GGOS Days 2024

Each year, the GGOS Executive Committee organises the GGOS Days to update the IAG and GGOS communities on recent achievements and current challenges faced by the various colleagues involved in achieving the goals of the GGOS Strategic Plan.


GGOS Topical Meeting on the Atmosphere

GGOS serves as an integrating framework for all components of the International Association of Geodesy (IAG), providing a clearinghouse for geodetic expertise and fostering interdisciplinary research. A current challenging topic is the modelling of spatio-temporal variations of the atmosphere (troposphere, stratosphere, mesosphere, thermosphere, ionosphere/plasmasphere) and the magnetosphere using geodetic and geophysical observations.


IGS 2024 Workshop and Symposium

The IGS started its operational service on 1 January, 1994. During the course of preparing for this operational phase, the first IGS workshop was held at the premises of the University of Bern from 25 to 26 March, 1993 focusing on the analysis centers. The first decade of operational service was celebrated at an IGS workshop hosted again in Bern Switzerland by the University of Bern in March 2004.


GGOS Strategic Plan 2024 – 2034: Geodesy for Science and Society

GGOS, the Global Geodetic Observing System of the International Association of Geodesy (IAG), was established as an integrating framework for all IAG Components (Services, Commissions, Inter-Commission Committees and Projects) to move from the provision of individual geodetic technique-based products to a level of consistent modelling and interpretation of Earth System processes and interactions, ensuring an integrated, consistent and long-term observing system.


From the GGOS Focus Area Unified Hight System to the Coordination Centre for the International Height Reference Frame IHRF

One initial objective of the Global Geodetic Observing System (GGOS) of the International Association of Geodesy (IAG) was the standardisation of height systems worldwide. In this way, the GGOS Focus Area Unified Height System (GGOS-FA-UHS) was established in 2010 to lead and coordinate the efforts needed towards the establishment of a global standard for the precise determination of physical heights.


GGOS Call for Nominations

GGOS is seeking nominations for the position of Director of the GGOS Bureau of Networks and Observations (GGOS-BNO).


Gravity, Geoid and Height Systems 2024

The GGHS2024 “Gravity, Geoid and Height Systems 2024” Symposium will be held in Thessaloniki, Greece, from 4 to 6 September 2024. It focuses on methods for observing, estimating and interpreting the Earth’s gravity field and the essential role of gravity field modelling in measuring, understanding and predicting changes in the Earth system.


20th International Symposium on Geodynamics and Earth Tides

We are pleased to announce that the 20th International Symposium on Geodynamics and Earth Tides (G-ETS) will take place in Strasbourg (France) from August 25 to August 30, 2024. The G-ETS 2024 will be held under the umbrella of the IAG (International Association of Geodesy) and, in particular, through the IAG Sub-Commission 3.1 (Earth Tides and Geodynamics) and International Geodynamics and Earth Tide Service.


New Film about Terrestrial Reference Frames

Due to the success and very positive response to the film Discover GGOS and Geodesy we are working on the production of more videos about geodetic products. Now we are proud to present the new film Terrestrial Reference Frames – Connecting the World through Geodesy, which shows the great importance of ITRF for science and society.


Proceedings of the IAG Symposia at IUGG Berlin

Submissions are welcomed for the Berlin IUGG volume of the IAG Symposia series, with an initial submission deadline of October 15. Papers are welcome from any of the IAG symposia, or from joint symposia sponsored or co-sponsored by IAG. All papers will be published Open Access, and the cost for this is covered by the IAG.


IUGG General Assembly 2023 Summary

The 28th IUGG General Assembly was held on 11-20 July 2023 in Berlin, Germany. It gathered a total of 5000 participants which is a record of IUGG General Assemblies. The number of IAG participants was about 580 which is also a record in the General Assemblies.


Next GGOS President

Laura Sanchez from DGFI/TUM was elected by the IAG Executive Committee during the 28th General Assembly of the IUGG as a new GGOS President. She will take over the presidency from Basara Miyahara and serve in this function from July 20, 2023.


IAG Opening Ceremony - Awards and Prizes

IAG held its opening ceremony at the 28th IUGG General Assembly and announced the winners of the Levallois Medal, the Guy Bomford Prize, the Young Authors' Award and the Best Reviewer Award. Now with Laudations!


IAG welcomes the participants of the IUGG 2023 General Assembly, Berlin, Germany

The scientific program of IAG starts on Wednesday morning (July 12) and lasts until the evening of the next Wednesday on July 20, 2023! Eight days of interesting talks, lively poster sessions and fruitful discussions helping to further advance geodetic research and services provided to the geoscientific community.



The 20th WEGENER Assembly 2023 (WEGENER-20) will be organized by the National Office of Mines (ONM, Geological Survey of Tunisia) from 24 to 27 October 2023 in Sousse, Tunisia. The abstract and registration deadlines have been updated!


GGOS Portal Survey

GGOS values your opinion! Take a look at the GGOS Portal Survey!


Workshop in SAR for Geodesy

You are warmly welcome to the Workshop in SAR for Geodesy organized at Otaniemi, Espoo, Finland and in Zoom 13. –14.3.2023


GGOS Strategic Plan Survey

As GGOS reaches its 20th anniversary of service to the IAG and global geodesy community, we need your input to inform and guide the goals of the next GGOS Strategic Plan.


Call for Papers

IAG International Symposium on Reference Frames for Applications in Geosciences (REFAG 2022), Thessaloniki, Greece, October 17-20, 2022
Abstract Deadline: July 20, 2022!


REFAG 2022 - Call for papers

IAG International Symposium on Reference Frames for Applications in Geosciences (REFAG 2022), Thessaloniki, Greece, October 17-20, 2022


IAG Statement on Ukraine

The International Association of Geodesy and its services strongly condemn the unprovoked and premeditated Russian invasion of Ukraine. We are deeply troubled by the loss of life and hundreds of thousands of civilians becoming refugees, and are very concerned about the safety and well-being of our scientific colleagues in Ukraine. We strongly request that the responsible people stop the military actions immediately.


Discover GGOS

Do you know what geodesy is exactly and what GGOS does? This film immerses you in the world of geodesy and outlines its benefits for society.


Tour de l'IGS

The Tour de l’IGS is a series of virtual workshops on relevant topics to the IGS membership, stakeholders and GNSS community in general. These events will be hosted several times a year and will cover a wide range of topics including space-borne and ground-based instrumentation, technology development, scientific and societal applications, etc.


X. Hotine-Marussi Symposium

The jubillee X Hotine-Marussi Symposium will be organized at the Politechnico di Milano, Italy on June 12-17, 2022. See the first crcular for more details!


ILRS Virtual World Tour 2021

Due to the COVID 19, we have had to postpone our laser workshops, our annual seminal events, in 2020 and 2021. The ILRS again wishes to provide the opportunity for our worldwide community to meet, at least virtually, and share. Following the success of the Virtual World Tour last year, we will hold another Virtual World Tour between October 25-29, 2021, to virtually visit 5 stations in 5 days, stopping at Herstmonceux (UK), Wetzell (DE), Mendeleevo (RU), Shanghai (PRC), Monument Peak (USA).


IAG SA manuscript submission to the IAG Symposia Series

The portal for submitting papers for the IAG2021 volume of the IAG Symposia Series is now open. Paper submission will be open until September 30, but we will start the peer review of papers as soon as they are submitted. All papers that are accepted will be available online after acceptance.


The Progress of International Geodesy after World War II

To celebrate the 90th anniversary of the former IAG president Prof. Wolfgang Torge, and the 80th anniversary of Prof. Günter Seeber, a dedicated colloquium is organised at the Leibniz University Hannover on June 8, 2021, 4 pm CEST.


IAG workshop on 'Quantum gravimetry in space and on ground'

We invite you to attend the IAG workshop on « Quantum gravimetry in space and on ground » 26th and 27th of May 2021 2:00-5:00 PM CEST.
This meeting covers quantum gravity sensing, from the development of the sensors and their characterization, to a large panel of present and future applications.


IAG SA 2021 - Abstract Deadline: May 7, 2021!

The IAG Scientific Assembly will be held in Beijing on June 28–July 2, 2021. The Scientific Assembly is a quadrennial event, in the middle of the periods of the IAG General Assembly. Due to the ongoing COVID-19 pandemic, the Assembly will be organized as a hybrid meeting.


New GGOS website launched

IAG's Global Geodetic Observing System works together with the IAG Components – technical services, commissions, inter-commission-committees and IAG-projects – for monitoring the Earth system and global change research. GGOS has launched its new website at, where you can read how geodesy and geodetic observations can contribute to the deeper understanding of our living planet, the Earth!


Join IAG!

The new Membership application page is now opened! This is good time to renew your IAG membership or join IAG for the first time!


International Autumn School on Satellite Gravimetry for Climate Change

The International Autumn School "NEROGRAV" took place 5-9 October 2020 in Bad Neuenahr (near Bonn), Germany. The school was organized by the Research Unit NEROGRAV (New Refined Observations of Climate Change from Spaceborne Gravity Missions) which is funded by the German Research Foundation (DFG).


Ivan I. Mueller celebrates his 90th birthday!

On behalf of the International Association of Geodesy (IAG), namely of President Zuheir Altamimi, of the IAG Executive Committee, and of the entire IAG community, we wish to present to Ivan Mueller cordial wishes for his ninetieth birthday on January 9, 2020, and for the years to come. The undersigned know Ivan Mueller from Post-Doc years and subsequent visits at Ohio State University (OSU), from visits of Ivan Mueller at the Technical University of Munich, and from the creation of the International GNSS (Global Navigation Satellite Systems) Service (IGS).


A welcome message from the IAG President

It is my pleasure to welcome you all, dear visitors of the IAG website, or readers of the IAG Newsletter. It is a great honor for me to serve as IAG President for the period 2019-2023, and to work with the members of the Executive Committee to advance geodesy and our association.


Satellite Laser Ranging School

Prior to the 2019 ILRS Workshop, the ILRS scheduled a one-day introductory course to give non-practitioners in SLR an opportunity to broaden their knowledge about laser ranging to Earth-orbiting satellites and the Moon. The course also provided attendees with some experience in the field an opportunity to refresh and strengthen their knowledge and increase their appreciation of this powerful measurement technique that supports geoscience and applications.


Report on the ILRS Technical Workshop 2019

This year’s International Laser Ranging Service (ILRS) Technical Workshop was hosted by German Aerospace Center (DLR) in Stuttgart, Germany, from October 21st to 25th. Following the motto “Laser ranging: To improve economy, performance, and adoption for new applications” the presentations were focused on the technical challenges for the satellite laser ranging (SLR) ground segment.


IAG ICC on “Geodesy for Climate Research”

During the IUGG General Assembly in Montreal the IAG Executive Committee (EC) established a new IAG Inter-Commission Committee on "Geodesy for Climate Research" (ICCC) to enhance the use of geodetic observations for climate studies. The goal is to establish a systematic and comprehensive approach among the various geodetic communities, but also to establish and foster links to climate science.


To benefit society and science

The new geodetic Earth observatory built by the Norwegian Mapping Authority (NMA) in Ny-Ålesund, 79 degrees north, was successfully inaugurated 6 June.


UN Subcommittee on Geodesy established

Last August the United Nations Committee of Experts on Global Geospatial Information Management (UN-GGIM) decided to elevate the Global Geodetic Reference Frame (GGRF) Working Group to a permanent Subcommittee on Geodesy.


NASA, Norway to Develop Arctic Laser-Ranging Station

NASA and the Norwegian Mapping Authority are partnering to develop a state-of-the-art satellite laser ranging station 650 miles from the North Pole that will produce high-precision locations of orbiting satellites, help track changes in the ice sheets and improve the efficiency of marine transportation and agriculture.


Inauguration of the Onsala Twin Telescopes

The Onsala Space Observatory, Chalmers University of Technology, and the International VLBI Service for Geodesy and Astrometry (IVS) are proud to announce the ceremonial inauguration of a new pair of Twin Telescopes for geodetic and astrometric VLBI. More than 200 international and national guests, including veterans of the first transatlantic VLBI observations in 1968 as well as the regional governors and representatives of Chalmers, participated in the festivity on Thursday, 18 May 2017.


Description of the Global Geodetic Reference Frame

The United Nations General Assembly adopted the resolution on a Global Geodetic Reference Frame for Sustainable Development (A/RES/69/266) on February 26, 2015. The purpose of this document is a description of the Global Geodetic Reference Frame (GGRF), along with a brief description of its key components, as a realization of the Global Geodetic Reference System (GGRS).


Milestone for global geodesy

The UN calls for enhanced cooperation on global geodesy. At the UN-GGIM sixth session in New York in August, the UN Committee of Experts on Global Geospatial Information Management endorsed the GGRF Roadmap and decided to establish a permanent Sub-Committee on Geodesy.


IAG Events