Introduction

It is vital for the space-based observing system to carefully manage the use of electromagnetic spectrum frequency allocations and to protect the frequency bands used for remote-sensing.

Specific objectives of these activities are:

• to prevent any artificial emission in those natural atmospheric radiation bands that are used for passive radiometry, in particular in the microwave region
• to secure the allocation of frequencies needed for active measurements, in particular in the microwave spectrum
• to secure the allocation of frequencies needed for safe spacecraft operations and data download, and prevent any interference among the various satellite systems comprising the space-based observing system

Frequency allocations are part of the International Radio Regulations that are developed and negotiated among national telecommunications authorities and eventually agreed at the World Radio Conference, which is organized on a regular basis by the International Telecommunications Union (ITU). Preparations for the World Radio Conference involve detailed studies and assessments by the various communities involved.

For the meteorological community, these issues are addressed within WMO by the Expert Team on Radio-Frequency Coordination (ET-RFC). Within Europe, more than 20 National Meteorological Services and other relevant organizations have established the EUMETFREQ programme in order to coordinate their frequency protection activities.

Frequency management and protection are particularly important for satellite activities in general, and Space Agencies have established the Space Frequency Coordination Group (SFCG) to coordinate their activities in this respect.

WMO Preliminary Position on the WRC-23 Agenda

The detailed information was presented at the WMO Workshop organized for WMO Members "Introduction of the WMO Preliminary Position on the WRC-23 Agenda" (21 & 23 February 2023). Please see here.