Global Positioning System (GPS), officially NAVSTAR GPS, is a global navigation satellite system for positioning and timing. GPS tracking systems has been developed since the 1970s by the U.S. Department of Defense and replaced about 1985 the old satellite navigation system NNSS (transit) from the U.S. Navy, as the Vela satellites for detection of nuclear explosions. GPS is fully since the mid-1990s and is functioning since the closure of the artificial signal degradation (Selective Availability) in May 2000 for civilian purposes, location accuracy on the order of often better than 10 meters secure. The accuracy can be achieved by differential techniques (DGPS) increase in centimeters, for special applications in geodesy can be obtained even more accurate. GPS has established itself as the world’s most important detection method and is widely used in navigation systems.
The official name is “Navigational Satellite Timing and Ranging – Global Positioning System (NAVSTAR GPS). NAVSTAR is sometimes used as an abbreviation for “navigation system using timing and ranging”. GPS tracking was on 17 July 1995 was officially put into operation.
GPS was originally intended for positioning and navigation in the military (in weapon systems, warships, aircraft), etc.. One advantage is that GPS receivers receive signals only and not send. It can be navigated without the enemy gets information about their own location. Today, however, it is used increasingly in the civilian sector: maritime, aviation, by navigation systems in cars, for positioning and tracking in public transport/ vehicle tracking, for orientation in the outdoor area, surveying, etc. In agriculture there is the so-called Precision Farming on the location of machines used in the field. Similarly, GPS is now also used in competitive sports. Specially designed for use in mobile phones, the Assisted GPS (A-GPS) was developed.