Use of Geodetic Receivers for TAI

P. Defraigne, G. Petit, C. Bruyninx

Abstract:	The classical time transfer method used to realize the TAI (Interriational Atomic Time) is based on the common-view technique, with GPS observations collected by C/A code receivers. The resulting clock offsets between the laboratory clock and GPS time are obtained from a fixed procedure defined by the CCTF (Consultative Committee for Time and Frequency). A similar procedure can be applied on the RINEX observation files produced by geodetic receivers driven by a stable external frequency. We propose here to modify the CCTF procedure for the links between geodetic receivers, in order to take advantage of the P codes available on Ll and L2. This new procedure forms the ionosphere-free combination of the PI and P2 codes as given by the 30-second RINEX observations files, the standard of the International GPS Service (IGS), and uses the satellite positions as deduced from the IGS rapid orbits. The procedure k tested using the Ashtech Z-XII3T geodetic receivers and the results are compared to those obtained with the classical CCTF procedure based on the C/A code. For short baselines, the Allan deviations up to IO days are equivalent, while there is an improvement of a factor 2 for the transatlantic time link.
Published in:	Proceedings of the 33th Annual Precise Time and Time Interval Systems and Applications Meeting November 27 - 27, 2001 Hyatt Regency Long Beach Long Beach, California
Pages:	341 - 348
Cite this article:	Defraigne, P., Petit, G., Bruyninx, C., "Use of Geodetic Receivers for TAI," Proceedings of the 33th Annual Precise Time and Time Interval Systems and Applications Meeting, Long Beach, California, November 2001, pp. 341-348.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In