Radio Frequency Management
The radio spectrum is a finite resource and the ever-increasing pressure for the use of frequency bands by other users of the spectrum, whose applications in general emit electromagnetic radiation, can lead to harmful radio frequency interference (RFI) within the bands used for radio astronomical observations, thereby degrading the quality of research. New technologies for radio communication are constantly emerging and their potential impact on radio astronomy needs to be studied, in order to assure the protection of radio astronomy observations to adequate levels.
It is essential that radio astronomers have continued access to the radio frequency bands necessary for their research, and that their sensitive observations are free from harmful RFI. In order to achieve this goal regulatory measures are required, besides technical ones. Therefore radio astronomers throughout Europe need to participate actively, and coherently, at both local, national, European and global levels in the process of defining, verifying the compliance with, and enforcing the laws and international treaties that control the use of the radio spectrum.
The task of accommodating all competing radio services and systems within the finite usable range of the radio spectrum comes under the generic title of frequency management. In frequency management matters, the European radio astronomy community is represented by CRAF, the Committee on Radio Astronomy Frequencies of the ESF, the European Science Foundation. CRAF does not have a budget of its own. CRAF employs a full-time pan-European spectrum manager since January 1, 1997, whose annual budget (of 120 000 Euros in 2003) is provided by the radio observatories participating in CRAF, or their funding agencies.
The role of CRAF is 'to keep the frequency bands used by radio astronomers free of interference'. CRAF at present has members from 17 countries, including those who will join the EU in the near future, and a number of international organisations. Its official status in the CEPT (Conference of European Posts and Telecommunications Administrations) and the ITU (International Telecommunication Union) allows it to participate in its own right in European and global fora dealing with the regulatory aspects of radio frequency management. The position of European radio astronomy is presented on a global level by those members of CRAF who are also members of IUCAF, the Scientific Committee on the Allocation of Frequencies for Radio Astronomy and Space Science of UNESCO's ICSU, which is the world-wide body representing radio astronomy in frequency management matters.
The activities of the CRAF members on local, national and European levels include:
- local: liaison with the radio observatories they represent
- national: liaison with the national Administrations in charge of frequency management
- European: participation in CEPT fora
CRAF has created an RFI database, in which information on harmful interference events noted within frequency bands used for radio astronomy observations can be registered. In order to reach its full efficiency, input is required from as many European observatories as possible.
CRAF is actively seeking to intensify and formalize its relation with the European Commission, which is at present rather incidental, as the CEPT has been delegated by the EC to handle frequency management issues within 45 European countries (of which the EU countries are a subset). The EC is gradually working to develop its political profile in radio frequency issues, however, and it favours a spectrum policy governed by the interests of the active (i.e. emitting) radiocommunication services and lacks a strategic view on the specific interests and requirements of the passive (i.e. receive-only) services, like radio astronomy. Recently CRAF representatives were invited for a first, informal, meeting with representatives of the European Commission Directorate General Information Society (Radio Spectrum Policy Aspects) for an exchange of views and ideas. It was concluded that the EC representatives and CRAF will have regular contact through various CEPT channels, and CRAF was asked to provide information on the requirements of radio astronomy with respect to new developments and new research projects. On an ad hoc basis, CRAF could be invited to contribute on relevant issues under discussion in the EC Radio Spectrum Committee or Spectrum Policy Group.
The objectives of the pan-European radio frequency management Networking activities are:
- More efficient and intensive contact between the radio astronomers who use Europes radio telescopes, and whose observations may suffer from the effects of radio interference, and their colleagues involved in frequency management, as united in CRAF, is crucial. In order to increase the efficiency of the complex process of coordinating frequency management on a pan-European scale, regular (bi-annual) meetings between experts and 'ordinary' telescope users are required.
- The learning curve for efficient participation in frequency management at an international level is long (several years at least), and the required skills need to be learned 'on the job', as no formal training courses in frequency management exist that are adapted to radio astronomy. A Summer School organised by experts in radio astronomical frequency management for neophyte astronomers and engineers (potentially) involved in this field is an efficient tool in this process.
The Radio Frequency Management Chair is R. Ambrosini (IRA)