The Committee on Radio Astronomy Frequencies (CRAF) is a committee of
the European Science Foundation (ESF).
CRAF is the ESF Expert Committee on Radio Astronomy Frequencies. CRAF co-ordinates the efforts on frequency protection for European radio astronomy, passive remote sensing and related sciences. CRAF is sector member of the Radiocommunication Sector of the International Telecommunication Union (ITU), the global organisation dealing with radio frequency management. CRAF has also formal observer status within the Conférence Européenne des Postes et des Télécommunications (CEPT), which represents 47 national Administrations and is responsible for European radio frequency management. This enables CRAF to participate at all levels within the CEPT.
The preparation of, and participation in, the World Radio Conference WRC-03 have largely determined
CRAF's activities in 2003. The WRC-03 agenda contained several items of great importance for radio
astronomy. The Conference took place in June 2003 in Geneva, Switzerland. CRAF's activities concentrated
on the development of CEPT's European Common Proposals for this conference, in close and active cooperation
with the CEPT. Among the WRC-03 items relevant for radio astronomy the following could be noted:
- development of mandatory limits on unwanted emissions from transmitters on spacecraft into nearby
frequency bands used by radio astronomy.
- regulation of High-Altitude Platform Systems (HAPs) applications, in particular their impact on
frequency bands used by radio astronomy between 30 and 50 GHz.
- conditional secondary allocations for feeder links to/from space systems adjacent to the frequency
band 1400-1427 MHz without the possibility of using them until WRC-07 has reviewed the compatibility
studies requested from the ITU-R and taken appropriate action. This frequency band is the most important
for radio astronomy because it contains the 21-cm emission line from neutral hydrogen (HI) and degradation
of radio astronomy observations in this band will have a severe impact on the further development of
astronomy.
The results of the WRC-03 were largely favourable for radio astronomy. Some items could not be completed fully and were placed on the agenda for WRC-07: i.e., the issues of the mandatory limits and of the feeder links at 1.4 GHz (see above).
CRAF also participated actively in various CEPT working groups and project teams on other important
issues, such as
- the impact of telecommunication by high tension cable systems;
- broadcasting issues: in preparation for a Regional ITU conference in 2004/2005
on the revision of the Stockholm-1961 agreement, and the protection of radio astronomy at 0.6 and
1.4 GHz from interference from a broadcasting-satellite system;
- Ultra Wideband Transmission technology and Short Range Radar for automotive applications, which have
significant impact on the fundamentals of radio frequency regulation and management. In particular,
specific regulations for the protection of the vulnerable passive radiocommunication services (like
radio astronomy) are currently under severe pressure by industrial interests.
Having a single European radio astronomy position on these issues is essential. CRAF provides input to the CEPT to ensure that the radio astronomical and related scientific use of frequencies is known and properly protected.
The CRAF members of IUCAF, the Scientific Committee on Frequency Allocations for Radio Astronomy and Space Science of UNESCO, also help to propagate and support the common European CEPT positions on issues related to the fields of science they represent on a worldwide level within the ITU and other global fora.
In June 2003 the CRAF chair, Dr. Wim van Driel, was nominated as IUCAF chair. He will therefore resign as CRAF chair per December 31, 2003 and it is foreseen that he will be succeeded by Dr. Roberto Ambrosini, pending formal approval by CRAF and the ESF.
The CRAF Newsletter, which is made available on the World Wide Web and in hardcopy format, continues to enjoy a wide interest among national frequency administrations, industry and research organisations. A special issue dedicated to WRC-03 issues was distributed widely at this Conference.
CRAF had two plenary meetings in 2002: in Kiruna (Sweden) on 27-28 March and in Kraków (Poland) on 16-17 October.