Search and Rescue - Lasers and Signaling Devices

[fsardone]

Pilots and lasers don't mix. Really, they don't. This may surprise you but if a pilot feels in danger they will leave. I have been there for helivacs that did not activate, or RTBd for unfavorable or hazardous conditions when a critically injured person needed them. More than once.
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Correct.
No aircraft commander would endanger his craft and his crew if felt threathened. A partially impaired pilot or copilot would render the crew not mission ready and mandate an immediate RTB.
Beside a laser shining toward you will not be seen a bright spot on the sea surface but as a blinding flash very diffucult to be located.

 

[MichaelMc]

It was pointed out, by a pilot, that the proper laser technique is to point it upward and allow some wiggle to create a vertical beam or cone that is very visible. Not to shine it at the aircraft or the horizon where the rescue or other aircraft might be.

I don't know the trade off in visibility strobe vs vertical laser.

A tool that can't be misused vs a tool that can is also a factor. Depending on one's judgement about the user's capability in that regard.

 

[-JD-]

How much more visible is a laser than a bright strobe?

So let's say that I don't have a green light that has a very small beam width, but instead I have a white light that is very intense. If I shine the white light in their eyes they come and the green light they don't? Hmmmm…..

M²

It as been pointed out, by a pilot, that the proper laser technique is to point it upward and perhaps wiggle it a bit to create a vertical beam or cone that is very visible. Not to shine it at the aircraft or the horizon where the rescue or other aircraft might be.

I do not know the trade off in visibility strobe vs laser.

A strobe radiating like a point-source and loses power (to an observer) proportional to the distance squared, as the energy spreads out in an expanding sphere. So if it is X bright at 1m, it is X/4 at 2m, X/9 at 3m, ... X/10,000 at 100m, .... X/1,000,000 at 1Km .... Atmospheric interference will make it worse, a little or a lot depending on conditions. Think clear, haze, then pea-soup fog. Now human vision is somewhat logarithmic, so we perceive the loss to be less, but it still goes down by a massive amount as we get further away.

A laser's power incidence is much more complicated (I saw forum discussions about the differing opinions that rival SB debates on pony bottles), but suffice it to say that a well collimated beam of light will spread very little in ideal conditions over a very long distance, to deliver its power in a concentrated area. So yea, pupil sized at multi-Km distances. Atmospheric disturbances, will definitely act to scatter the light and reduce its incident power. Actually, without the atmospheric scattering, you wouldn't be able to see the beam form the side. That is where the "point it upward and perhaps wiggle it a bit to create a vertical beam or cone" comes in. If there is the right balance of scattering, the beam can still punch through a long distance, but becomes visible from the side.

 

[Dan]

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A ScubaBoard Staff Message...

This thread was spun off from Search and Rescue - Scubaboard Staff Member - Northernone - Missing in Cozumel

It's too interesting, and too off topic, to be left there.

Thank you for your posts in this interesting topic.
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For those who choose to recreate in places where the funding for SAR is just not there, it pays to be prepared and have equipment and a plan in place for these type of contingencies. I have recreated all over the world, and have never needed a SAR response, but I do make sure I pack the extra weight for contingencies. My favorite beacon is an IR beacon that runs on a 9v battery. Fits in my pocket, and I can tell you, I'll be adding it to my dive kit in a waterproof submersible container.

Would you tell more about this 9v battery powered IR beacon?
What are the specification?
Where can we get it?
What kind of emergency message would it transmit?
What kind of receiver would SAR team need to have to be able to receive the message?

Thanks
Dan

 

[Scuba Cobra]

Would you tell more about this 9v battery powered IR beacon?
What are the specification?
Where can we get it?
What kind of emergency message would it transmit?
What kind of receiver would SAR team need to have to be able to receive the message?

Thanks
Dan

Phoenix Jr. Infrared Beacon – Tactical Night Vision Company

I do not use this exact model, but I use a very similar (cheaper) model for work on my helmet for IFF purposes. It just snaps right onto the battery and provides 96 hours of strobe. It can be seen very far through NVD's. nothing you need to do as SAR will have the necessary assets to see it.

 

[JXT71]

So let's say that I don't have a green light that has a very small beam width, but instead I have a white light that is very intense. If I shine the white light in their eyes they come and the green light they don't? Hmmmm…..

M²

Sounds strange, but consider this: I have been instructed directly by pilots to use a signal mirror to mark my location. On the other hand -during a SAR aviation awareness class - I have been instructed to not use a laser to signal my location. "Intense white light" like a spotlight or military-grade high beam are also not recommended.

 

[Dan]

Phoenix Jr. Infrared Beacon – Tactical Night Vision Company

I do not use this exact model, but I use a very similar (cheaper) model for work on my helmet for IFF purposes. It just snaps right onto the battery and provides 96 hours of strobe. It can be seen very far through NVD's. nothing you need to do as SAR will have the necessary assets to see it.

Cool! Thanks!

I may have room in my waterproof pouch to put this little gadget in.

I guess the pilots need to look down to the sea with night vision device.

 

[Scuba Cobra]

"Intense white light" like a spotlight or military-grade high beam are also not recommended.

Because they make you look like a reflection of the sun/ moon/ lights in distance.

signal mirrors, strobes, and fluorescent green dye packs and pen flares are pretty much your best bets for recovery at sea. all 3 of these can also be vacuum sealed into a small package that fits in your pockets

 

[Hoag]

Question for all the people who are advocating in favor of using a laser to point at a pilot: Have any of you had any real training in Land, Sea or even Arctic Survival (more realistic than what you might get in Boy Scouts) or conversely, have you ever had any training as either a pilot or as a SAR Observer?

 

[wgw04024]

Let's say the plane is 2 miles away from the victim with the laser in the water. That person flashes the laser at the plane with a quick pass. I don't know how to calculate the time the laser would be pointed at the plane, but it would be VERY small I would imagine. Once the plane saw it, diverted course, the victim would not have any reason to continue to point it at the plane.