In the context of spaceflight, a satellite is an artificial object which has been intentionally placed into orbit. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as Earth's Moon.
Satellites are used for a large number of purposes. Common types include military and civilian Earth observation satellites, communications satellites, navigation satellites, weather satellites, and research satellites. Space stations and human spacecraft in orbit are also satellites. Satellite orbits vary greatly, depending on the purpose of the satellite, and are classified in a number of ways
SatNOGS (Satellite Networked Open Ground Station) project is a free software and open source hardware platform aimed to create a satellite ground station network. The scope of the project is to create a full stack of open technologies based on open standards, and the construction of a full ground station as a showcase of the stack.
In order to implement such a stack the four following different sub-projects are developed
SatNOGS Network is a web application for scheduling observations across the network of ground stations. It facilitates the coordination of satellite signal observations, and scheduling such observations among the satellite ground-stations connected on the network.
SatNOGS Database is a crowd-sourced application allowing its users to suggest satellite transmitter information for currently active satellites. Its data are available via an API or via a web application interface allowing other project to use its satellite transmitter information.
SatNOGS Client is the software to run on ground stations, usually on embedded systems, that receives the scheduled observations from the Network, receives the satellite transmission and sends it back to the Network web app.
SatNOGS Ground Station is an open source hardware ground station instrumentation with a rotator, antennas, electronics and connected to the Client. It is based on 3D printed components, readily available materials.