Tide Gauge (TIGA) Working Group
Established: 2001
Chair: TBD
Website: TIGA Working Group
Charter: Tide Gauge Working Group Charter
CHARTER
Changes of sea level are of great concern for communities at coasts and may effect the social and economic development in dramatic ways. For decades to centuries the sea level and it’s change has been measured using tide gauges. However, gauges constitute a local datum, affected not only by climate-related but also by local land changes. Space geodetic techniques are the only viable tool to establish the necessary global reference frame for constraining sea level records to a common global and long-term consistent datum. Providing this frame facilitates the distinction between the relative and geocentric sea level changes by accounting for the vertical uplift of the station, and is, therefore, an important contribution to climate change and coastal hazard studies.
The IGS Tide Gauge Benchmark Monitoring – Working Group (TIGA-WG) is providing the service to analyze GNSS data from stations directly at or near tide gauges (TG). TIGA is recognized by the Global Sea Level Observing System (GLOSS) of the International Oceanographic Commission (IOC) of UNESCO to provide positions and vertical rates for tide gauges and is an important contribution of the IGS to the overarching goals of the Global Geodetic Observing System (GGOS), the Global Climate Observing System (GCOS) and the World Climate Research Programme (WCRP).
The primary product of TIGA is sets of coordinates, velocities, and accuracy estimates for monitoring vertical motions of Tide Gauge Benchmarks (TGBM). The product is made public to support and encourage other applications, e.g. sea level studies. The service may further contribute to the densification of the IGS network, the calibration of satellite altimeters, other oceanographic applications, or the establishment of a World Height System.
Goals and Objectives
- Maintain a global virtual continuous GNSS @ TG network
- Select a set of tide gauges equipped with GNSS, with a long and reliable history, useful for both sea level change studies, and e.g. satellite altimeter calibrations. IGS network operation standards should be applied.
- Promote the establishment of more continuous operating GNSS stations, in particular in the southern hemisphere.
- Promote the establishment of local ties (leveling) between GNSS and TGBMs.
- Provide meta information, e.g. on leveling between benchmarks or data access.
- Provide training to tide gauge operators through workshops, encourage station operators to provide necessary metadata. Through GLOSS advice station operators about the operation of continuous GNSS @ TG stations.
- Compute precise coordinates and velocities of GNSS stations at or near tide gauges in-line with the IGS reprocessing campaigns. Provide a combined solution as the TIGA official product.
- Study the impacts of corrections and new models on the GNSS processing of the vertical. Encourage other groups to establish, e.g. nearby absolute gravity sites.
- Provide advice to new applications.
Work plan 2021-2022
- Finalize the reprocessing of the TIGA network as contribution to IGS-repro3
- Provide a combined product based on the most recent reprocessing (repro3), with
- mean rate per GNSS @ TG with reliable error estimate
- time series of the vertical with scaled formal errors
- full SINEX combined product
- Include the latest TAC results (time series) into the SONEL framework
- Work with GLOSS on the improvement of the network situation
- Work with the IGS CB to increase the visibility of TIGA and its products
- Maintain and expand the current inventory of GNSS @ TG stations at www.sonel.org
- Encourage station operators through GLOSS to provide regular leveling between benchmarks
- Provide a technical guidance document to GLOSS and IHO describing techniques for establishing local ties
Download Tide Gauge Working Group Charter
[Revised Nov 2020]
Members
The Working Group is utilizing the existing infrastructure of the IGS as much as possible without disrupting standard activities. The processing of GNSS data is performed by TIGA Analysis Centers (TAC) outside the IGS operational activities, but may be carried out by existing IGS AC’s. The TIGA network is additionally including non-IGS stations (TIGA Observing Stations, TOS) meeting the IGS network requirements which are collocated with the tide gauges. The time lag for providing GNSS data is less stringent compared to standard IGS operations, to allow also remote stations to participate. IGS, other IAG Services or Groups, GLOSS and the PSMSL may propose and advice on the inclusion of additional TOS stations. The TIGA Product will be generated by TIGA Combination Centers (TCC). The network maintenance and interaction with TOS operators is supported by the TIGA Network Coordinator (TNC), closely related to the support of the TIGA Data Centers (TDC).
| Name | Entity | Host Institution | Country/Region |
|---|---|---|---|
| Guy Wöppelmann | TAC, TNC, TDC | University La Rochelle | France |
| Laura Sánchez | TAC | DGFI/TUM Munich | Germany |
| Minghai Jia | GeoScience Australia | Australia | |
| Norman Teferle | TAC/TCC | University of Luxembourg | Luxembourg |
| Allison Craddock | IGS Central Bureau | ex officio | USA |
| Tom Herring
Michael Moore |
IGS AC coordinator(s) | ex officio | USA
Australia |
| Carey Noll | TDC | CDDIS, NASA | USA |
| Tilo Schöne | Chair | GFZ Potsdam | Germany |
| Simon Williams | PSMSL | PSMSL, NOC Liverpool | UK |
| Gary Mitchum | GLOSS GE (current chair). | University of South Florida | USA |
| Mark Merrifield | GLOSS GE (past chair) | UHSLC, Hawaii | USA |
| Matt King | University of Tasmania | Australia | |
| Benjamin Männel | TAC | GFZ Potsdam | Germany |
| Elizabeth Prouteau | TNC | University La Rochelle | France |
| Médéric Gravelle | TAC/TDC | University La Rochelle | France |
| Daniala Thaller | ? | BKG | Germany |
[Revised Dec 2020]
TECHNICAL INFORMATION
Project Data Center at ULR (SONEL)
SONEL aims at providing high-quality continuous measurements of sea- and land levels at the coast from tide gauges (relative sea levels) and from modern geodetic techniques (vertical land motion and absolute sea levels) for studies on long-term sea level trends, but also the calibration of satellite altimeters, for instance.
SONEL serves as the GNSS data assembly centre for the Global Sea Level Observing System (GLOSS), which is developed under the auspices of the IOC/Unesco. It works closely with the PSMSL and the University of Hawaii Sea Level Center (UHSLC) by developing an integrated global observing system, which is linking both the tide gauge and the GNSS databases for a comprehensive service to the scientific community. It also acts as the interface with the scientific community for the French tide gauge data.
Last Updated on 1 Mar 2024 16:22 UTC