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Global Geodetic Observing System

GGOS is the Observing System of the International Association of Geodesy (IAG). Developed by the GGOS planning group, the proposal was accepted by the IAG Executive Committee and and the IAG Council during the XXIII IUGG General Assembly in Sapporo 2003.

The Global Geodetic Observing System works with the IAG components to provide the geodetic infrastructure necessary for monitoring the Earth system and global change research.

GGOS Vision

Advancing our understanding of the dynamic Earth system by quantifying our planet’s changes in space and time.

GGOS Mission

  • To provide the observations needed to monitor, map, and understand changes in the Earth’s shape, rotation, and mass distribution.
  • To provide the global geodetic frame of reference that is the fundamental backbone for measuring and consistently interpreting key global change processes and for many other scientific and societal applications.
  • To benefit science and society by providing the foundation upon which advances in Earth and planetary system science and applications are built.

We live on a dynamic planet in constant motion that requires long-term continuous quantification of its changes in a truly stable frame of reference. GGOS and its related research and services will address the relevant science issues related to geodesy and geodynamics in the 21st century, but also issues relevant to society (global risk management, geo-hazards, natural resources, climate change, severe storm forecasting, sea level estimations and ocean forecasting, space weather, and others). It is an ambitious program of a dimension that goes beyond IAG, requiring a strong cooperation within the geodetic, geodynamic and geophysical communities, and externally, to related endeavours and communities. GGOS will provide this integration at the highest level, in service to the technical community and society as a whole.

GGOS Organisational Structure




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GGOS Terms of Reference (December 10, 2018)


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Bureau of Networks and Observations

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Bureau of Products and Standards

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Focus Area

Unified Height System

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Geohazards Monitoring

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Sea Level Change, Variability, and Forecasting

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Geodetic Space Weather Research

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GGOS Core Sites
GGOS Calendar