Global Positioning System (GPS)--consists of a network of satellites linked together to pinpoint locations on the planet. GPS Navigation Devices--produced by Magellan, Garmin, TomTom, Nextar, and others with applications for the iPhone--allow almost everyone to take advantage of the GPS to navigate from place to place using maps. Multiple users can even find each other using two GPS navigation units. Many of these (like the iPhone) are hand-held devices and, while they may be used in vehicles, they can also be used by pedestrians.
The Astrolabe and the Mariner's astrolabe allowed ancient astronomers and navigators to determine positioning using triangulation. The GPS of today brings this process to pinpoint accuracy.
Wednesday, November 18, 2009
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