, battery powered 532nm diode laser sources is equipped with plano-convex (flat on one side and convex on the other) optical lenses.

In this design, the laser is not a pinpoint light source we normally associate with a laser, but rather a thin, expanding vertical line of green laser light. Swept across the surface horizontally, while the thin beam is held vertical, it covers a vast swath of area with each sweep, from near the point of origin to the far horizon. When it passes over a retro-reflective piece of material (or even any normally reflective material that is at the right angle or which is curved) it flashes very distinctively back at the laser source, much like a mirror flash. You can't miss it. The company claims that the reflected light from a 4 x 4 inch (10.16 cm) piece of retro-reflective material is visible from twice as far as a conventional searchlight from a vessel on the surface. From an aircraft at normal search altitudes using a 100mw RLS range would be in excess of four miles (even without night vision devices) and is eyesafe at 600 feet, or before it reaches the surface. The laser is also reportedly less affected by fog and poor weather than conventional searchlights which are severely effected. More powerful versions would have even greater range.

A smaller, less powerful, penlight sized handheld portable version of the SLR could be carried for ground to air signaling, in much the same way as a flashlight is used, but with far greater effect. In an infrared wavelength, it would also make a dandy covert signaling device for downed military pilots and crew.
The USCG has informally tested the SLR with positive feedback and Greatland is hoping to hear by September if their solicitation for funding of further testing and development of the technology is approved. The SLR seems to hold great promise for saving lives, as well as reducing SAR costs by hastening rescue. If eventually adopted, we would expect to see even more use of retro-reflective material as its effectiveness in conjunction with the laser will become an even greater contributor to survival.


reproduced article with permission

[JIMBOB]

What I can't grasp Terry is the difference between these... www.rescue-flares.co.uk/index.html ...and these... www.megagreen.co.uk/index.asp they seem to be totally different products. The recsue flares' beam is not visible. Whereas the magagreen ones are, and they look more like 'light sabres', also they are not advertised as safety flares on the website.

I just think that for such an important safety item, it's suitability should be absolutely 'bomb proof'.

I still like the idea of shooting balloons with them though you could see how far away you could hit a helium one ;D