CRAF Newsletter 2005/1

May 2005

The European Science Foundation is an association of its 76 member research councils and academies in 29 countries. The ESF brings European scientists together to work on topics of common concern, to co-ordinate the use of expensive facilities, and to discover and define new endeavors that will benefit from a co-operative approach
The scientific work sponsored by ESF includes basic research in the natural sciences, the medical and biosciences, the humanities and the social sciences.
The ESF links scholarship and research supported by its members and adds value by cooperation across national frontiers. Through its function as coordinator, and also by holding workshops and conferences and by enabling researchers to visit and study in laboratories throughout Europe, the ESF works for the advancement of European science.

On behalf of European radio astronomers, the ESF Committee on Radio Astronomy Frequencies, CRAF, coordinates activities to keep the frequency bands used by radio astronomers free from interference.

Contents

1. Chairman's corner

First I want to thank the authors of the New Radio Astronomy Frequency Handbook and in particular Jim Cohen for this great achievement. I hope that the Handbook will be read not only by most of our radio astronomy colleagues but also that it will be seriously considered by the active users of the radio spectrum, as a reference text aimed at making clear what Radio Astronomy needs in order to continue its mandate toward new fundamental scientific results for all humankind.

CRAF is now entering into the second year of the RadioNet budget that is helping us to enlarge our outreach capability, especially by financing the Second Summer School in Spectrum Management for Radio Astronomy. As we go to press we have confirmations from 21 international teachers and 22 students. A few of these might bring the rejuvenated energy that will be required to handle our future tasks.

Roberto Ambrosini - Istituto di Radio Astronomia, Bologna

2. Report from the 40th CRAF meeting [11-12 April 2005]

The 40th CRAF meeting was held on 11-12 April 2005 at the Istituto di Radioastronomia I.N.A.F., Bologna on kind invitation of the Istituto di Radioastronomia.

The meeting commemorated Pierre Cugnon who died in 2004 at the age of 64 years. He was CRAF member for Belgium from 1993-2004.

Key items discussed were:

  • The ESF- and RadioNet-sponsored Workshop on “Active Protection of Passive Radio Services” was held on October 28-29, 2004, at Cagliari, Italy. The heart of the workshop was an open discussion on the second day. The meeting agreed on the need for good liaison and better communication between the groups working in spectrum management for the passive services.
  • A Summer School on Spectrum Management for Radio Astronomy co-sponsored by RadioNet and IUCAF will be held from 6-10 June 2005 at Castel St. Pietro, Italy. The programme also includes presentations addressing passive services other than radio astronomy.
  • GLONASS: The IUCAF/GLONASS agreement of 1993 states “The GLONASS administration agrees to investigate the ways of reducing out-of band emissions in the frequency band 1610.6-1613.8 MHz to the levels indicated in Recommendation ITU-R RA.769, and to communicate their proposed solution of this problem at a future meeting.” IUCAF has now been informed that although filters will be fitted to all new satellites, the resulting levels of unwanted emissions will be 22dB above the harmful thresholds for radio astronomy. The Russian Federation said that further reduction of the unwanted emissions will not be possible, because of the consequential costs and fear of degradation of service of the GLONASS system. CRAF noted this development with great concern.
  • Iridium satellite system: CRAF and Iridium under the auspices of OFCOM (UK) are evaluating the report of the results of monitoring observations of the Iridium satellite system by the Leeheim Monitoring station (“Leeheim”). The Leeheim measurements were requested by the CEPT ECC in response to CRAF’s concerns on the frequency developments for the Iridium system.
  • Ultra-Wide Band (UWB) issues: TG3 completed a draft ECC Report on the compatibility between UWB technology and radiocommunication services below 10 GHz. This report has been adopted by CEPT. Further work is underway in TG3 to develop UWB regulations for CEPT countries. Within ITU-R, Task Group 1/8 addresses UWB issues globally.
  • Short Range Radar (SRR) at ~24 GHz: CRAF had expressed concerns on the maximum tolerable e.i.r.p. levels for SRR at 24 GHz to protect radio astronomy stations as developed by WG SE. These levels were included in the CEPT Decision on SRR at 24 GHz. After some further work on this issue, the ECC decided not to change these levels. CEPT WG FM is tasked to develop a table of all European radio astronomy stations including their geographical coordinates and separation distances to be included in the Annex to the Decision on SRR at 24 GHz.
  • Publication of mitigation issues: noting significant misunderstandings of reports on mitigation matters CRAF will develop a publication code for such publications in close consultation with IUCAF (see section 4).
  • The 3rd edition of the CRAF Handbook for Radio Astronomy will be published in June 2005 (see section 7).

    3. In Memoriam Pierre Cugnon

    It is with great sadness that CRAF learned of the sudden death of its member Pierre Cugnon on October 17, due to complications following heart surgery.

    Pierre Cugnon was born on April 17, 1940, in Bertrix, a small city in the Belgian Ardennes. He conducted nearly his whole scientific career in the Solar Physics Department of the Royal Observatory of Belgium (ROB). After studies at the University of Liège, where he obtained his PhD in the field of interstellar polarization, he obtained a position in the Department in 1968. Working first on photometric and chromospheric observations from the Uccle station, he then developed a programme of coronal polarimetry that led him to participate personally in 4 total solar eclipse expeditions from 1980 to 1998. In 1990, Pierre played a key role in promoting the Belgian participation to the SOHO EIT instrument, allowing the ROB solar team to become, over the last decade, the prominent group that it is now in solar space research.

    In 1994, Pierre Cugnon became simultaneously Head of the Department, as well as the Director of the SIDC, hosted by the ROB since 1981. Over the last decade, he spent most of his time and energy leading his team and services with dedication, leaving his personal imprint and vision. For instance, he developed, jointly with K. Denkmayr, the Combined Method still used now to improve the sunspot index forecasts and he introduced a quality control for the SIDC data products. A major step was the addition to the SIDC of the European Regional Warning Centre of the ISES, previously hosted by Paris-Meudon. Since then, this operational center has continuously expanded its services under a new name, “Solar Influences Data analysis Center”. In the framework of those activities, Pierre Cugnon was also an active member of several committees and organizations. He had served CRAF from 1993 until his death. .

    He will be also remembered for his rich culture and his humble, gentle and patient manner of interacting with colleagues and leading his team. Pierre Cugnon leaves a wife and two daughters.

    4. Interference Mitigation Publications

    While working in CEPT project teams on the compatibility between radio transmitter developments and radio astronomy, CRAF was recently confronted with a position expressed by industry that protection of radio astronomy is no longer necessary since radio astronomy is able to mitigate interference. The discussion addressed frequencies below 30 MHz in particular and LOFAR frequencies in general. Industry had made statements such as “The methodologies for calculation of interference and protection distances normally used at higher frequencies and for large single antennas with very high gains lead to false results and are not applicable for lower frequency arrays…”. “This was derived from a number of LOFAR publications”. And also: “First LOFAR tests carried out on June 22nd, 2004 at Nançay, showed a high resolution Jupiter burst (undisturbed by RFI) observed at f = 28.05882 MHz which is outside the RAS bands and allocated to radio amateurs with maximum power levels of 950 watt PEP in CEPT”.

    It is to be noted that this industry position is also supported by some Administrations.

    During a special discussion of this matter at the 40th CRAF meeting, it was noted that this industry opinion apparently resulted from a misinterpretation of the information at the LOFAR and Nançay websites. If the websites are being used in the above way by industry then the content will need to be very carefully worded.

    Considering these difficulties that cause much harm to radio astronomy, CRAF agreed to work on the development of a publication code for interference mitigation publications. It will work on this matter in close cooperation with IUCAF.

    5. New 40-m radiotelescope at Yebes, Spain

    A new 40-m radiotelescope in Yebes was inaugurated on April 26th, 2005, in the presence of Their Royal Highnesses the Princes of Asturias. The Yebes site is protected against radio interference by law since 2003.

    History

    The project of building a new 40-m radiotelescope was conceived in the early 1990's as one of the most important elements of the plan drawn by the Instituto Geográfico Nacional (IGN) for the development of radioastronomy in Spain. During a scientific international workshop of experts held in 1992, the astronomers and engineers of the National Astronomical Observatory (OAN) identified the most interesting fields of scientific research in order to define the technical characteristics of the new radiotelescope. The feasibility study followed in 1994-95, which pointed out that most of the instrument could be built by Spanish industry. The engineering project was finished in 1996-97, and the construction of the radiotelescope started in 1998.

    Radio telescope description

    The radiotelescope has an alt-azimuth mount, with Nasmyth-Cassegrain optical configuration. The main reflector is a 40-m paraboloid, comprising 420 high-precision aluminum panels. The subreflector, an hyperbolic mirror of 3-m diameter, is located on a quadrupod. The receiver cabin is quite large (8x9x4 m), therefore allowing the simultaneous installation of many receivers. The telescope structure follows homology principles and can survive winds of up to 180 km/h. Pointing is better than 4 arcseconds. The instrument is designed to perform observations in the range 2 – 120 GHz. All cryogenic receivers for the different frequency bands are being constructed in the laboratories at Yebes. First light is planned for the end of 2005.

    Scientific objectives

    The new radiotelescope will be able to perform observations as a single-dish or in combination with other large radiotelescopes around the world. By using the Very Long Baseline Interferometry (VLBI) techniques, combining the signals of several distant telescopes, it is possible to obtain maps with the highest angular resolution ever achieved in astronomy. These studies are of fundamental importance to understand some of the most distant objects known in the Universe, like black holes in the centres of radiogalaxies. VLBI also has applications in Geodesy and Geophysics, as it can measure the tectonic plate displacements or the precise position of the Earth's pole. As a single-dish antenna, the new radiotelescope will be a general-purpose instrument in astronomy and will be used for many interesting studies such as the chemical composition of comets, the formation of stars in our Galaxy and the structure of local and distant galaxies.

    6. Frequencies for sale

    The cost of doing radio astronomy in Britain looks set to rise by nearly one million pounds per annum as a result of government policy on spectrum pricing. The Particle Physics and Astronomy Research Council (PPARC) already pays Ofcom one third of a million pounds per annum in spectrum fees. New proposals put forward in an Ofcom Consultation document seek to quadruple this fee by charging full economic costs, "based on the value of the alternative use of the spectrum (i.e. opportunity cost)." In Ofcom's view, "the continued limitation of interference in large and potentially valuable blocks of spectrum for radio astronomy imposes a cost on the economy" by denying the use of some frequencies to other potential users in the vicinity of a radio observatory.

    Ofcom acknowledges that radio astronomers have little choice over the frequencies they use, and that their observations are vulnerable to radio frequency interference. However it is Ofcom's view that "there are steps radio astronomers can take to mitigate the effects of interference, such as ... using overseas facilities to obtain data. The application of pricing and trading will provide incentives to influence these choices in a way that makes the best possible use of the spectrum".

    "Ofcom believes that market mechanisms are generally more effective than centralised control in achieving optimal use of the radio spectrum and that traditional spectrum management methods based on regulation are no longer sustainable in the face of growing demand for spectrum and proliferating technologies." The market driven approach would allow radio astronomers to trade their potentially valuable spectrum with commercial bodies and keep the profits. For example, if a radio observatory did not need a certain frequency band for several months a year "they may wish to make this time available to other services for the duration of the downtime." "Ofcom appreciates that the radio astronomy community will continue to make research its main priority. Nonetheless there could be worthwhile benefits to be gained from faciliting flexibility in the use of radio astronomy bands."

    I am reminded of the famous definition of the cynic, one "who knows the price of everything and the value of nothing" (Oscar Wilde).

    Jim Cohen - Jodrell Bank Observatory, UK

    7. CRAF Handbook for Radio Astronomy - 3rd edition

    The 3rd edition of the CRAF Handbook for Radio Astronomy will be published in June 2005. The Handbook reviews the needs of the Radio Astronomy Service and the measures required for its continued protection.

    The Handbook provides a comprehensive view of matters related to spectrum management and the protection of the science of Radio Astronomy against harmful interference. The review is placed within the historical and technological context within which the Radio Astronomy Service operates.

    This book is intended for a wide readership. It aims to provide a bridge between radio spectrum management and radio astronomy, so that professional spectrum managers can better understand the needs of Radio Astronomy, and radio astromers can better understand the regulatory process.

    It is ten years since the first edition of the Handbook appeared. The third edition includes new discussions on radio astronomy in space, and on passive remote sensing of the Earth's atmosphere, as well as new threats such as ultra-wide band (UWB) technology.

    The Table of contents of the 3rd edition of this Handbook is in summary:

    For more information about the CRAF Handbook for Radio Astronomy, please contact the committee secretary.

    8. Abbreviations used in this Newsletter

    CEPT = Conference of European Post and Telecommunication administrations
    CRAF = Committee on Radio Astronomy Frequencies (ESF)
    ECC = Electronics Communications Committee (CEPT)
    EIT = Extreme ultraviolet Imaging Telescope
    ESA = European Space Agency
    ESF = European Science Foundation
    FM = Frequency Management
    GLONASS = Global Navigational Satellite System (Russia)
    IGN = Instituto Geográfico Nacional (Spain)
    INAF = Istituto Nazionale Astrofisica (Italy)
    ISES = International Space Environment Service
    ITU = International Telecommication Union
    ITU-R = International Telecommunication Union - Radiocommunication Sector
    IUCAF = Scientific Committee on the Allocation of Frequencies for Radio Astronomy and Space Science (UNESCO)
    LOFAR = Low Frequency Array (Netherlands)
    NASA = National Aeronautics and Space Administration (USA)
    OAN = National Astronomical Observator (Spain)
    OFCOM = Office of Communications (UK)
    PEP = Peak Envelope Power (of a radio transmitter)
    PPARC = Particle Physics and Astronomy Research Council (UK)
    RA = Radio Astronomy
    RAS = Radio Astronomy Service
    RFI = Radio Frequency Interference
    ROB = Royal Observatory of Belgium
    SE = Spectrum Engineering (CEPT)
    SIDC = Solar Influences Data analysis Centre (Belgium)
    SOHO = Solar and Heliospheric Observatory (NASA and ESA)
    SRR = Short Range Radar
    TG = Task Group
    UWB = Ultra Wide Band
    VLBI = Very Long Baseline Interferometry
    WG = Working Group

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    Editorial Group: R. Ambrosini, W. van Driel, R.J. Cohen, P. Scott

    Last modified: 27 May, 2005