Tuesday, November 25, 2008

What are satellites so important?-part 1 (3 of 9)

There exists a recent surge in demand of continually available up-to-the-minute information; so satellite-based telecommunications businesses, including, radio, television and telephony, have a huge potential commercial profit, especially to places where traditional cable isn’t feasible, leading to an increase in satellite communications. For example, DirecTV, a major satellite television company that was started in 1994, has 14 satellites in geosynchronous orbit, each costing hundreds of millions of dollars to construct and But there also exists a much wider variety of use with these communication satellites, which are used for direct-to-home television channels and packages, broadcast feeds to and from television networks and local member stations, distance education by schools and universities, business television, videoconferencing, and to distribute national cable channels (such as ESPN, CNN, or HBO) to the cable TV receiver and satellite TV stations. Satellites are also used to distribute satellite radio, sending digital radio streams across the entire continental US, and satellite telephony, a necessity in extremely isolated areas, such as Mount Everest and the savannahs of Africa or other less exotic, but equally remote areas where cell phone towers do not reach or exist.
But satellites are also relied upon for GPS, a staple in modern American navigating, civil planning and scientific research. GPS, or Global Positioning System (the nickname of the U.S. NAVSTAR Global Navigation Satellite System (GNSS)), which is made of a network of 24 satellites in geosynchronous orbit, an orbit that allows a satellite to return to exactly the same place in the sky at exactly the same time each day, which allows continually transmitted time and position information that, used in a system of triangulation, allow one to find a receiver/transmitter’s precise location anywhere across the world. The recent and quite complete success and dependence upon the United States’ NAVSTAR GNSS also has inspired other countries to launch their own GNSS networks such as The European Union’s Galileo Positioning system, China’s COMPASS, Japan’s QZSS, India’s IRNSS and the restoration of Russia’s GLONASS. GNSS, along with aerial pictures from weather or other earth-observing satellites, is responsible for the recent jump in information about the world and the infamous Google Maps and similar programs, and allowing for a precise time reference (atomic time) used in earth sciences and telecommunication networks, enhanced 911, more efficient search and rescue, in addition to the more precise and more rapid creation of geospatial information systems, which are used in navigation programs that tell you how far you might be to a place such as a restaurant or museum, for instance, but are used in various occupations such as: environmental impact evaluations, urban planning, criminology, history, sales and marketing.

No comments: