Table of Contents
International Journal of Navigation and Observation
Volume 2008, Article ID 562878, 8 pages
Research Article

Precise Point Positioning for TAI Computation

Bureau International des Poids et Mesures, Pavillon de Breteuil, Sèvres Cedex 92312, France

Received 27 July 2007; Revised 19 October 2007; Accepted 27 November 2007

Academic Editor: Demetrios Matsakis

Copyright © 2008 Gérard Petit and Zhiheng Jiang. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


We discuss the use of some new time transfer techniques for computing TAI time links. Precise point positioning (PPP) uses GPS dual frequency carrier phase and code measurements to compute the link between a local clock and a reference time scale with the precision of the carrier phase and the accuracy of the code. The time link between any two stations can then be computed by a simple difference. We show that this technique is well adapted and has better short-term stability than other techniques used in TAI. We present a method of combining PPP and two-way time transfer that takes advantage of the qualities of each technique, and shows that it would bring significant improvement to TAI links.