Remote control rescue?

August 16, 2010 7:15 AM

Can the infrared light of a tv remote control be seen by airborne rescue personnel?

Could one use the infrared light beam from a tv or dvd player remote control to signal rescue personnel who are using infrared sensors?

posted by looknevada to science & nature (6 answers total)

Er, maybe? When the rash of webcam hacks for removing the IR filters came out awhile back, I gave it a go and was surprised just how 'bright' that little LED was. Whether it could be seen by an airborne rescuer, I've no idea. I imagine you'd have to aim it pretty well.
posted by jquinby at 7:23 AM on August 16, 2010

If you want to see how bright a TV remote is, just look at it using your cellphone camera. These things are diffuse, not directed, which is why it's often easier to change the channel by pointing the remote at the wall instead of the TV. It's not going to be visible from very far away.
posted by rlk at 7:25 AM on August 16, 2010

It's a bit of a stretch to say they could see such a small point of light on their IR monitors when flying at a few hundred feet. However, those IR LEDs do flash rapidly when you hold down a button, maybe it would be just enough to catch the rescuer's eye and make him/her want to investigate further. Maybe...
posted by Capa at 7:36 AM on August 16, 2010

You'd be better off with any LED flashlight. They emit both IR and visible light, so they'd be maximally visible.
posted by odinsdream at 8:21 AM on August 16, 2010

For the record, I have an Energizer Hard Case swivel light that features an infra-red beacon that is supposedly designed to be visible to responders using night vision, and when I've looked at it with said night vision, it's really not much brighter than the LED on the front of a TV remote, so I'd guess that yes, it would be visible to any low flying aircraft using the right equipment.

But a better question might be "would they be looking for that?" in a non-military context, are they going to be looking for military styled markers? They certainly might, but for my money, you'd be much better off using any kind of LED flashlight.

Something like the Photon Proton Pro might be more what you are looking for: it's very small, extremely bright, runs off of AA batteries that can be gotten anywhere, and most importantly, it has both a white and red light and those lights can be set to strobe a number of ways including SOS.

That, I suspect is exactly the kind of thing that an airborn responder would be looking for.
posted by quin at 12:53 PM on August 16, 2010

It depends on the ambient light around you. If you were in overcast darkness without any other sources of IR or visible light, they could see you with gen3 night vision equipment a quarter mile away. I base this on my experience with 940nm 60-degree beam angle remote control LEDs hooked to 3v batteries.

If you can get it to blink on and off once a second, it will be easier to discern amongst other sources of light. Having something that blinks three times, pauses, then repeats would be ideal from a rescue standpoint.

A regular visible light flashlight would be better, but if all you have is a remote...
posted by graftole at 7:53 AM on August 17, 2010