Being a modern geodetic measuring method, GNSS (Global Navigation Satellite Systems) has reached an important role in geosciences. Within the scope of the Tide Gauge Benchmark Monitoring Working Group (TIGA-WG) of the IGS, GFZ analyses and reprocesses GNSS data of stations near tide gauges (Deng et al, 2014). This allows us to monitor tide gauges for vertical land deformations, e.g. due to postglacial uplift. TIGA also contributes to the calibration of satellite altimeters and the unification of height systems (Hunegnaw et al., 2017). In conjunction with circa 400 global IGS stations, GFZ processes data of almost 500 GNSS stations near tide gauges between 1994 and today (Fig. 1). In the first TIGA combination there are contributions from 3 international ACs. The GFZ TIGA solution shows the best accuracy among the three submitted solutions (Hunegnaw et al., 2017).
Since the GFZ TIGA processing complied with the accords of the 2nd IGS reprocessing campaign, our reprocessed solutions contributed to the determination of the ITRF20014 (Rebischung et al., 2016). In that context the GFZ solution contained the most stations among all of the nine solutions. Because it is the only solution that contains all IGS stations, the IGS Analysis Center Working Group decided at the 2017 IGS Workshop in Paris, to routinely deliver the GFZ TIGA solution to the IGS in order to ensure, that all IGS stations are contained in the combined weekly IGS solutions.
GFZ TIGA products are available via FTP servers of GFZ and CDDIS. The GFZ FTP server provides daily and weekly files for coordinates, orbits and Earth rotation parameters.
ftp://ftp.gfz-potsdam.de/pub/transfer/kg_igs/igstiga/solutions/
In addition to coordinate and orbit products, troposphere parameters are provided, which can be used for climate studies:
ftp://ftp.gfz-potsdam.de/GNSS/products/tiga_repro2_tro/
References
Addisu Hunegnaw, Felix Norman Teferle, Kibrom Ebuy Abraha, Alvaro Santamaría-Gómez, Médéric Gravelle, Guy Wöppelman, Tilo Schöne, Zhiguo Deng, Richard Bingley, Dionne Hansen, Laura Sanchez, Michael Moore: On the Scientific Applications of IGS Products: An Assessment of the Reprocessed TIGA Solutions and Combined Products. IGS Workshop 2017, Paris.
Zhiguo Deng, Tilo Schöne and Gerd Gendt, (2014): Status of the TIGA Tide Gauge Data Reprocessing at GFZ, International Association of Geodesy Symposia, October 2013
Paul Rebischung, Zuheir Altamimi, Jim Ray and Bruno Garayt: The IGS contribution to ITRF2014. J Geod (2016) 90: 611. doi:10.1007/s00190-016-0897-6
