Introduction to the Global Positioning System
The Global Positioning System was developed in the 1970’s by the US military to exceed the limitations of prior navigation systems and was made fully operational in 1994. GPS provides two levels of service – Standard Positioning Service and Precise Positioning Service – and consists of three system segments – Space, Control and User. SPS is available to all GPS users while PPS, a highly accurate military positioning service, is only available by those authorized by the U.S. As such, the Space and Control segments are maintained, operated and developed by the U.S. Air Force. Basic info on how GPS works, as well as some history and its applications, can be found on this site.