초록 ▼

An earth orbit satellite control system which provides automatic, continuous correction of phase and frequency in order to maintain synchronization between the satellite and a Global Positioning System (GPS). The system achieves phase and frequency synchronization by disciplining the satellite's ref

An earth orbit satellite control system which provides automatic, continuous correction of phase and frequency in order to maintain synchronization between the satellite and a Global Positioning System (GPS). The system achieves phase and frequency synchronization by disciplining the satellite's reference oscillator by phase locking it to timing pulses received from the GPS. The system comprising a state machine controller which cycles the disciplined oscillator into both a closed-loop operation wherein the oscillator is phase-locked to the GPS timing pulses, and an open-loop operation wherein a previously stored GPS timing pulse, or commands from a ground station, drive oscillator phase and frequency synchronization.

대표청구항 ▼

[ What is claimed is:] [1.] A method for synchronizing an earth orbit satellite to a Global Positioning System (GPS), comprising the steps of:receiving a reference timing pulse from the GPS;phase locking a reference oscillator of the satellite to the received GPS reference timing pulse; andcontinuou

[ What is claimed is:] [1.] A method for synchronizing an earth orbit satellite to a Global Positioning System (GPS), comprising the steps of:receiving a reference timing pulse from the GPS;phase locking a reference oscillator of the satellite to the received GPS reference timing pulse; andcontinuously and automatically correcting the phase and frequency of the reference oscillator in order to maintain synchronization between the satellite and the GPS;wherein the step of continuously and automatically correcting the reference oscillator is selectively modified based on commands from a terrestrial control system so as to employ at least one of a value stored on the satellite or a value transmitted from the terrestrial control system.