Joint Working Group

IHRF Implementation

Working Group 0.1.3: Implementation of the International Height Reference Frame (IHRF)

A Joint Working Group of

Term: 2019 – 2023

Chair: Laura Sánchez (Germany), Lead of the GGOS Focus Area Unified Height System
Vice-chair: Riccardo Barzaghi (Italy), Chair of the International Gravity Field Service

Members: H.A. Abd-Elmotaal (Egypt), J. Ågren (Sweden), H. Denker (Germany), W. Featherstone (Australia), R. Forsberg (Denmark), V.N. Grigoriadis (Greece), T. Gruber (Germany), G. Guimarães (Brazil), J. Huang (Canada), T. Jiang (China), Q. Liu (Germany), J. Mäkinnen (Finland), U. Marti (Switzerland), K. Matsuo (Japan), P. Novák (Czech Republic), I. Oshchepkov (Russia), M. Sideris (Canada), D. Smith (USA), M. Varga (Croatia), G. Vergos (Greece), M. Véronneau (Canada), Y. Wang (USA), M. Willberg (Germany), M. Amos (New Zealand), D. Avalos (Mexico), M. Bilker-Koivula (Finnland), D. Blitzkow (Brazil), S. Claessens (Australia), X. Collilieux (France), M. Filmer (Australia), A.C.O.C. Matos (Brazil), J. McCubbine (Australia), R. Pail (Germany), D. Roman (USA), C. Tocho (Argentina), H. Wziontek (Germany).


During the term 2015 – 2019, important advances were achieved: a global core reference network for the IHRF was defined and, within the Colorado experiment, it was possible to compare different methodologies for the determination of the reference coordinates WP. The results are very promising and these activities will be continued in term 2019 – 2023 by the Joint Working Group (JWG) 0.1.3 Implementation of the International Reference Frame – IHRF.


  • Based on the Colorado experiment outcomes, to elaborate a document with detailed standards and conventions for the realization and maintenance of the IHRS.
  • To compute a first static solution for the IHRF core network, to evaluate the achievable accuracy under the present conditions (data availability, computation methods, etc.) and to identify key actions to improve the determination of the IHRS/IHRF coordinates.
  • With the support of the IAG Commission 2, the IGFS and the ICCT to promote the study of
    • quality assessment in the determination of potential values,
    • determination of potential changes with time ?,
    • realization of the IHRS in marine areas.
  • In agreement with the IGFS and the IAG Commission 2, to design a strategy to install an operational infrastructure within the IGFS to ensure the maintenance and availability of the IHRF in a long-term basis. Aspects to be considered are
    • Updates of the IHRS definition and realization according to future improvements in geodetic theory and observations.
    • Regular updates of the IHRF (e.g. IHRFyyyy) according to new stations, coordinate changes with time, improvements in the estimation of reference coordinates and modelling of the Earth’s gravity field, etc.
    • Support in the realisation and utilisation of the IHRS/IHRF at regional and national level.
    • To guarantee an organizational and operational infrastructure to ensure the sustainability of the IHRF.

Networking within the IAG

A strong joint work is planned with

  • International Gravity Field ServiceIGFS, chair: R, Barzaghi (Italy), vice-chair: G. Vergos (Greece).
  • ICCT JSG: Geoid/quasi-geoid modelling for realization of the geopotential height datum, chairs: J Huang (Canada), YM Wang (USA).
  • IAG SC 2.2: Methodology for geoid and physical height systems, chair: G. Vergos (Greece).
  • IAG Commission 2.2 WG: Error assessment of the 1 cm geoid experiment, chairs: M Willberg (Germany), T Jiang (China).
  • IAG Commission 2 JWG: On the realization of the International Gravity Reference Frame, chairs: H. Wziontek (Germany), S. Bonvalot (France)
  • GGOS-BPS WG: Towards a consistent set of parameters for a new GRS, chair U Martí (Switzerland).


Sánchez L., Barzaghi R.: Activities and plans of the GGOS Focus Area Unified Height System. European Geosciences Union (EGU) General Assembly 2020, 10.5194/egusphere-egu2020-8625, 2020

Barzaghi R., Sánchez L., Vergos G.: Operational infrastructure to ensure the long-term sustainability of the IHRS/IHRF. European Geosciences Union (EGU) General Assembly 2020, Vienna, Austria, 10.5194/egusphere-egu2020-7961, 2020

(last update 09.2020)