to consider studies on the technical and regulatory provisions necessary to protect radio astronomy operating in specific Radio Quiet Zones, and in frequency bands allocated to the radio astronomy service on a primary basis globally, from aggregate radio-frequency interference caused by non-geostationary-satellite orbit systems, in accordance with Resolution 681 (WRC-23)

Summary & analysis of ITU-R studies

The study is led by ITU-R Working Party 7D. It seeks a way to characterise and bound the aggregate radio-frequency interference that non-GSO constellations cause to radio astronomy, both in the globally primary radio-astronomy bands and in the Radio Quiet Zones of the two named observatories.

Points to watch

• The protection metric must bound the summed interference from a whole constellation, not just one satellite at a time.
• The RQZ studies focus on two named facilities — the SKA Observatory in South Africa and ALMA in Chile — including the possible recognition of their zones and coexistence measures that satellites can actually implement (Res. 681).
• Protection is sought in bands where radio astronomy is primary worldwide, so the measures would have global reach.
• Any limit has to be something constellation operators can meet without an impractical redesign.

Status

Regional and national positions are still being formed in ITU-R and the regional preparatory groups, with studies running to CPM27-2 in 2027. This page reflects official positions as they are published and does not attribute preliminary views to specific administrations.