There are wavelengths other than visible light that satellites use.

Yeah, and which of those go through rain? The atmosphere blocks lots of wavelengths outside of visible light. Rain fade is huge above 11 GHz. Good luck imaging a person from orbit at a low RF frequency.

http://www.geo.mtu.edu/~scarn/teaching/GE4250/transmission_l...

https://en.wikipedia.org/wiki/Rain_fade