RichManJoe
U2 has a synthetic aperature radar (SAR) payload which sees through the clouds.
Synthetic Aperture Radar is wonderful. I worked on it in early days.
The problem with radar is that a very narrow beam requires a very large antenna.
Too large for an aircraft.
So a large aperture is "synthesised" by processing. This combines the returns from successive positions along track, to build a mathematically equivalent antenna hugely extended in the along track direction. This gives effectively an intensely narrow beam pointing out sideways, painting the entire surface below with across-track scan lines in very fine detail.
Works equally well for satellites.
It just so happens I was in the Nasa's JPL control room in 1978, and watched the very first image arrive from Seasat.
https://en.wikipedia.org/wiki/Seasat
Everyone present was gobsmacked by the quality of the images, with every individual ship (and even its wake, if I remember correctly) outstandingly clear.
This was much better than had been expected. This non-military satellite clearly had crushing military significance.
Three months later its catastrophic failure was announced. Those of us in the business had our doubts.