The Global Geodetic Observing System of the International Association of Geodesy
Sanchez, Laura; Riddell, Anna; Rodríguez, José Carlos; Angermann, Detlef; Sehnal, Martin; Lidberg, Martin; Gruber, Thomas; Soja, Benedikt; Schmidt, Michael; Melbourne, Timothy; Gross, Richard; Ferrándiz, José Manuel; Craddock, Allison B.; Miyahara, Basar
- Publisher
- Zenodo
- Language
- en
Abstract
The Global Geodetic Observing System (GGOS) represents the coordinated response of the international geodetic community, under the auspices of the International Association of Geodesy (IAG), to the need for continuous monitoring of the Earth system. As geodesy's contribution to the Global Earth Observation System of Systems (GEOSS), GGOS provides the essential reference frames for all position-dependent observations that form the basis for most Earth observations. It measures changes in the Earth's shape, size, gravity field and rotation over time and space. Based on the scientific services of the IAG (IGS, IVS, ILRS, IDS, IERS, IGFS, ISG, PSMSL, IGETS, IDEMS, ICGEM, BGI), GGOS provides operational Earth observation using space- and ground-based geodetic techniques. A key objective is to create an integrated framework that moves beyond technique-specific products to combined, comprehensive datasets and products that allow consistent modelling and interpretation of Earth system processes. This integration is essential for a coherent monitoring system that improves our understanding of global change and its environmental and societal impacts. Achieving this requires strong international and multidisciplinary collaboration, focusing on (1) Aligning geodetic observation techniques, services and analysis methods to ensure consistency of data standards, conventions, models and parameters; (2) Integrating geometric, gravimetric and Earth rotation observations to jointly estimate and model key Earth system parameters; (3) Identify scientific and societal needs that can be addressed by geodetic products, while defining accuracy, time resolution and consistency requirements; (4) Identify and address service gaps with strategic solutions; (5) Increase the visibility of geodesy by improving the accessibility of geodetic observations, information and products to a wide range of users. This contribution highlights recent achievements, ongoing initiatives and key challenges for the future.
Full text
Deutsches Geodätisches Forschungsinstitut TUM School of Engineering and Design Technische Universität München L. Sánchez(1), A. Riddell(2), J. Rodríguez(3), D. Angermann(1), M. Sehnal(4), M. Lidberg(5), T. Gruber(6), B. Soja(7), M. Schmidt(1), T. Melbourne(8), R. Gross(9), J.M. Ferrandíz(10), A. Craddock(9), B. Miyahara(11), G. Vergos(12), C. Tocho(13) (1) Technical University of Munich, Deutsches Geodätisches Forschungsinstitut (DGFI-TUM), Germany, (2) Geoscience Australia, Australia, (3) Yebes Observatory, Instituto Geográfico Nacional, Spain, (4) BEV Federal Office of Metrology and Surveying, Austria, (5) Lantmäteriet, Sweden, (6) Technical University of Munich, Institute of Astronomical and Physical Geodesy, Germany, (7) ETH Zürich, Switzerland, (8) Central Washington University, USA, (9) Jet Propulsion Laboratory, California Institute of Technology, USA, (10) Universidad de Alicante, Spain, (11) Geospatial Information Authority of Japan, Japan, (12) Aristotle University of Thessaloniki: Thessaloniki, (13) Universidad Nacional de La Plata, La Plata, Argentina The Global Geodetic Observing System (GGOS), established by the International Association of Geodesy (IAG),is a global effort to monitor the Earth system. GGOS provides the essential foundation for the accurate measurement, modelling and interpretation of Earth processes, supporting research on global change, Earth deformation and mass exchange within the Earth system. GGOS relies on the expertise of the IAG and its components: Commissions, Committees, InterCommission Committees and Projects drive scientific progress and provide research infrastructure, while the IAG Services coordinate global observation, drive data analysis, and deliver high-accuracy geodetic products. A - What is GGOS? D - GGOS building blocks GGOS: The Global Observing System of the International Association of Geodesy IAG2025 Scientific Assembly | 1 –5 September 2025 | Rimini, Italy To meet the GGOS goals, the observing infrastructure and expertise in geodesy as well as multidisciplinary research must be in place. Following challenges are in focus: •Infrastructure gaps, ageing instruments, global data disparities. •Limited funding for satellite missions and ground stations. •Geodetic reference products on a best-effort basis (long-term operational activities not ensured). •Challenging transition from research to operational services. •Decreasing human resources and limited new talent (fewer university students in geodesy). •Lack of awareness in the policy arena, international high-level initiatives, other Earth sciences and industry. •Difficulty in translating technical geodetic information into actionable insights for decision-makers and the public. B –Driving challenges for GGOS Continue advancing geodesy by: •Providing a comprehensive, unified global geodetic frame of reference for geometry, gravity field, and rotation. •Ensuring an integrated geodetic monitoring/ observation system, rather than a multitude of technique-dependent products. Opportunities •A central interface between science and society. •A transformative role for geodesy. •Geodetic data and products serve science and society far beyond the usual applications of mapping, positioning, navigation and timing. •Geodesy is critical for monitoring the Earth system and tracking global change with unprecedented precision. The IAG established GGOS to expand geodesy beyond mapping the Earth’s surface, aiming to serve both science and society. The main goal is to develop an integrated framework that merges different geodetic data into consistent, comprehensive products, enabling reliable modelling and interpretation of Earth system processes and interactions. GGOS builds as much as possible on existing geodetic networks, data systems and research, incorporating improvements from IAG components. GGOS also includes dedicated organisational structures that unify various geodetic areas and support the achievement of the GGOS goals. C - GGOS organisational elements ECurrent challenges F - Strategic actions in progress Supporting the UN Global Geodetic Centre of Excellence (UN-GGCE) in the implementation of the UN Resolution 69/266 “A Global Geodetic Reference Frame for Sustainable Development” by identifying tangible geodetic contributions to UN Sustainable Development Goals Defining Essential Geodetic Variables (EGVs) to leverage the use of geodesy in broader international and multidisciplinary Earth observation initiatives. Opportunities •Geodesy in the policy arena. •Geodesy infrastructure critical for sustainable development. •Strengthen the geodetic community, infrastructure, and its visibility in policy making. •A call for sustained investment in geodesy. Opportunities •Geodesy shares a common language with other Global Observing Systems. •Clearer communication of geodesy’s essential role in monitoring the Earth system and supporting socio-economic systems. •Increased visibility of geodesy within the geosciences, government agencies and policymaking bodies. •The requirements for supporting EGVs provide a strategic approach to improving the precision, reliability and timeliness of geodetic data and products. Further reading at https://geodesy.science/ggos/ By measuring the Earth's shape, rotation and gravity field in relation to precise and stable reference frames, GGOS delivers important insights into changes between and within the geosphere, atmosphere, hydrosphere, cryosphere and biosphere.
