Normally, at high altitude above Earth's surface, there are stage separation of a rocket. If we consider unmanned rockets, at high altitudes, how does human operators of a rocket who are here on Earth control stage separation?. It is common sense, that human naked eye cannot clearly see the rocket at such high altitude, then how do they exactly control stage separation with precision from Earth itself without seeing anything directly from their naked eye? Do they use some kind of graphical sensors with longitudes and latitudes? Or do they use some kind of camera attached to the rocket?
My another question is, how do human control all the actions of the rocket wirelessly ?(I know this is a funny question, yet I want to understand how it works)? do they use some kind of invisible radiations to communicate with all the minute functional part of the rocket system?