You raise an interesting question MJB. Go to:-
Axsys Technologies
...and click on ADEM demo. (Caution it take a while to load).
The clip is an experiment in IR, from a Cineflex MS2, that shows the use of a cell phone being spotted from 10,000' in an orbiting fixed wing.
I have SAR experience and thermal experience but none in NVG. I doubt that NVG would see that far?.....but of course zooming to a known target and scanning a large expanse of real estate for the lost and confused are two very different objectives.
I guess the follow on question is about how we change our operational techniques to accommodate and fully take advantage of the new technologies. First in isolation, and then as combined assets.
Cheers
JerryG