1973 U.S. Air Force & Navy decided to develop asatellite navigation system.1974/79 System tests: Pseudolites and 11 Block I satellites1979 Decision to expand the GPS system to 24 satellites.1983 When a civilian airplane (Korean Airline) was shotdown after it had gone lost over Sovietterritory, it was decided to allow the civilian use of the GPS1989/94 replacement with improved Block II satellites1995 Full Operational Capability (FOC) is announced.2000 deactivation of the selective availability andtherefore improvement of the accuracy for civilians2005 Launch of the first 2R-M GPS-satellite.January 2006: 28 satellites (oldest one Feb. 1989)GPS - history
26.560 km from centre of earth- 6.360 km earth radius________20.200 km pathway-heightMEO - "medium earth orbit"GPS - functionalitytrue to scaleMonitor Stations - Hawaii
GPS - functionalityPosition DeterminationI am satellite X, myposition is Y and thisinformation was sentat time Z.distance
GPS - functionalityclock difference• Signals travel with the speed of light:c = 299 792 458,0 m/s• Time span between the satellite and thereceiver lies in the range of 0.07 sec.• A clock error of 1/100 second would lead toa mistake in the position of about?3000 km ! 2997924.58 m ;-)• To achieve an accuracy of 10 m of theposition, the runtime of the signal must beprecise to 0.00000003 seconds …
geocaching - equipment=> GPSr• Compass• Map• Cache Bag• PDA• Location• Stuff to Stash (trade)• Container (waterproof)• Micro-caches• Hiking Staff• special equipment like:scuba gear, things for climbing …
geocaching - conclusion• Find places you’ve never beenor recognised before.• Do outdoor sports with amission in background.• Enjoy the beautiful nature ...... and protect her!
chief source of informationGlobal Positioning System:http://en.wikipedia.org/wiki/Global_Positioning_Systemhttp://www.kowoma.de/en/gps/index.htmPictures and Art:http://www.deviantart.com/http://www.lockheedmartin.com/GPS/Geocaching:http://www.geocacher-u.com/http://www.geocache.at/http://www.geocaching.com/