GLOBAL POSITIONING SYSTEM CONSTELLATION CLOCK PERFORMANCE

摘要

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