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geostationary earth orbiter (GEO)

In satellite communication, the altitude of the satellite as well as its orbit is an essential characteristic for the satellite service. According to the three altitude ranges, a distinction is made between GEO satellites, MEO satellites and LEO satell

ites. The satellites in geostationary orbit (GEO) are located at a distance of 35,786 km from the Earth's surface and 42,164 km from the center of the Earth. At this distance, the centrifugal force acting on the satellite is equal to the Earth's gravity. The speed is such that the orbital period of the satellite at the equator is exactly one day. In relation to the earth, geostationary satellites therefore appear as if they were "positioned" in a fixed position above the equator line. Since they have no relative motion to the Earth's rotation, they appear to be stationary. They are therefore also known as synchronous satellites. Unlike asynchronous satellites, which require the satellite antenna to track the satellite, synchronous satellites allow the parabolic antennas

to be permanently pointed at the satellite.

Satellite orbits and satellite services

Satellite orbits and satellite services

GEO satellites have a large footprint on the Earth's surface when their radiation is not focused on specific regional areas. To ensure that the exact same hotspot is always illuminated, special antennas are used that are adjusted accordingly as the satellite rotates. These antennas are called Despun antennas. Because of their exact beamwidth, GEO satellites are used for broadcasting services such as DVB Satellite (DVB-S) or Satellite DAB (S-DAB). They are unsuitable for telephone services, as the delay times to and from the satellite and the propagation times in the transmitting and receiving facilities can total up to 100 ms, thus negatively affecting voice communications

.

Overview of the different satellite orbits

Overview of the different satellite orbits

With only three GEO satellites, a global satellite network can already be established. GEO satellites such as Astra or Eutelsat are used for broadcast services, for the transmission of radio and television programs.

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Englisch: geostationary earth orbiter - GEO
Updated at: 03.03.2014
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