What Is the Navstar GPS System?

In 1940, the United States government proposed the development of a global positioning and navigation satellite system. This led to the eventual implementation of the Navstar GPS system, a network of satellites that was built to provide navigation information to military forces worldwide.

After the initial government proposal in 1940 to develop a global positioning system (GPS) for navigation, different generations of test satellites were built to test, hone and ultimately comprise the system. These four GPS satellite systems were called the Block I, Block II/IIA and Block IIR. The first, Block I, system of satellites were a test batch, used to learn of any faults or improvements needed in the system principles that were then improved upon. The second, Block II and IIA, system was then deployed to make up the first actual official Navstar GPS system. Since this system is currently reaching the end of its working lifetime, a third system, Block IIR, is scheduled to go up as a replacement. When needed, a fourth generation, Block IIF, GPS system will be implemented.

The Navstar GPS system network of satellites is officially operated by the United States Air Force. Its ultimate role is to provide incredibly accurate navigation information to the military worldwide. However, with the advent of advanced technology in everyday civilian use, the same network is also in use for an increasing number of commercial products, such as car GPS systems, WiFi, Internet and smartphone applications.

Aside from the orbiting satellites, the Navstar GPS system is also comprised of five land based monitoring stations located in Hawaii, Kwajalein, Ascension Island, Diego Garcia and Colorado Springs. Ascension Island, Diego Garcia and Kwajalein are also the locations of three ground antennas. There is a master control station in Colorado's Schriever Air Force Base with the main office located at the Los Angeles Air Force Base.