The Doppler effect comes into play anytime two objects are moving relative
to each other.

Ham satellites often go up on one sideband and retransmit on the opposit
sideband to help counter this effect.


"Szczepan Bialek" wrote in message
...
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*