Global Geodetic Observing System, Bureau of Networks and Operations
International GNSS Service (IGS) Status Report
Submitted: 24 October 2017
A. Craddock (2) for G. Johnston, Governing Board Chair (1) and R. Neilan, Central Bureau Director (2)
(1) Geoscience Australia, Canberra, Australia
(2) NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
The IGS is a self-governed federation of 388 contributing organizations from 118 countries around the world that collectively operate a global infrastructure of tracking stations, data centers and analysis centers to provide high quality GNSS data products. The IGS products are provided openly for the benefit of all scientific, educational, and commercial users.
Figure 1: The IGS At-a-Glance
Present Status and Progress
IGS Membership has climbed to 340 Associate Members, representing 118 countries; 32 of these members comprise the international Governing Board. The organization is supported by 388 contributing organizations, of which four are product coordinators, and 106 are station operators.
The IGS Network has 506 stations, of which 177 are multi-GNSS and 189 are real-time GNSS. Delivery of core reference frame, orbit, clock and atmospheric products continued strongly, with further refinement of the Real-Time Service and considerable efforts being targeted towards development of standards. The transition to multi-GNSS also continued, with additional Galileo and BeiDou satellite launches bringing those constellations closer to operational status.
Over 500 IGS Network stations are maintained and operated globally by many institutions and station operators, making tracking data available at latencies ranging from daily RINEX files to real-time streams available for free public use (Figure 2). The transition of the IGS network to multi-GNSS capability has been led by the MGEX project team, with much assistance from the Central Bureau and Infrastructure Committee. The transition will has resulted in approximately 50% of IGS network stations being capable of tracking multiple GNSS constellations (GPS + GLONASS + one other) (September 2017). Within the network, 196 IGS stations are now capable of real-time data streaming in support of the IGS Real-Time Service.
Figure 2: The IGS Network as of October 2017, with stations providing RINEX 3.x data indicated in green
Increasing Engagement with Associate Membership
The inaugural Associate Member open meeting was held the morning before the Governing Board meeting in San Francisco, December 2016. Representatives from all IGS working groups gave updates on their workshop recommendations, as a midway progress report between the Sydney 2015 and Paris 2016 workshops. Approximately 45 associate members, observers, and guests participated.
Updates to the Terms of Reference
The IGS Terms of Reference were modified as a matter of general update and review, and may be viewed here: https://kb.igs.org/hc/en-us/articles/115003535547-IGS-Terms-of-Reference-v-02-2017-
Transition from Real Time Pilot Project to Service
The IGS Real Time Pilot Project is now the Real Time Service, with accompanying Working Group.
Adoption of IGS14 Reference Frame
The IGS adopted a new reference frame, called IGS14, on 29 January 2017 (GPS Week 1934). At the same time, an updated set of satellite and ground antenna calibrations, igs14.atx, was implemented. IGS14 is the latest in a series of GNSS reference frames adopted by the IGS. These reference frames form the basis of the IGS products, and are derived from each new version of the International Terrestrial Reference Frame. Updating to IGS14 will align IGS products to ITRF2014, and increase precision of that alignment by integrating additional available reference frame stations with more precise and up-to-date coordinates. For more information, please see [IGSMAIL-7399] “Upcoming switch to IGS14/igs14.atx.”and “IGS14/igs14.atx: a new framework for the IGS products.”
Antenna Calibration Updates
Coincident with the IGS14 Reference Frame release, IGS adopted antenna calibration updates in igs14.atx. These updates include robot calibrations for additional ground antenna types, increasing the percentage of ground stations in the IGS network with absolute calibrations to over 90%. This will result in increased coordinate accuracy for stations equipped with these antennas. SINEX and ANTEX files, as well as network maps, post-seismic deformation models, and offsets are available for download via ftp from Institut National de l’Information Géographique et Forestière (National Institute of Geographic and Forestry Information, IGN) and École Nationale des Sciences Géographiques (National School of Geographic Sciences, ENSG
Joint Monitoring and Assessment Activities with the UN International Committee on GNSS
The IGMA ICG-IGS Joint Trial Project has experienced growth, and idea of using the existing monitoring infrastructure of IGS MGEX was introduced. The Trial Project established a Terms of Reference document, and has distributed Calls for Participation both geared toward ICG providers as well as the IGS community.
The IGS Monitoring and Assessment Working Group was formed as a complement to the ICG-IGS Joint Trial Project.
MGEX Transition from “Experiment” to Pilot Project
The success of the MGEX experiment has demonstrated the inevitability of a transition of the IGS to a full multi–GNSS Service. Accordingly, the Governing Board decided to acknowledge this by terminating the “experiment” status and move MGEX to the status of a Pilot Project. Continued efforts are required to negotiate access to satellite specific information for new satellites from system providers, allowing for more realistic models of satellite behavior to be developed and utilized by the IGS AC’s.
The IGS White Paper on Satellite and Operations Information for Generation of Precise GNSS Orbit and Clock Products is now an official sanctioned IGS paper.
Expansion of Ionospheric Analysis
The Ionosphere WG has increased by three new associate analysis centers contributing to ionospheric combination products, as well as uploading ROTI maps.
New IGS Global Data Center at Wuhan University
Wuhan University has been added as the fifth IGS Global Data Center, and the GB officially endorsed fully-weighted adoption of Wuhan Rapid products. The Wuhan Data Center offers access to the full collection of IGS data and products to any user globally, especially those within the Asia Pacific Region. Importantly the data center gives direct access to the IGS data holdings to the very large research sector within China.
Adoption of RINEX V3.04 and 9-Character Identification Format
The GB agreed to adopt the official RINEX V3.04 format, handling the ability for 9-character id and fixing the definition of GNSS reference time scales. The RINEX Working Group has assumed leadership in maintenance and further development of the RINEX data exchange standard, in cooperation with RTCM-SC104, and has led the recent release of RINEX 3.03. The RINEX Working Group has worked in cooperation with the IC to prepare a plan to transition from RINEX 2.x to RINEX 3.x. The IGS Network map was enhanced to provide information about stations providing data in RINEX 2 and RINEX 3 formats, which may be viewed in real time at: http://www.igs.org/network
Data Center Working Group is working on integrating long filenames, RINEX3 data into operational archives. The Troposphere WG is also incorporating long names in its SINEX.
Completion of IGS Web-Based Asset Transition to IGS.org
The IGS website, product servers, FTP, and mailing lists were updated to reflect the transition from igscb.jpl.nasa.gov to IGS.org. This was the last step in the three-year transition process. More information about this transition may be found here: http://www.igs.org/article/igs-website-server-ftp-and-mailing-list-transitions
IGS 2017 Workshop in Paris, France
The latest IGS Workshop, with the theme of “Pathways to Improved Precision,” took place 3-7 July, 2017. This workshop was hosted locally by the Institut National de l’Information Géographique et Forestière (IGN) and the Centre National d'Études Spatiales (CNES) at the University of Paris-Diderot in Paris, France. Almost 300 individuals from over 30 countries around the world participated in the sessions.
The workshop also featured a special keynote lecture on the Galileo system, given by Marco Falcone of the European Space Agency (ESA). Falcone’s complete presentation, as well as videos of all other plenary presentations, and PDFs of posters, are available on the IGS website: http://www.igs.org/presents.
Ongoing Activities and Planned Actions for 2018
- Preparations are underway for the next IGS Workshop, taking place 29 October to 2 November 2018 in Wuhan, China. The workshop will be hosted by Wuhan University in China, and will be the first IGS Workshop on the Asian continent.
- The Real-time Service will continue to progress toward an operational service including all of the available GNSSs.
- IGS will develop a proposal for an IGS Scientific Applications session at AGU 2018
- IGS Associate and Governing Board members continue to participate in contributing to five focus groups developed to draft the implementation plan for the United Nations Global Geodetic Information Management (GGIM) Global Geodetic Reference Frame Roadmap. Details and updates may be viewed on the UN GGIM website: http://ggim.un.org. This implementation plan will be tabled at the Eighth meeting of the UN GGIM in August 2018 at UN Headquarters in New York.