According to known propagation of radio waves, and to existence of signals from area above the Equator that give us satellite TV program, I'd say they are real.
Knowing that if you move orientation of your dish for more than one degree makes you lose the signal, I'd also say that the signal comes from them.
According to night sky where many bright spots (called stars and planets) move, and some bright spots (called geostationary satellites) remain still, I'd also say they are real.
According to people, where some accept their existence and others deny them, I'd declare this last source of info unreliable.