G
Geodesy

Martin Sehnal

Martin works at the Federal Office of Metrology and Surveying (BEV) in Vienna, Austria. He serves as Director of the GGOS (Global Geodetic Observing System) Coordinating Office and Executive Secretary of the IAG (International Association of Geodesy) Secretariat, where he supports the coordination of GGOS components and leads outreach and communication activities. In addition, he is involved in GNSS (Global Navigation Satellite Systems) activities within one of the EUREF (IAG Reference Frame Sub-Commission for Europe) analysis and data centers.

Geodesy Cartoons – A Creative Tool for Outreach and Education

June 12, 2026
The Geodetic Tailor (cropped). Cartoon by Eda Uzunoglu, distributed by geodesy.science/cartoon. CC BY.
The Geodetic Tailor (cropped). Cartoon by Eda Uzunoglu, distributed by geodesy.science/cartoon. CC BY.

Geodesy is fundamental to understanding our dynamic planet. From monitoring sea-level rise and glacier melt to maintaining precise terrestrial reference frames for GNSS and Earth observation, geodesy provides the scientific backbone for many disciplines represented within the EGU and beyond. Despite its importance, geodesy often remains invisible outside the scientific community. Even within geosc ...[Read More]

Geodesy Cartoon Competition – Turn Science into Smiles

September 1, 2025
Geodesy Cartoon Competition – Turn Science into Smiles

Geodesy is the science of measuring the Earth’s shape, gravity field, and rotation. What if we could make it exciting, fun, and easy for everyone to understand? That’s exactly why the International Association of Geodesy (IAG) and its Global Geodetic Observing System (GGOS) launched the Geodesy Cartoons initiative: to bring geodesy closer to the public through visually engaging and humorous illust ...[Read More]

Geodetic reference frames – Why do we need them?

, , and October 30, 2023
Geodetic reference frames – Why do we need them?

  A geodetic reference frame 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 ...[Read More]

Geodetic Data and Products – Idea of a Central Access Point

and April 3, 2023
Geodetic Data and Products – Idea of a Central Access Point

  The services of the International Association of Geodesy (IAG) provide very important and valuable geodetic data, information, and data products that are increasingly relevant for Earth System research, including monitoring of global change phenomena and a wide range of diverse applications such as satellite navigation, surveying, mapping, engineering, geospatial information systems, and so ...[Read More]