NAVSTAR: Global positioning system—Ten years later

With the award of one of the first multiyear procurements to be authorized by the Congress, the Department of Defense celebrates the tenth anniversary of a major Joint-Service / Agency program that promises to revolutionize the art and science of navigation. This contract, totaling 1.17 billion dollars, will result in delivery by the end of this decade of 28 satellites that are to become the heart of the NAVSTAR Global Positioning System (GPS). This paper traces the history of this program from its inception, identifying and discussing the major technologies that made it all possible. In so doing, the concept of operations of the entire system, including the satellites, their associated ground-based control network, and the family of user equipment being developed and tested to meet the broad scope of Department of Defence positioning and navigation requirements is introduced.