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

fYear

1989

fDate

31 May-2 Jun 1989

Firstpage

193

Lastpage

198

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 σ_y(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;

fLanguage

English

Publisher

ieee

Conference_Titel

Frequency Control, 1989., Proceedings of the 43rd Annual Symposium on

Conference_Location

Denver, CO

Type

conf

DOI

10.1109/FREQ.1989.68864

Filename

68864