Green Survival laser

[ftumch33]

As I have a red survival laser from Greatland, I had an idea for a green, high powered survival laser ( I know their are green ones) with 3 modes. High powered so you can see the beam in bright conditions (think like 500 mw like the spider laser pointer), 3 modes, constant, SOS, and beacon that would greatly improve your chances of getting found in a survival situation with no duty cycle and water resistant.
Now my question would be is this possible? To have a laser with modes like a flashlight like this and someone here that could build it?
What do you guys think?

 

[sed6]

Survival laser, really?

lovecpf

 

[ftumch33]

actually it`s used as a signaling device if you`re stranded/lost

 

[Illum]

signal lasers are no different from regular lasers, only that the output is uncollimated. Its designed to hit something in the air as you point it about randomly towards incoming air traffic...

Now...pointing a regular laser at air traffic constitutes as a state felony already, so no...I don't think it would be a good idea at all...

I rather have just a flashlight [or one with an aspheric] with SOS/strobe than a laser

 

[Patriot]

I don't think a ollimated green laser is necessary since they're highly visible even when not directly hitting a target. The problem with green lasers is that they're a bit delicate. A hard shock can cause misalignment and render them inoperative.

In the case of emergency or survival (life and death) I would use a laser and ignore the legal ramifications.

To run a green laser semi-continuously as a beacon, you'd need a large power supply because they're hungry. The more powerful the laser, the greater inherent problem. The best way to use a laser wouldn't be passively but actively. You see a boat, car, plane (life and death) and actively get their attention with it, the same way you would with a pyrotechnic flare, signal fire, or signal mirror.

If you're looking for passive signaling, buy a good quality strobe light that operates on C or D cells.

I would just buy an 5mW greenie. They're inexpensive, compact, and reliable enough to be added to a signaling kit. You never want rely on a single piece of hardware or knowledge to to save you. It's better to spend $150 on a full signaling arsenal than to spend $1500 on a single device that's known to be unreliable (as a survival tool). My kit consists of a green laser, a polycarb signal mirror w/site, a bright "throw" light, a small pen flare for maritime use, a 1D cell strobe light, and good signal fire knowledge.

Now if you just want a 500mW to have fun with, that's a different story.

 

[ftumch33]

`Now...pointing a regular laser at air traffic constitutes as a state felony already, so no...I don't think it would be a good idea at all...`

I was thinking of more along the lines of just having it pointing straight up, not at the actually airplane/rescue copter, etc.,etc.
Just have it pointing straight up would be more than enough with a high powered laser pointer for someone to see.
The red laser I have from greatland is supposed to be pointed at th aircraft. It`s not even a point but a red line that increases in length the farther the object you`re point it at is from you.

 

[Illum]

pointing straight up...ahh, like a beacon

hmm, it might be a good idea...but as stated earlier its a bit on the fragile side

 

[Monocrom]

If you're lost in the woods, would a laser with a green tint be the most useful?

 

[Illum]

If you're lost in the woods, would a laser with a green tint be the most useful?

it would certainly be the brightest...but in frigid mountain air there would be very little particles in the air to reflect the beam...

 

[Patriot]

The red laser I have from greatland is supposed to be pointed at th aircraft. It`s not even a point but a red line that increases in length the farther the object you`re point it at is from you.

The reason for that is because without the fan shaped beam it would be very difficult for a 5mW red laser to catch the eye's attention unless you happened to cross that 1/60th of a minute of angle beam directly across a person's line of sight. With a green laser it's only necessary to get close.

A 5mW greenie in dark skies would be enough to capture someone's attention. Again, it would make a poor passive beacon due to power consumption vs. power supply.

If it really came down to you dying or signaling an aircraft for help I can practically guarantee that you wouldn't be pointed it straight up in the air, in hopes that a potential rescuer would assume someone was in trouble just because there was some guy shining a laser, in what could be perceived as a random direction. If I was out in the back country, lying in a ditch with my femur sticking through my pants I'd be frantically shining it right at an aircraft until my batteries died or I did! Let's be real if we're going to assume "survival" as the title states. Obviously a flat tire on the outskirts of town wouldn't merit the same action.

 

[neal71]

The reason for that is because without the fan shaped beam it would be very difficult for a 5mW red laser to catch the eye's attention unless you happened to cross that 1/60th of a minute of angle beam directly across a person's line of sight. With a green laser it's only necessary to get close.

A 5mW greenie in dark skies would be enough to capture someone's attention. Again, it would make a poor passive beacon due to power consumption vs. power supply.

If it really came down to you dying or signaling an aircraft for help I can practically guarantee that you wouldn't be pointed it straight up in the air, in hopes that a potential rescuer would assume someone was in trouble just because there was some guy shining a laser, in what could be perceived as a random direction. If I was out in the back country, lying in a ditch with my femur sticking through my pants I'd be frantically shining it right at an aircraft until my batteries died or I did! Let's be real if we're going to assume "survival" as the title states. Obviously a flat tire on the outskirts of town wouldn't merit the same action.

I would completely agree, and just to touch on the felony thing, if you are lost in the back country, you will not be arrested or charged. When in a true survival situation certain laws are not enforced, but such strict regulations on this would actually be beneficial to you if you were lost. They would certainly alert the proper authorities.

 

[get-lit]

News flash... green lasers do not work well, if at all in cold temps. In freezing temps like I get around here they don't even turn on. They also can't handle impacts. They are not well suited as a survival tool.

 

[Patriot]

Good point about the temperature! The sensitivity to impact was also mentioned previously.

It also doesn't hurt to revisit the fact that survival doctrine instructs against placing all your eggs in one basket and any category. I.E. always carry more than one method of signaling, fire starting, cutting, etc. when you're in the back country or remote areas.

 

[DArklite]

A 5mW greenie would be fine to add to the survival kit, and +1 on Patriot's suggestion - definitely add a strobe, firestick (starter), signal flare and a throwy torch, mylar "blanket", multi-tool, etc.

As for it working in cold weather - the 2001 "Lighting of the Christmas Tree" in Seattle was "pre-lit" at the top by Craig ("The_LED_Museum") and it caused quite a commotion in the crowd (no one saw a green laser before that). It even made the local news broadcast afterwards It was below freezing that night too. I got mine right after that, and have used it without fail in freezing temps. In fact, I just changed out the original 2xAAA batts a few weeks ago, but I don't use it that much and haven't dropped it. Maybe they built 'em a little better back then but who knows :shrug:

 

[Benson]

signal lasers are no different from regular lasers, only that the output is uncollimated. Its designed to hit something in the air as you point it about randomly towards incoming air traffic...

Now...pointing a regular laser at air traffic constitutes as a state felony already, so no...I don't think it would be a good idea at all...

I wouldn't want to be the one selling a commercial laser designed to be pointed at aircraft, but I don't see it as a particularly bad idea to build one if you reserve it for your own use, and only shine it at aircraft in a genuine emergency....

I rather have just a flashlight [or one with an aspheric] with SOS/strobe than a laser

Me too -- the laser is dead weight when you're not in an emergency -- a good aspheric has at least some other utility. Make it a green flashlight if you really want to maximize efficiency -- still more useful, and I'd guess same ballpark efficacy in Cd/W, since LEDs are rather more efficient, but won't be as tightly collimated.

OTOH, you can sweep the sky with a fan-beam laser and paint planes you don't even know are there -- with a square aspheric beam, you will need to see a plane and aim directly at it, but you'll be able to use an SOS mode or even send code because you're not just sweeping it back and forth. So... Get both! lovecpf

 

[Sigman]

I wouldn't want to be the one selling a commercial laser designed to be pointed at aircraft, but I don't see it as a particularly bad idea to build one if you reserve it for your own use, and only shine it at aircraft in a genuine emergency....

Well they've been sold for almost 13 years now and have good reviews as well. I know these links are around these halls already...

 

[lasermaker]

You only have to watch the news to see how effective the laser signal is. Pranksters shining lasers at aircraft, usually from cities at night, were spotted immediately and arrested in record time, even with all the background lighting. How would that signal look coming from a dark ocean or mountainside and what would the headlines say if it was a family freezing to death in a car, a sailor clinging to the debris of his boat? Signaling an aircraft or vessel with a laser when it is NOT AN EMERGENCY like most of these incidents is no different than making a false MAYDAY call on a radio or dialing 911. To say it is illegal to shine a Green Laser Flare at aircraft is like saying it is illegal to talk on the radio or use a cell phone, it is just our best form of communication and sadly missing in the majority of rescue efforts. Sadly, flashlights and strobes are useless in a urban setting for emergency signaling as they do not stand out, you can see a Green or Red laser flare from downtown LA at night from the air, first time, every time.

 

[ftumch33]

They say it wasn`t practical or couldn`t be done but...
Muahaha!

http://www.lasergenetics.com/nd5-laser-designator.aspx

 

[Ragnarok]

If it was an actual emergency and I had a laser with me that could serve as a sigaling device, you bet I'd use it!

If I planned on carrying a laser for such an improbable event, I think I'd prefer to carry both green and red lasers. Red is supposed to be the color for emergency signaling (aerial flares, etc.).

Technically, the 473nm blue lasers would be better for sidelight/scattering in the atmosphere to make for a visible beam pointing back to your location, but they are currently too expensive for such use imo. The green lasers are sufficient for that if the viewer is at a shallow angle to the beam and looking toward the beam source.

R.

 

[wyager]

LPF person here.... First off, there are very few lasers that I would trust in an emergency. Green, as you said, is the most visible to the human eye, but when the temperature changes (if you are in a cold or hot environment) it can cause power fluctuations, and minor movements in the laser cavity which can cause the beam to be very divergent. The same goes for physical shock. You might want to go with one of the rayfoss.com waterproof lasers, they are cheap and powerful. No big deal in terms of loss if it breaks.

and @ragnarok, I think you are right to say that blue lasers are better for atmoshperic scattering, but I'm pretty sure the idea is to point it directly at the object for signaling so this could actually be a detriment, plus there is the cost factor.

IMO the best signalling device is a dedicated one. I own 2 flare pen kits. Let me compare the two:
The first, I got at cabellas. The launcher is plasic, ugly, and hard to operate. That said, the flares are very nice and I'm sure go very high up. I fired one at a hill (winter, so no fire danger) and the recoil was very impressive, so was the noise. I was deaf in my right ear for a couple hours. So hold this away from you. The flares are solid aluminum and sealed with some kind of resin to be waterproof.
The second is from tru-flare USA. I got the red launcher. It is all metal, I don't know if it's steel or aluminum. I LOVE the launcher, it's very small and easy to use, plus it looks great and could be used for a pen-gun project if you were so inclined. The flares are so-so, they are made of plastic and I don't think they are fully waterproof. However, I waterpoofed mine by taking of the cap, and putting some wax in the inside and then doing the same on the outside. I also waxed the outside of the primer. I HAVE NOT fired these yet, so I cannot really compare them to the cabellas one, but I don't think they would go as high. But as long as you are not under humongous trees or in a canyon you should be fine. The bearbanger rounds are sweet, it's a plastic orange thing longer than a flare, and when opened up it looks really cool. There is a sleek silver projectile that appears to have a small aperture that directs the jet of some solid rocket fuel (like in an estes motor) which leads to the explosive. These things are great for scaring the hell out of wildlife or daytime signaling.

So, in short, don't spend too much effort on a laser, rather go for a nice flare kit. I only own pens, but you might want to consider a 12 guage flare pistol (or just fire 12 guage flare rounds from a shotgun) or even one of those really cool surplus metal pistols that can fire exploding or smoke rounds too.

will