[jp42]

"Those satellite photographs -- the landsat photographs -- are so darn good that when they re fully enhanced by computer, we can actually tell how high the waves are out in the middle of the Pacific; we can tell what the temperature of the ocean is 20 feet below.." - Grace Hopper in 1982 NSA lecture. YT link: https://www.youtube.com/watch?v=si9iqF5uTFk&t=1612s

I bet current spy satellite will be doing a lot things we can hardly imagine, may be we will know in 40-50 years down the line.

[Full_Clark]

There are a few open-literature papers already on how a submarine's wake might show up in analysis of surface patterns. Doesn't seem hard to imagine that the classified literature is a few steps ahead.