Navstar orbits (GPS V1.0)

The global positioning system, better known by the acronym GPS ( global positioning system ), is a satellite navigation system that provides a mobile receiving device with its position, as well as the time, under any weather conditions, at any time. and anywhere on Earth; as long as the receiver is in the field of view of three GPS satellites (four or more for greater accuracy). Two of these systems are in operation: the American GPS and the GLONASS (Russian version of the GPS). There are also two other systems in implementation: the European Union 's Galileo and Compass ( BeiDou ) Chinese . The American system is administered by the United States Government and operated by the US Department of Defense . At first, its use was exclusively military, later being released for free civilian use. The main contributing factor to this was the downing of Flight KAL 007 in 1983, when it mistakenly entered USSR airspace and was then shot down by Soviet fighter jets. [ 1 ]However, it is believed that, in a war context, its civilian function would be revoked so that the device returns to being a military device. This would compromise the functionality of the GPS for the daily life of ordinary people, since the global positioning system, in addition to being used in general and commercial aviation and maritime navigation, is also used by several people to move around neighborhoods and cities, and especially, for travel. (Wikipedia)