18,519
edits
Global Positioning System: Difference between revisions
From ScoutWiki, For Everyone, Everywhere involved with Scouting and Guiding...
m
Robot: Automated text replacement (-\[\[(United States Air Force)\]\] +\1)
m (Robot: Automated text replacement (-\[\[Surveying\|([\w|\s]*)\]\] +\1)) |
m (Robot: Automated text replacement (-\[\[(United States Air Force)\]\] +\1)) |
||
| Line 12: | Line 12: | ||
Since the first experimental satellite was launched in 1978, GPS has become an indispensable aid to [[navigation]] around the world, and an important tool for [[cartography|map-making]] and land surveying. GPS also provides a precise [[time transfer|time reference]] used in many applications including scientific study of [[earthquake]]s, and [[synchronization]] of telecommunications networks. | Since the first experimental satellite was launched in 1978, GPS has become an indispensable aid to [[navigation]] around the world, and an important tool for [[cartography|map-making]] and land surveying. GPS also provides a precise [[time transfer|time reference]] used in many applications including scientific study of [[earthquake]]s, and [[synchronization]] of telecommunications networks. | ||
Developed by the United States Department of Defense, it is officially named '''NAVSTAR GPS''' ('''NAV'''igation '''S'''atellite '''T'''iming '''A'''nd '''R'''anging '''G'''lobal '''P'''ositioning '''S'''ystem). The [[satellite constellation]] is managed by the | Developed by the United States Department of Defense, it is officially named '''NAVSTAR GPS''' ('''NAV'''igation '''S'''atellite '''T'''iming '''A'''nd '''R'''anging '''G'''lobal '''P'''ositioning '''S'''ystem). The [[satellite constellation]] is managed by the United States Air Force [[50th Space Wing]]. The cost of maintaining the system is approximately [[United States dollar|US$]]750 million per year,<ref name="GPS overview from JPO" /> including the replacement of aging satellites, and research and development. Despite this fact, GPS is free for civilian use as a [[public good]]. | ||
== Simplified method of operation == | == Simplified method of operation == | ||
| Line 34: | Line 34: | ||
==== Control segment ==== | ==== Control segment ==== | ||
The flight paths of the satellites are tracked by US Air Force monitoring stations in [[Hawaii]], [[Kwajalein]], [[Ascension Island]], [[Diego Garcia]], and [[Colorado Springs, Colorado]], along with monitor stations operated by the [[National Geospatial-Intelligence Agency]] (NGA).<ref>US Coast Guard [http://www.navcen.uscg.gov/gps/gps_news_090905.htm General GPS News 9-9-05]</ref> The tracking information is sent to the [[Air Force Space Command]]'s master control station at [[Schriever Air Force Base]], [[Colorado Springs, Colorado]], which is operated by the [[2d Space Operations Squadron]] (2 SOPS) of the | The flight paths of the satellites are tracked by US Air Force monitoring stations in [[Hawaii]], [[Kwajalein]], [[Ascension Island]], [[Diego Garcia]], and [[Colorado Springs, Colorado]], along with monitor stations operated by the [[National Geospatial-Intelligence Agency]] (NGA).<ref>US Coast Guard [http://www.navcen.uscg.gov/gps/gps_news_090905.htm General GPS News 9-9-05]</ref> The tracking information is sent to the [[Air Force Space Command]]'s master control station at [[Schriever Air Force Base]], [[Colorado Springs, Colorado]], which is operated by the [[2d Space Operations Squadron]] (2 SOPS) of the United States Air Force (USAF). 2 SOPS contacts each GPS satellite regularly with a navigational update (using the ground antennas at Ascension Island, Diego Garcia, Kwajalein, and Colorado Springs). These updates synchronize the atomic clocks on board the satellites to within one [[1 E-6 s|microsecond]] and adjust the [[ephemeris]] of each satellite's internal orbital model. The updates are created by a [[Kalman Filter]] which uses inputs from the ground monitoring stations, [[space weather]] information, and other various inputs.<ref>[[USNO]]. [http://tycho.usno.navy.mil/gpsinfo.html NAVSTAR Global Positioning System]. Accessed [[May 14]], [[2006]].</ref> | ||
[[Image:GPS Receivers.jpg|thumb|left|GPS receivers come in a variety of formats, from devices integrated into cars, phones, and watches, to dedicated devices such those shown here from manufacturers Trimble, Garmin and Leica (left to right).]] | [[Image:GPS Receivers.jpg|thumb|left|GPS receivers come in a variety of formats, from devices integrated into cars, phones, and watches, to dedicated devices such those shown here from manufacturers Trimble, Garmin and Leica (left to right).]] | ||
