There are over 300 geostationary satellites orbiting Earth.
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In the information age, people expect their television to be fast. Satellite television operates at fast speeds, traveling more than 20,000 miles in less than the blink of an eye. And while the concepts behind satellite television transmission are easy to grasp, the science and technology behind them are complex. Still, a few key principles stand out.
Geostationary Satellites
Satellite television uses geostationary satellites orbiting around Earth in order to transmit signals across the globe. These satellites are also known as geosynchronous satellites, and they feature a regularized orbit -- that is, the orbit in a fixed trajectory at all times. With this fixed trajectory, these satellites cover a consistent and limited range. These satellites do not have to be tracked by receivers on Earth, since they remain in a more or less fixed position.
Transponders
Geostationary satellites each feature transponders -- the larger the satellite, and the more functions it is responsible for, the more transponders it will feature. The role of these components is to carry the signal that is sent to the satellite back to Earth. To do this, transponders use radio bands of a particular frequency. Different functions -- such as radio, television or communications technology. For television signals, the C-Band or Ku-Band is usually used.
Dish Reception
Once signals have been sent to the satellite and re-routed toward Earth through the satellite's transponders, these signals must be received. That is the function of a satellite dish. Dishes vary in size, ranging from a mere 18 inches across to over 9 feet or more. The dish, which is concave, receives the signal and collects information, sending it to a feedhorn -- a piece of equipment that collects satellite data and sends it to be decoded.
Satellite Receivers
Once a satellite television signal is received by the dish and sent to the feedhorn, it must be decoded in order to be watched on a standard television. The feedhorn sends satellite information to a receiver box that is attached to the television. The receiver then converts it into the appropriate output for a television. Today, most television service providers encode their signals digitally and offer enhanced viewing options such as high definition.
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