Szczepan Bialek wrote:
You all know that the frequency from a satellite is changing.

Does anybody know if the frequency from a spacecraft reacts on the orbital
speed of the Earth.
S*

No, what you hear is mainly due to the orbital speed of the
satellite around the earth. The satellite has a speed relative
to the observer, and the resulting doppler shift makes the apparent
frequency of the satellite change.

When using a linear transponder, the situation becomes more complex
because both the speed relative to the transmitter and the speed relative
to the receiver have to be taken into account.