Allison CraddockIAG Participates in the 16th Session of UN-GGIM
The United Nations Committee of Experts on Global Geospatial Information Management (UN-GGIM) held its sixteenth session at United Nations Headquarters in New York from 5–7 August 2026.
UN-GGIM provides an international forum for coordination and cooperation on global geospatial information management. Its work covers a broad range of disciplines, including geodesy, surveying, mapping, remote sensing, land administration and geographic information systems.
The International Association of Geodesy (IAG) participated in the session as an observer. During the discussion of the report of the UN-GGIM Subcommittee on Geodesy, the IAG delivered an intervention highlighting two issues of particular importance to the global geodetic community: the protection of the radio-frequency spectrum used for geodetic Very Long Baseline Interferometry (VLBI) and the development of a sustainable and resilient global geodetic infrastructure.
The IAG intervention stated:
“The International Association of Geodesy (IAG) commends the Subcommittee on Geodesy for the progress of its work during the intersessional period and, in particular, for its efforts to protect the radio frequency spectrum used for geodetic VLBI observations. VLBI is the only geodetic observing technique that can measure UT1, a parameter crucial for high-accuracy positioning and timing. UT1 is measured using a global network of radio telescopes that observe naturally occurring weak radio emissions from cosmic sources. Strong artificial signals at the same radio frequencies interfere with VLBI’s ability to measure UT1. The IAG thanks the Subcommittee on Geodesy and Member States for their efforts to protect the radio frequency spectrum needed for geodetic VLBI and encourages others to join this effort.
The IAG has over 160 years of experience working with geodetic institutions to build the geodetic infrastructure needed to determine a Global Geodetic Reference Frame. The IAG stands committed to working with the Subcommittee on Geodesy and the UN-GGCE to accomplish our common goal of developing a sustainable and resilient global geodesy supply chain and Global Geodetic Reference Frame and encourages the Subcommittee and the UN-GGCE to undertake any and all consultations needed to achieve that goal.”
IAG intervention by IAG President Richard Gross at 16th Session of UN-GGIM, August 2026 (Credit: Allison Craddock)
The intervention underlined the importance of protecting the observations on which accurate positioning, navigation and timing depend, while also emphasizing the need for sustained international cooperation to strengthen the Global Geodetic Reference Frame.
Further information about the sixteenth session of UN-GGIM is available at:
https://www.un.org/globalgeospatial/en/events/annual-sessions/sixteenth
Author: Richard Gross (President of IAG)
