Title :
Working application of TWSTT for high precision remote synchronization
Author :
Koppang, Paul ; Wheeler, Paul
Author_Institution :
Datum Inc., Tuscaloosa, AL, USA
Abstract :
Two-way satellite time transfer (TWSTT) is the primary method implemented to determine the synchronization error between the United States Naval Observatory (USNO) Alternate Master Clock (AMC) located in Colorado and the USNO Master Clock located in Washington, DC. A hydrogen maser at the AMC is controlled to the USNO Master Clock within 1 ns RMS as determined by low noise (<300 ps) TWSTT measurements. A Kalman filter utilizes the TWSTT time difference data to give real time synchronization and syntonization error estimates that are used in a linear quadratic Gaussian control design. Calibration runs using a mobile earth station monitor the long term performance of the TWSTT method. Results of a closed loop TWSTT calibration experiment are discussed. Remote time difference data obtained via TWSTT and the GPS are compared
Keywords :
Global Positioning System; Kalman filters; calibration; clocks; computerised instrumentation; frequency control; frequency standards; measurement errors; measurement standards; real-time systems; synchronisation; telecommunication computing; telecontrol; time measurement; Alternate Master Clock; Colorado; GPS; Kalman filter; Naval Observatory; TWSTT; Two-way satellite time transfer; USNO Master Cloc; USNO Master Clock; United States; Washington; calibration; closed loop TWSTT calibration; high precision remote synchronization; hydrogen maser; linear quadratic Gaussian control; mobile earth station monitor; noise; real time synchronization; remote time difference data; synchronization error; syntonization error; Calibration; Clocks; Colored noise; Error correction; Hydrogen; Masers; Noise measurement; Observatories; Satellites; Synchronization;
Conference_Titel :
Frequency Control Symposium, 1998. Proceedings of the 1998 IEEE International
Conference_Location :
Pasadena, CA
Print_ISBN :
0-7803-4373-5
DOI :
10.1109/FREQ.1998.717916