Combination of TWSTFT and GNSS for accurate UTC time transfer

The international UTC/TAI time and frequency transfer network is based on two independent space techniques: Two-Way Satellite Time and Frequency Transfer (TWSTFT) and Global Navigation Satellite System (GNSS). The network is highly redundant. In fact, 28% of the national time laboratories, which contribute 88% of the total atomic clock weight and all the primary frequency standards to UTC/TAI, operate both techniques. This redundancy is not fully used in UTC/TAI generation. We propose a combination that keeps the advantages of TWSTFT and GNSS and offers a new and effective strategy to improve UTC/TAI in terms of accuracy, stability and robustness. We focus on the combination of two BIPM routine products, TWSTFT and GPS PPP (time transfer using the precise point positioning technique), but the proposed method can be used for any carrier phase-based GNSS product.

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

[2]  Demetrios Matsakis,et al.  The Accuracy of Two-Way Satellite Time Transfer Calibrations , 2005 .

[3]  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..

[4]  A. Bauch,et al.  On measurement noise in the European TWSTFT network , 2008, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[5]  D. Matsakis,et al.  GPS Carrier Phase Analysis Noise on the USNO-PTB Baselines , 2006, 2006 IEEE International Frequency Control Symposium and Exposition.

[6]  W. Lewandowski,et al.  Test of GLONASS precise-code time transfer , 2000 .

[7]  Pascale Defraigne,et al.  Combination of TWSTFT and GPS data for time transfer , 2010 .

[8]  Jan Vondrák,et al.  Combined smoothing method and its use in combining Earth orientation parameters measured by space techniques , 2000 .

[9]  W. Lewandowski,et al.  Use of GLONASS at the BIPM , 2009 .

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

[11]  Z Jiang.  Towards a TWSTFT network time transfer , 2008 .

[12]  Z. Jiang,et al.  Comparison and combination of TAI time links with continuous GPS carrier phase results , 2006, Proceedings of the 20th European Frequency and Time Forum.

[13]  Otto Koudelka,et al.  Time transfer with nanosecond accuracy for the realization of International Atomic Time , 2008 .

[14]  Gerard Petit,et al.  Comparison of GLONASS and GPS Time Transfers , 1992 .

[15]  Patrizia Tavella,et al.  The evaluation of uncertainties in [UTC − UTC(k)] , 2006 .

[16]  Gerard Petit,et al.  Precise Point Positioning for TAI Computation , 2008 .

[17]  T.E. Parker,et al.  Sources of instabilities in two-way satellite time transfer , 2005, Proceedings of the 2005 IEEE International Frequency Control Symposium and Exposition, 2005..

[18]  W. Lewandowski,et al.  First Results from Glonass Common-View Time Comparisons Realized According to the BIPM International Schedule , 1996 .

[19]  Z. Jiang,et al.  BIPM comparison of time transfer techniques , 2005, Proceedings of the 2005 IEEE International Frequency Control Symposium and Exposition, 2005..

[20]  R. Wynands,et al.  First comparison of primary frequency standards between Europe and Asia , 2007, 2007 IEEE International Frequency Control Symposium Joint with the 21st European Frequency and Time Forum.

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