An earth station is a ground station of a satellite transmission
. It is either installed on the earth's surface or in the earth's atmosphere. In satellite transmission, the earth station is the ground segment from which communication to the space segment, the satellite, takes place. Such a ground station can be permanently installed, located at sea or in the air. It communicates with one or more satellites or reflective space bodies. An earth station receives, processes and transmits the satellite signals and operates the downlink and the uplink to and from the satellite that forms the space segment.