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How Satellites Work!
What is a satellite? A satellite is an object -natural or, man-made that goes around, or orbits, a larger object. The Moon is a natural satellite going around the Earth. There are hundreds of man-made satellites, also orbiting the Earth.
http://www.cybergeography.org/atlas/globalstar1.gif Modern Telecommunication Satellites: Communications satellites are spacecraft that beam radio signals around the world. Satellites are located all around the earth. They can fly as low as 200 miles above the earth’s surface or as high as 22,300 miles above. The higher the satellite is, the more area on the earth it can cover. Think of a flashlight; when you point the beam of light at a flat surface, the light gets more focused if you get closer and gets wider as you get further away. This is kind of like a satellite beam. The signals sent back to earth from the satellite are like light-beams from the flashlight. Have you used a satellite today? You use satellites everyday and probably don't even know it! Signals come from telephone calls, television programs and information sent and received from computers.
Satellites must have electricity to work, so they have large panels that gather power from the sun and convert it into electricity. Technology Terms: SONAR: Is an acronym for Sound Navigational and Ranging. A SONAR system emits ultrasonic signals by using underwater devices. A very sensitive microphone listens for these reflected pulses. Modern submarines rely on sonar for detecting the presence of enemy vessels.
RADAR Is an Acronym for Radio Detection And Ranging. A RADAR system involves the transmission of radio waves with a large antenna pointing in the desired direction. When these transmitted waves strike an object in the path of the beam, a tiny fraction of the radio energy reflects from the object, forming an echo signal. The antenna collects this echo energy and delivers it to the receiver. Through a computer processor the RADAR receiver can produce a visual signal on the screen as in television, or an audible signal as in telephone or radios.
Radio signals are sent from earth from huge dish-shaped antennas up to a satellite orbiting around the earth. When the signal gets there, it’s very weak because it’s traveled a LONG way.
Suggested Links: Too see the location of some Earth’s satellites http://www.profc.udec.cl/~gabriel/tutoriales/rsnote/cp5/5-12-1.gifTo lean how satellites are launched http://centaur.sstl.co.uk/SSHP/nano/ To view USA from a satellite http://www.space-technology.com/projects/satellites/satellites1.html Children Satellites’ Art http://grasse.obs-azur.fr/cerga/GMC/kids/gn/jdbcresp/jdbcresp1.html To view and artistic representation of a satellite http://www.space-technology.com/projects/satellites/satellites3.html To view antennas receiving signals. http://www.space-technology.com/projects/satellites/satellites2.html To learn more about how satellites work: http://www.gordon.army.mil/ocos/rdiv/FORKIDS/satswork.htm
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