This entry was posted on Monday, August 17th, 2009 at 8:07 am and is filed under handheld GPS. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
Global Positioning System (GPS)
, 08 17th, 2009The Global P
ositioning System (GPS) is a global navigation satellite system (GNSS) developed by the United States Department of Defense and managed by the United States Air Force 50th Space Wing. It is the only fully functional GNSS in the world. It can be used freely by anyone, unless the system is technically restricted. These restrictions can be applied to specific regions by the U.S. Department of Defense. GPS can be used almost anywhere near the earth, and is often used by civilians for navigation purposes. An unobstructed line of sight to four satellites is required for non-degraded performance. GPS horizontal position fixes are typically accurate to about 15 meters (50 ft). GPS uses a constellation of between 24 and 32 medium Earth orbit satellites that transmit precise radiowave signals, which allow GPS receivers to determine their current location, the time, and their velocity. Its official name is NAVSTAR GPS.
Since it became fully operational on April 27, 1995, GPS has become a widely used aid to navigation worldwide, and a useful tool for map-making, land surveying, commerce, scientific uses, tracking and surveillance, and hobbies such as geocaching. Also, the precise time reference is used in many applications including the scientific study of earthquakes and as a required time synchronization method for cellular network protocols such as the IS-95 standard for CDMA. This gives us the ability to have a large variety of handheld GPS products.
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