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So, what happens to the real television signal, the one with the great rainforest pictures, once it leaves the Amazon? Our earth station is especially designed to work with NASAs Advanced Communications Technologies Satellite (ACTS), which is in a geostationary orbit above the earth. Geostationary orbit means that the satellite is traveling around the earth at exactly the same speed the earth itself is spinning, and so, from the surface of the earth, it appears that the satellite is at a fixed point in the sky all the time. The satellite is located above the equator, near the central part of the Western Hemisphere, giving it a good view of both North and South America. Its view of this hemisphere is so good, in fact, that ACTS has been used to support communications experiments in places as far apart as Hawaii and Antarctica!
To contact ACTS, we have set up a large, solid antenna dish, about the size of a backyard TV dish. The dish is mounted on a heavy pedestal, and pointed to the spot in the sky where ACTS sits in orbit, 22,500 miles away. Much closer by, in an air conditioned room, there is audio and video equipment which takes the TV signals from each of the two cameras to be used, along with the additional phone lines, and compresses and combines all these signals into a single stream of ones and zeros. The stream of bits is encoded on to a radio carrier, which is then beamed up to the satellite.
The ACTS satellite is called the Switchboard in the Sky. Like a switchboard, the bits from our earth station are routed to their destination earth station, which happens to be the main ACTS control center at NASAs Lewis Research Center in Cleveland, Ohio. But the production facilities for Live from the Rainforest are located at MSU, which is a few states over from Ohio. No satellite is necessary, though, this time. LeRC is well connected into the U.S. phone network, as is MSU, and so a high-capacity, but otherwise ordinary, phone connection is established between the two sites. Thus video coming from the Amazon is immediately forwarded from Cleveland to Mississippi through the phone system as soon it is received from the satellite.
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