How a Satellite Dish WorksWritten by Gary Davis
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The curved dish focuses incoming radio waves onto feed horn. The feed horn then passes signal onto receiving equipment. Ideally, there will be no obstructions, such as trees to interfere with signal from satellite to satellite dish. With no obstructions you receive a much clearer signal. Some systems are set up to receive signals from more than one satellite. A new dish design uses two or more horns to pick up different satellite signals. As beams from different satellites hit curved dish, they reflect at different angles so that one beam hits one of horns and another beam hits a different horn. The central element in feed horn is LNB (low noise blockdown converter) The LNB amplifies radio signal bouncing off dish and filters out noise (radio signals not carrying programming). The LNB passes amplified, filtered signal to satellite receiver inside viewer's house. A cable is run from satellite dish into house and then connects to satellite TV receiver (black box) thus completing connection.
Gary Davis is owner of Dish Network Satellite TV, has several years experience in the Satellite TV Industry and has written several articles on satellite TV.
| | Artificial Satellite TypesWritten by Gary Davis
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Navigation Satellites These satellites were of enormous help to transportation companies, especially transportation over water and through air. The US GPS satellites are in Low Earth Orbit (LEO) and can determine position with a precision of 1 cm (0.4 inch). However, that very precise positioning is available for military purposes only. For commercial use precision is less accurate. Navigation satellites are also used for distance measurements for instance between buildings. Weather Satellites Observing earth is task for weather satellites, and then especially what happens in atmosphere. Different kinds of cameras, like infrared and normal cameras are used to observe either same part of earth, from a geostationary orbit, or more closely from polar orbits to get more detailed pictures. These low orbit weather satellites focus more on study of atmosphere than on current weather it self. Military Satellites Very similar to weather satellites, military satellites are also used for observing earth. Generally with higher resolution cameras and instead of normal communications equipment, they use encryption as well. Sometimes these types of satellites have very different types of orbits. For instance a very elliptical orbit which brings satellite as far away from earth as moon and as close to earth that it shortly enters atmosphere, to get as close as possible to earth surface without falling back to earth. Probably many more tactics are used, but for obvious reasons, these are unknown. Scientific Satellites Observing earth for scientific purposes is also very good possible with satellites. Making maps with low polar orbits satellites for instance, but also measuring exact shape of earth, geological research, etc can all benefit greatly from scientific satellites. But scientific satellites are not just used for observing earth. The research of space benefits also from scientific satellites. For instance Hubble Satellite which actually is a huge telescope that orbits earth. Because Hubble telescope doesn’t have to “see” through atmosphere it can produce much clearer and detailed images than earth based telescopes.
Gary Davis is owner of Dish Network Satellite TV, has several years experience in the Satellite TV Industry and has written several articles on satellite TV.
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