Use of Geodetic Receivers for TAI
Abstract
The classical time transfer method used to realize the TAI (International 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 L1 and L2. This new procedure forms the ionosphere-free combination of the P1 and P2 codes as given by the 30-second RINEX observation files, the standard of the international GPS Service (IGS), and uses the satellite positions as deduced from the IGS rapid orbits. The procedure is 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 10 days are equivalent, while there is an improvement of a factor 2 for the transatlantic time link.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2002
- Accession Number
- ADA485791
Entities
People
- C. Bruyninx
- G. Petit
- P. Defraigne