GENEVA (Realist English). ITU Secretary-General Doreen Bogdan-Martin said at the handbook launch ceremony: “Preventing harmful radio interference is a matter of public safety and can save lives.
An interference-free spectrum keeps weather forecasts accurate, emergency alerts and warnings timely, and climate data reliable — thereby enabling communities to prepare, respond, and build resilience.”
WMO Secretary-General Celeste Saulo emphasized the special nature of the spectrum as a limited natural resource: “Meteorology depends on specific frequency bands — this is not a matter of choice, but a consequence of the physical properties of the atmosphere itself: they provide observations that cannot be obtained on any other frequencies. These bands must be protected.”
Why Certain Frequencies Are Irreplaceable
The radio frequencies on which Earth observation and meteorological satellites depend are not chosen arbitrarily. Some satellite sensors measure extremely weak natural signals at specific frequencies — these frequencies are determined by the physical resonance properties of oxygen and water vapor molecules in the atmosphere and cannot be reproduced in other bands.
Passive remote sensing sensors measure extremely weak signals in themselves, and scientific information is often extracted from minor variations in these signals. Without protective measures, emissions from television, communication, and other transmitters would completely drown out these observations.
A 2025 report by the US National Academy of Sciences notes that these measurements involve “the quantification of extremely weak signals,” and scientific information is usually extracted from their minor variations. That is why protection concerns not only technology but also data quality and forecast reliability.
The Key Battleground of WRC-27: The 8 GHz Band
At the 2023 World Radiocommunication Conference (WRC-23), the UN Office for Outer Space Affairs (UNOOSA), in close coordination with the ITU, successfully protected the 10 GHz band for synthetic aperture radars from interference from terrestrial 5G/6G mobile communication systems. Germany’s representative in the UN Committee on the Peaceful Uses of Outer Space called this “a tremendous success for the space community.”
However, the WRC-27 agenda is broader and deeper. Agenda item 1.7 concerns the use of the 7.125–8.400 GHz band for International Mobile Telecommunications (IMT) systems, and the 8 GHz band (8025–8400 MHz) is the “workhorse” for downlinks of most Earth observation satellites and is simultaneously used by meteorological satellites to broadcast weather data to global users.
UNOOSA warns: “Loss of this spectrum would jeopardize the UN’s ability to provide timely and accurate data critical for disaster management, biodiversity protection, and support for sustainable agriculture, ultimately affecting people’s lives and sustainable development efforts.”
South Korea, in its statement to the UN Committee on Outer Space, also noted: “If terrestrial mobile communication systems are introduced into these bands, it could create interference, affect the operation of Earth observation satellites, and potentially deal a blow to our ability to monitor and study the Earth from space.”
Other Relevant Agenda Items
The WRC-27 agenda contains several other items concerning the protection of remote sensing spectrum:
Item 1.1: consideration of the 47.2–50.2 GHz and 50.4–51.4 GHz bands for earth stations in motion on aircraft and vessels. WMO’s preliminary position is “no objection,” provided that protection of passive remote sensing in the 50.2–50.4 GHz band continues to be ensured through mandatory unwanted emission limits.
Item 1.2: review of sharing conditions in the 13.75–14 GHz band for the use of smaller-antenna uplink earth stations. The adjacent 13.25–13.75 GHz band is used for various active remote sensing applications, including altimeters, scatterometers, and precipitation radars measuring ocean surface winds, precipitation rates, and sea ice thickness.
Item 1.3: consideration of the 51.4–52.4 GHz band for gateway earth stations of non-geostationary satellites. The oxygen absorption band at 52.6–54.25 GHz is critically important for atmospheric temperature profiles and surface emission characteristics.
Item 1.19: consideration of adding a primary allocation to passive remote sensing in the 4200–4400 MHz and 8400–8500 MHz bands for sea surface temperature measurement.
Seriousness of Interference Consequences
ITU and WMO warn that harmful radio interference can reduce the accuracy and availability of environmental observations, affecting forecasts, emergency alerts, and long-term climate records. Meteorological radars, lightning location systems, aviation and maritime observations, and hydrological monitoring systems all depend on these bands for collecting and exchanging data.
WMO notes in the background document: “Meteorological observations underpin weather forecasting, climate monitoring, and early warning systems. Any degradation in data quality or availability — including from radio interference — can have a direct impact on public safety, economic activity, and environmental protection.”
Spectrum Coordination as Critical Infrastructure
WMO experts at the 2026 European Geosciences Union conference characterized spectrum coordination as “a key element of Earth observation systems,” emphasizing its role in maximizing the economic, social, and environmental value of global meteorological infrastructure, including such socially significant initiatives as “Early Warnings for All” (EW4All).
WMO’s coordination framework includes the WMO Integrated Global Observing System (WIGOS), the WMO Information System (WIS), and the WMO Integrated Processing and Prediction System (WIPPS), which support global numerical weather prediction, climate monitoring, hydrological, and environmental applications.
Outlook
WRC-27 will be held from October 18 to November 12, 2027. The release of the ITU-WMO handbook and the Geneva expert seminar (September 28–30) mark the acceleration of official preparatory work.
Germany, back in 2024 in the UN Committee on Outer Space, clearly urged: “We again encourage member states to study this issue and consider the potential impact of the proposed WRC-27 agenda item 1.7 allocation of the 7.125–8.400 MHz band for mobile communication systems on their Earth observation systems.”
The conclusions of the US National Academy of Sciences report emphasize that as Earth system science advances, the need for more frequent (ultimately nearly continuous) observations will grow, “which argues against applying a ‘time-sharing’ approach to protect remote sensing measurements in bands where Earth observation is shared with other services.”
For weather forecasting and climate monitoring dependent on satellite data, the WRC-27 outcome will determine data quality and availability for years to come. As UNOOSA warns, loss of the 8 GHz band “would jeopardize the UN’s ability to provide timely and accurate data.” The core contradiction of this spectrum battle is between the growing needs of commercial wireless communications and the irreplaceable needs of scientific observations, with the latter concerning the foundations of public safety and climate action.
