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GGOS IberAtlantic (GGOS IA) functions as a regional node of GGOS, focusing on geodetic activities across the Iberian Peninsula and the Atlantic region. GGOS IA fosters collaboration among geodetic institutions while promoting scientific research and technological development tailored to the region’s unique geophysical characteristics.
Gravity, Geoid and Height Systems 2024
Com2, GGOS, 📅 Event UpdateGravity, Geoid and Height Systems 2024
Introduction
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.
GGHS2024 continues the long history of IAG gravity field related symposia, initially hosted by the IAG Commission 2 (Gravity Field):
those organized by the International Gravity Field Service (IGFS):
And more recently the joint IAG Commission 2 and IGFS Symposia:
On this occasion, GGHS2024 is co-organized by the IAG’s Global Geodetic Observing System (GGOS).
More information on the conference sessions, venue, and hosting city along with important dates for abstract submission, registration, trip and visa arrangements can be found in the symposium website at http://www.gghs2024.com.
Subject – Themes
During the last decade, geodesy in general and gravity field modelling in particular, have experienced a notable growth in their recognition and end-product use by many scientific disciplines.
This was mainly due to the advent of the dedicated legacy satellite gravity missions of CHAMP, GRACE and GOCE, which have brought new insights to both the static and time-variable representations of the Earth’s gravity field. GRACE Follow-On has seamlessly integrated with the 15-year GRACE data record and has become indispensable for a wide variety of geophysical process and climate studies. New mission concepts, like NGGM, new accelerometers for satellite gradiometry, cold atom gravimetry, and new and enhanced processing technologies, shall substantially improve this knowledge with further increased spatial and temporal resolution. Moreover, the continuous availability of altimeters on-board satellites and the improvements in the representation of the marine geoid have provided higher accuracies to shorter spatial scales of the marine geoid and gravity field, ocean topography and circulation as well as the structure of the oceanic crust.
At the time came advancements in traditional terrestrial, airborne, UAV and shipborne gravity instrumentation, which offer considerable improvements in gravity networks and the monitoring of gravity variations. Absolute quantum gravimeters have emerged and are gradually replacing free-fall corner cube ones, concepts on quantum sensors are investigated as future payloads for gravity dedicated space missions, while results from gravimeters based on MEMS and airborne sensors on UAVs are emerging.
Another a major breakthrough for the gravity and geoid community has been the definition of the International Height Reference System (IHRS) and the practical realization of the International Height Reference Frame (IHRF). Concepts for geoid and potential determination have been developed and tested aiming at providing a roadmap for the definition and realization of physical heights into a worldwide frame. The latter can lead to the linkage of local vertical datums to a global one, which is fundamental for monitoring sea level variations, as well as engineering and hydrological and cryosphere studies.
The collocated use of the new datasets and models offered by gravity-field related research improves the knowledge of the Earth system, its sub-systems, coupling processes among them, which are important indicators for climate change. They provide the building blocks for innovative investigations of the solid Earth giving new details of crust and mantle and their variation in time.
Contributions on methods for observing, modelling and interpreting the Earth’s gravity field, the determination of the geoid, the establishment of physical height systems, and the essential role of gravity field modelling in measuring, understanding and predicting changes in the Earth system are welcomed for presentation at the GGHS2024 Symposium.
GGHS2024 Sessions
Session 1: Reference systems and frames in Physical Geodesy
Session 2: Novel technologies in terrestrial, airborne and satellite gravity field determination
Session 3: Static and time-variable global gravity field modelling
Session 4: Regional gravity field modelling and geophysical interpretation
Session 5: Gravity for climate, atmosphere, ocean and natural hazard research
Section 6: Data management, dissemination of results and networking of stakeholders
Author: G. Vergos
The Importance of Geodetic Reference Frames
GGOS, 📰 General NewsThe International Terrestrial Reference Frame (ITRF) is the standard reference frame recommended by a number of international scientific organizations, including the International Union of Geodesy and Geophysics (IUGG) and the International Association of Geodesy (IAG) for Earth science, satellite navigation and positioning applications.
The ITRF provides the foundation for determining positions on Earth and in space, as well as for reliably quantifying our planet’s changes due to geodynamic processes and ongoing climate change. The ITRF ensures a uniform basis to tackle current and future challenges, including a wide range of location based applications (navigation, traffic and fleet management, transport logistics, control of industrial and agriculture machinery, autonomous driving, …) that now deeply pervade our daily life. A uniform global and long-term stable reference frame is also required for understanding the dynamics of our planet, for monitoring climate change phenomena and for operating early-warning systems to protect against natural hazards.
Four space geodetic techniques are currently used for the ITRF computation: Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), Global Navigation Satellite Systems (GNSS), and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS). These four observation techniques now provide observations over 25 to 40 years.
Figure: Space geodetic techniques VLBI, SLR, GNSS and DORIS and their observation time span used for the realization of the geodetic reference system (Source: DGFI-TUM)
The analysis of the VLBI, SLR, GNSS and DORIS observations over this long time span is a tremendous international effort, which is done by four scientific services (IVS, ILRS, IGS and IDS) of the IAG. The three ITRS Combination Centers of the IERS, namely the Institute national de l’information géographique et forestière (IGN) in Paris, the Deutsches Geodätisches Forschungsinstitut of the Technical University of Munich (DGFI-TUM), and the Jet Propulsion Laboratory (JPL) of NASA in Pasadena, are responsible for the combination of the data provided by the four technique-specific IAG Services. The most recent realization of the International Terrestrial Reference System (ITRS), the ITRF2020, was published on 15 April 2022 (https://itrf.ign.fr/en/solutions/ITRF2020).
More information:
Author: Detlef Angermann, Laura Sánchez
Editor: Martin Sehnal
GGOS Japan – Awarded with the Tsuboi Prize
GGOS, 📰 General NewsGGOS Japan celebrates its 10th anniversary this year. It was established as GGOS Working Group of Japan in 2013 and has been entitled as a GGOS Affiliate since 2017.
On October 12, 2023, GGOS Japan was awarded with the Tsuboi Prize (group prize) from the Geodetic Society of Japan. In Sendai where the Society’s annual meeting was held, the award certificates were given to eight institutions (Hitotsubashi University, Geospatial Information Authority of Japan, Japan Coast Guard, National Institute of Polar Research, Japan Aerospace Exploration Agency, National Institute of Information and Communications Technology, National Astronomical Observatory of Japan, and University of Tokyo).
Its continuous contributions to both domestic and international geodetic communities are highly evaluated by the society. After the award ceremony, Toshimichi Otsubo and Basara Miyahara jointly gave a commemorative talk starting with Laura Sánchez’s pre-recorded speech as GGOS President.
Congratulations on the achievements of our Japanese colleagues. GGOS is looking forward to working closely with GGOS Japan and our Affiliate members.
Geodesy Lecture (Japanese only)
Author: Toshimichi Otsubo
Editor: Martin Sehnal