The GNSS solution named ’GT2’ is produced by the German Research Centre for Geosciences (GFZ) for the International GNSS Service (IGS) working group TIGA. It contains position time series for 757 permanent GNSS stations expressed in the ITRF2014 reference frame over the period January 1994 to December 2015.

This GNSS solution was carried out within the framework of the 2nd IGS reanalysis (reprocessing) campaign (Repro2). Among the 757 stations processed by GFZ, as many as 538 have actually been identified as co-located, or nearby, tide gauges.

The GNSS velocities, provided here for 579 stations (nearby tide gauges and reference frame stations included) with a minimum record length of 3 years and data gaps not exceeding 30%, are also produced by GFZ. To be more realistic, constant values (0.1 mm/yr in horizontal and 0.3 mm/yr in vertical) have been added to the formal errors on the velocities.

More details about the GNSS data analysis strategy can be found in Deng et al. (2015).


 Vertical velocities table

The GT2_Vertical-Velocities_Table provides the vertical GPS velocities and uncertainties from the 593 stations fulfilling the criteria of 3 years of minimum length and data gaps not exceeding 30%, estimated by the GFZ group.

 Daily time series

The file contains individual station data files of daily position time series in ITRF2014 with respect to the position at the mid time series epoch. These positions are expressed in meters in the local frame (North, East, and Up). The reference position and the 3D velocity in the local coordinate system (East, North, Up) are provided in the header of each file.

 Position discontinuities

The GT2_discontinuities_Table.txt file provides the position offsets that have been estimated by the GFZ group.


Deng Z., Gendt G., Schöne T. (2015) Status of the IGS-TIGA Tide Gauge Data Reprocessing at GFZ. In: Rizos C., Willis P. (eds) IAG 150 Years. International Association of Geodesy Symposia, vol 143. Springer, Cham