Satellittilähetys

Satellittilähetys refers to the transmission of signals, such as television, radio, or data, via an artificial satellite orbiting Earth. This technology allows for broad geographical coverage, reaching areas that might be difficult or impossible to serve with terrestrial broadcasting. The process involves a ground station transmitting a signal up to a satellite, which then amplifies and re-transmits the signal back down to multiple receiving dishes or devices on Earth.

Satellites used for broadcasting are typically placed in geostationary orbit, which means they appear to remain fixed in the same position in the sky relative to a specific point on Earth. This fixed position simplifies the design of ground antennas, as they do not need to track the satellite's movement. Different frequency bands are used for satellite transmissions, with C-band and Ku-band being common for television broadcasting.

The advantages of satellite transmission include its ability to cover vast areas, including remote regions and oceans, and its resilience to terrestrial interference. It is crucial for services like direct-to-home (DTH) television, global internet access, and the distribution of television channels to cable operators. However, satellite transmission can be affected by weather conditions, particularly heavy rain, which can cause signal degradation. The initial cost of launching satellites and establishing ground infrastructure is also significant.