Question about Night Vision

[belial.1980]

Hi,

Quick question on night vision for military application. I reviewed this post http://www.jimbutcheronline.com/bb/index.php/topic,16604.msg763855.html#msg763855 and it's a little similar. I didn't quite find the answer I was looking for, though, after reviewing this question.

Basically I have a group of modern PMC agents/mercenaries/soliders of fortune that are infiltrating a hidden underground fortress/temple. They're specialized in combatting supernatural threats and have been hired by 2 magi to help them recover the Ancient Hidden Secret Thingamajig^TM in said temple.

What kind of nightvision would be most applicable in this scenario? IR? Thermal? If I understand things correctly passive nightvision amplifies ambient light and I think ambient natural light would be negligible.
Specifically, the Magi and mercs crawl through an 18 inch crevice for 300 meters before the tunnel opens into a huge cavern that houses the temple. The magi will see through magical means but the soldiers will have to get by with modern military technology. Any thoughts? Thanks in advance!

[Aakaakaak]

military rarely use heat vision. Mostly they use ambient light. You can pick things up pretty good with it in almost no light.

[Fyrchick]

FLIR
There are flares and signal lights that are keyed for just the IR spectrum so only troops with using it can see.

We use it all the time in all kinds of conditions. The older ones are just B&W but the new ones are color and very pretty. 

The typical "night-vision" that is usually in a green display is also still used although it is limited. There are some systems/equipment that allow you to switch functions depending on the range and type of thing you are looking for/at. The military and firefighters have HUD or eyepieces on their helmets that use FLIR.

[belial.1980]

FLIR
There are flares and signal lights that are keyed for just the IR spectrum so only troops with using it can see.

We use it all the time in all kinds of conditions. The older ones are just B&W but the new ones are color and very pretty. 

Thanks for your input! So, how are these flares and signal lights normally deployed? Would somebody carry the lights/lit flares? Or would they toss the flares ahead into darkened areas? 

[Fyrchick]

mm.. I need to clarify. I said flares when what I was seeing in my distracted brain were the signal markers.. like the little flashing lights that you use to set up a landing zone or what have you.

http://www.tek-tite.com/src/products.php?c=2092

...kind of like those. We have these little strobes that we can change the lens colors for whatever purpose and we get ads all the time for the IR ones.

(I see there ARE IR flares tho.... http://www.drdo.org/pub/techfocus/feb04/infrared.htm 
cool)

Anyway, we use the signal strobes for search and rescue and the little scene lights to set up landing zones. The strobes we have on the marine unit PFD's in case someone goes overboard at night. They are these little clip-on thingy's that automatically activate in water.

I can say that a thermal imaging camera can be very precise depending on the camera and the user. You can tell the difference between hot air and ambient temps, see wet footprints on the ground if the temp difference is great enough and see signatures through walls. Its very awesome.

Anyway, hope this helps.


^{edited for obvious non-editing in the original post...}

[belial.1980]

Awesome. Thank you so much for your help! 

[KevinEvans]

Most of the IR goggles I have used also have an IR emitting diode for no ambient IR conditions. We racked up a goodly number of kills by waiting for the other guys to turn on thier diode and thus give away thier position....

Regards,
Kevin