Use of Rubidium GPS Receiver Clocks to Enhance Accuracy of Absolute and Relative Navigation and Time Transfer for LEO Space Vehicles

摘要

Utilizing high-stability clocks in GPS navigators enhances the accuracy of time estimates by allowing long-term averaging of time errors. The enhanced accuracy of time estimates in turn enhances the performance in positioning because the geometric dilution of precision is less when time is known than when time is unknown. This paper examines the enhancement in performance in estimation of position and time by utilizing a high quality rubidium oscillator in place of a high quality crystal oscillator associated with each of two GPS receivers. The two receivers are used for absolute and relative navigation and time transfer for two space vehicles in similar low-earth orbits. Substantial improvements in performance are achieved in estimation of absolute position, absolute time, absolute position, and relative time, but not in relative position, through the use of the rubidium oscillators.