| Dictionary, Encyclopedia and Thesaurus - The Free Dictionary 3,898,005,107 visitors served. |
Dictionary/ thesaurus | Medical dictionary | Legal dictionary | Financial dictionary | Acronyms | Idioms | Encyclopedia | Wikipedia encyclopedia | ? |
earth station |
Also found in: Dictionary/thesaurus, Wikipedia | 0.01 sec. |
|
|
earth station A ground-based receiving or transmitting/receiving station in a satellite communications system. The counterpart to the earth station is the satellite in orbit, which is the "space station." Earth stations use dish-shaped antennas, the diameters of which can be under two feet for satellite TV to as large as fifty feet for satellite operators. Antennas for space exploration have diameters reaching a hundred feet.Multiplex, Modulate and Upconvert An earth station is generally made up of a multiplexor, a modem, up and downconverters, a high power amplifier (HPA) and a low noise amplifier (LNA). Almost all transmission to satellites is digital, and the digital data streams are combined in a multiplexor and fed to a modem that modulates a carrier frequency in the 50 to 180 MHz range. An upconverter bumps the carrier into the gigahertz range, which goes to the HPA and dish. Downconvert, Demodulate and Demultiplex For receiving, the LNA boosts the signals to the downconverter, which lowers the frequency and sends it to the modem. The modem demodulates the carrier, and the digital output goes to the demultiplexing device and then to its destinations. See earth station on board vessel and base station.
earth station [′ərth ‚stā·shən] (communications) A facility with a land-based antenna used to transmit and receive information to and from a communications satellite. Want to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit the webmaster's page for free fun content. |
|
| Encyclopedia |
| Free Tools: |
For surfers:
Free toolbar & extensions |
Word of the Day |
Help
For webmasters: Free content | Linking | Lookup box | Double-click lookup |
|---|