International Journal of Navigation and Observation 
Volume 2008 (2008), Article ID 562878, 8 pages
doi:10.1155/2008/562878
Research Article

Precise Point Positioning for TAI Computation

Gérard Petit and Zhiheng Jiang

 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

Recommended by Demetrios Matsakis

Abstract

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.