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APPENDIX
The Global Positioning System (GPS)
What is GPS?
The Global Positioning System is a constellation of satellites that provides a worldwide
locating and navigation service. Orbiting nearly 12,000 miles above the Earth, GPS
satellites circle the globe twice daily transmitting precise time and location information.
Using a GPS receiver, a user on Earth can pinpoint his exact location (latitude,
longitude and altitude) and navigate from point to point anywhere on the planet.
The complete system consists of 24 satellites and five ground stations. Constructed
over a period of twenty years, at a cost of over $10 billion, the system is operated free
of charge by the United States government. Although it was originally intended as a
worldwide positioning and navigation service for U.S. Armed Forces and other
authorized users, GPS now has a broad consumer and commercial application. Today
GPS helps steer cars, trucks, boats and planes around the world, and makes possible
such services as remote asset monitoring, fleet tracking, precision farming,
environmental analysis and a host of other positioning and navigation services.
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