As with radio or television itself, it is not necessary to understand thoroughly the electronics and physics of satellites in order to understand how they work. Operating a satellite system is a bit more complicated than turning on a television and changing the channel, but the concepts are not difficult to grasp.

Satellites are Earth-orbiting spacecraft that are used to relay radio frequency signals. They are normally powered by batteries and/or solar cells. Satellites operate on various frequency bands, and they carry voice, data, fax, audio, and video information. The focus of this entry will be on television news uses of satellites, so it will be more concerned with audio and video than with other types of transmissions.

The Uplink

All satellite transmissions (i.e., feeds) begin with an uplink, which is the Earth-based transmission station that sends a signal to the satellite...