What is Global Positioning System

Artist's conception of GPS Block II-F satellite Automotive navigation system in a taxicab.
in Earth orbit

The Global Positioning System (GPS) is a space-based satellite navigation system that
provides location and time information in all weather, anywhere on or near the Earth, where there
is an unobstructed line of sight to four or more GPS satellites. It is maintained by the United States
government and is freely accessible to anyone with a GPS receiver.
The GPS program provides critical capabilities to military, civil and commercial users
around the world. In addition, GPS is the backbone for modernizing the global air traffic system.
The GPS project was developed in 1973 to overcome the limitations of previous navigation
systems, integrating ideas from several predecessors, including a number of classified engineering
design studies from the 1960s. GPS was created and realized by the U.S. Department of Defense
(DoD) and was originally run with 24 satellites. It became fully operational in 1994.
While originally a military project, GPS is considered a dual-use technology, meaning it
has significant military and civilian applications.
GPS has become a widely deployed and useful tool for commerce, scientific uses, tracking,
and surveillance. GPS's accurate time facilitates everyday activities such as banking, mobile phone
operations, and even the control of power grids by allowing well synchronized hand-off switching