Need Help With a Stereo Antenna

I'm AFU now. :D
So you were talking about adding an FM antenna, and I said something like FM doesn't need to see the sky for it's signal and then was told GPS does.
I don't get it, because I know how they all work but I must be missing something in the translation I guess.

Never mind, carry on.:D
Satellite signals are direct line of sight, that's why you loose the signal when you go under overpasses. And I think the satellite signal bandwidth is different than the RF. Good dialogue please stay in the loop.
Ron