All posts by Juha Kallunki

CRAF to initiate studies on the aggregate interference from multiple satellite systems at CEPT-ECC

With the expected enormous increase in the number of satellite systems planned to operate during the next decade, CRAF proposed to initiate studies at CEPT-ECC to define a methodology to assess the aggregate effect of satellite systems into existing RAS bands/stations in Europe. Currently, the studies for RAS protection are carried out based on the data loss criteria defined by ITU-R regulations not to exceed the 2% level per individual system. The ITU-R regulations also defines a total data loss limit of 5% from aggregated interference that the RAS has to accept from multiple systems. However, no clear procedures have been established till now on how to implement this aggregate limit practically due to its complexity. Several aspects will need to be taken into consideration, among these are the individual contribution of each satellite system to the overall data loss in certain RAS bands and whether satellite systems could share the burden of reducing the total data loss in case of exceeding the 5% threshold.

The proposal concept was initially approved by ECC project team SE40 of space services and a new work item is expected to be formally approved during the next ECC plenary.

CRAF Participated in the ITU Working Party 7D meeting – April 2021

CRAF, representing the European Radio Astronomy observatories, participated in the Working Party 7D meeting organized by the ITU Radiocommunication Sector and held virtually from 12 to 16 April. WP7D covers the radio astronomy service studies at ITU. Its scope includes radio astronomy and radar astronomy sensors, both Earth-based and space-based, including space very long baseline interferometry (VLBI).

The meeting discussed the progress made on the various agenda items of the next World Radiocommunication Conference 2023 (WRC23) related to the radio astronomy service. CRAF contributions focused on the agenda items of mobile services, UHF review in region 1, and the protection of receive-only space weather sensors. CRAF also continued coordination during the meeting on the new questions for the recognition of the VLBI global Observing System (VGOS) services by ITU.

CRAF is considering an upgrade for the radio astronomy UHF band 608 – 614 MHz to a primary status in ITU-R Region 1

The UHF band 608–614 MHz has been always of considerable importance to radio astronomy as it bridges the large gap between the 410 MHz and 1 400 MHz Radio Astronomy Service (RAS) spectrum allocations. The band is currently used under a secondary allocation in the European part of ITU-R region 1. Whereas in the African Broadcasting Area of Region 1 (roughly most of Africa and parts of the Middle East), the band 606-614 MHz is used under a primary allocationfor RAS according to footnote 5.304.

CRAF participated in the second online meeting of Project Team D (PTD) of the WRC-23 CEPT Conference Preparatory Group (CPG) during the second week of February 2021. Project Team D is addressing WRC-23 agenda item 1.5, where the UHF band in region 1 is under review. In its input contribution to the meeting, CRAF proposed a harmonized position for CEPT for an upgrade to the RAS band 608 – 614 MHz to a primary status in region 1. Nevertheless, the meeting decided to defer considering the upgrade until more compatibility studies for RAS and other services operating in the UHF band become available. CRAF plans to continue the discussions on the agenda item during the upcoming ITU-R working party 7D web-meeting planned on the period from 12th – 16th April 2021.