A ground station, earth station, or earth terminal is defined as a terrestrial radio station designed for extra planetary telecommunication with spacecraft. It can be thought of as a constituting part of the ground segment of the spacecraft system.
For the SatNOGS project a ground station is piece of hardware and software that is used to receive satellite signals.
There are different types of ground stations but they can be grouped into one of two forms, either one with moveable antennas or one with static antennas. A ground station with moveable antennas makes use of multiple antennas that a rotator points towards and tracks satellites. The rotator can either be a commercial or SatNOGS type. More information can be found on the rotators page.
SatNOGS also make provision for non-rotator ground stations. These are typically simpler and rely on no moving parts but require an antenna that has a broad view of the sky. Typical installations tend to work well with higher passes but will struggle to achieve successful observations when satellites pass lower to the horizon.
In addition to the rotator is a receiver. The RTL-SDR dongle is typically used as a receiver and the Raspberry Pi is the integration between the ground station and SatNOGS network. Further information can be found in the receivers page
A receiver is then, in turn, connected to an antenna or antennas. The type of antenna used depends on the ground station. Different satellites will have different uplinks and downlinks and the choice of antenna will affect the observation. See the Antennas page for typical ground station set ups.
This wiki will focus on the SatNOGS ground station but it is worth noting that commercial rotators and commercial receivers have been used in some instances.