GLOBAL POSITIONING SYSTEM CONSTELLATION CLOCK PERFORMANCE

摘要

The Naval Research Laboratory (NRL) conducts comprehensive analyses of the Global Positioning System (GPS) atomic frequency standards under the sponsorship of the GPS Joint Program Office (JPO) and in cooperation with the 2nd Space Operations Squadron (2SOPS) at the Master Control Station (MCS) in Colorado Springs, Colorado. The purpose of the analyses is to determine the performance of the timing signals originating with the atomic frequency standards carried aboard the space vehicles. Metrics used in the analyses and presented in this paper include frequency, drift, and stability histories and stability profiles based on the Allan and Hadamard variances. Also presented in this paper are comparisons of performance based on the broadcast as well as the precise post-fit ephemerides.