Title :
NIST-USNO time comparisons using two-way satellite time transfers
Author :
Howe, David A. ; Jespersen, J.L. ; Lombardi, Michael A. ; Klepczynski, W.J. ; Wheeler, P.J. ; Miranian, M. ; Powell, Walter ; Jeffries, J. ; Myers, Amanda
Author_Institution :
US Nat. Inst. of Stand. & Technol., Boulder, CO
fDate :
31 May-2 Jun 1989
Abstract :
Time comparison data between UTC US Naval Observatory (USNO) and UTC US National Institute of Standards and Technology (NIST) is presented along with some analysis of that data. Second-to-second raw difference data is white and with no discernible slope for a 300-s measurement; a simple mean is computed for the value of the time comparison. Long-term σy(τ) results are consistent with expected results of a comparison between NIST and USNO, and in-cabinet loop tests of the two-way satellite equipment point to system noise being a factor of 10 below the stability of these results. Therefore the noise contribution due to the two-way time transfer method is assumed to be negligible. The results show that the measurement time could be reduced from 300 s to 100 s with little or no compromise in precision even with a C/N0 as low as 55 dB-Hz
Keywords :
measurement standards; satellite relay systems; synchronisation; time measurement; 100 s; 300 s; NIST; NIST-USNO time comparisons; National Institute of Standards and Technology; US Naval Observatory; USNO; in-cabinet loop tests; measurement time; system noise; two-way satellite time transfers; Clocks; Delay; Extraterrestrial measurements; Modems; NIST; Regression analysis; Satellite ground stations; Spread spectrum communication; Testing; Time measurement;
Conference_Titel :
Frequency Control, 1989., Proceedings of the 43rd Annual Symposium on
Conference_Location :
Denver, CO
DOI :
10.1109/FREQ.1989.68864
