Doppler Effect

The Doppler effect in satellite communications is the change in frequency of an electromagnetic signal that results from the relative speed of the satellite and the Earth terminal. When the orbital parameters of a satellite are known, Doppler shift can be used to determine the position of the Earth terminal. When an Earth terminal’s position is known, Doppler shift can be used to estimate the orbital parameters of a satellite. When the satellite (or the Earth station, or both) is moving quickly, the Doppler effect is an important consideration in satellite communications.