Atomic clock augmented global positioning system receivers and global positioning system incorporating same

Atomic clock augmented global positioning system receivers and global positioning system incorporating same

A GPS radio navigation system utilizes an atomic clock in each user's GPS receiver station and a ground reference station located at a fixed, precisely known position which determines GPS time from satellite information and transmits an absolute time signal together with time-of-flight information over a communications path of precisely known length to the user stations, each at a fixed position. Once the atomic clock in a GPS receiver has been set to the precise GPS time, the user station is free to maneuver for an extended period of time during which its position is calculated from pseudorange and time information received from as few as three satellites and the time maintained by its atomic clock. A global positioning system comprising: a plurality of satellites each repetitively transmitting signals indicating three dimensional satellite position information and time information; master station means for providing an absolute time reference and position reference to said satellites; ...