Use of IGS products in TAI applications

The Bureau International des Poids et Mesures (BIPM) is in charge of producing International Atomic Time TAI. In this aim, it uses clock data from more than 60 laboratories spread worldwide. For two decades, GPS has been an essential tool to link these clocks, and products from the International GNSS Service (IGS) have been used to improve the quality of these time links since its creation in the early 1990s. This paper reviews the various interactions between the IGS and time activities at the BIPM, and shows that TAI has greatly benefited from IGS products so that their availability is now an essential need for the quality of TAI links. On the other hand, IGS has also benefited from introducing time laboratories equipped with highly stable clocks in its network of stations. In the future, similar products will be needed for an ensemble of satellite systems, starting with GLONASS and GALILEO. It will be a major challenge to the IGS to obtain a consistent set of products, particularly for what concerns satellite clocks and inter-system bias values.

[1]  J. Nawrocki,et al.  Recent progress in GLONASS time transfer , 2005, Proceedings of the 2005 IEEE International Frequency Control Symposium and Exposition, 2005..

[2]  P. Tavella,et al.  Experimental assessment of the time transfer capability of precise point positioning (PPP) , 2005, Proceedings of the 2005 IEEE International Frequency Control Symposium and Exposition, 2005..

[3]  Gerd Gendt,et al.  The International GPS Service: Celebrating the 10th anniversary and looking to the next decade , 2005 .

[4]  Per K. Enge,et al.  Global positioning system: signals, measurements, and performance [Book Review] , 2002, IEEE Aerospace and Electronic Systems Magazine.

[5]  Gerard Petit,et al.  GPS All in View time transfer for TAI computation , 2008 .

[6]  E. Powers,et al.  Absolute calibration of a geodetic time transfer system , 2005, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[7]  Jim R. Ray,et al.  Geodetic techniques for time and frequency comparisons using GPS phase and code measurements , 2005 .

[8]  Pascale Defraigne,et al.  Time transfer to TAI using geodetic receivers , 2003 .

[9]  N. Guyennon,et al.  PPP and Phase-only GPS Time and Frequency transfer , 2007, 2007 IEEE International Frequency Control Symposium Joint with the 21st European Frequency and Time Forum.

[10]  Z. Jiang,et al.  A comparison of GPS common-view time transfer to all-in-view , 2005, Proceedings of the 2005 IEEE International Frequency Control Symposium and Exposition, 2005..

[11]  Pierre Héroux,et al.  Precise Point Positioning Using IGS Orbit and Clock Products , 2001, GPS Solutions.

[12]  P. Defraigne,et al.  Calibration of dual frequency GPS receivers for TAI , 2006, Proceedings of the 20th European Frequency and Time Forum.

[13]  K. Senior,et al.  Developing an IGS time scale , 2001, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[14]  Z. Jiang,et al.  Precise Point Positioning for TAI computation , 2007, 2007 IEEE International Frequency Control Symposium Joint with the 21st European Frequency and Time Forum.

[15]  D. W. Allan,et al.  Accurate Time and Frequency Transfer During Common-View of a GPS Satellite , 1980 .

[16]  Blair Fonville,et al.  ACCOUNTING FOR TIMING BIASES BETWEEN GPS, MODERNIZED GPS, AND GALILEO SIGNALS , 2005 .

[17]  G. Petit,et al.  Stability and accuracy of GPS P3 TAI time links , 2004 .

[18]  D. Matsakis,et al.  On optimizing the configuration of time-transfer links used to generate TAI , 2006, Proceedings of the 20th European Frequency and Time Forum.

[19]  Zhiheng Jiang,et al.  Absolute Calibration of an Ashtech Z12-T GPS Receiver , 2001, GPS Solutions.

[20]  Jim R. Ray,et al.  IGS/BIPM pilot project: GPS carrier phase for time/frequency transfer and timescale formation , 2003 .

[21]  C. Bruyninx,et al.  On the link between GPS pseudorange noise and day-boundary discontinuities in geodetic time transfer solutions , 2007 .

[22]  Jim R. Ray,et al.  Comparison of instrumental and empirical station timing biases for a set of ashtech Z12T GPS receivers , 2004 .

[23]  David W. Allan,et al.  INTERNATIONAL REPORTS: Technical Directives for Standardization of GPS Time Receiver Software: to be implemented for improving the accuracy of GPS common-view time transfer , 1994 .

[24]  S. Schaer.  Mapping and predicting the Earth's ionosphere using the Global Positioning System. , 1999 .