In addition to its use as a stand-alone radio telescope, the Westerbork array participates in the European Very Long Baseline Interferometry Network (EVN) of radio telescopes.
During several periods each year, all the major radio telescopes in Europe observe simultaneously the same objects in on the sky.
The observations are recorded separately at each telescope and are subsequently sent to Dwingeloo for processing and analysis. During these weeks astronomers in effect have a radio telescope as large as the whole of Europe, which provides pictures of the radio sky a thousand times sharper that the Westerbork radio telescope can operating stand-alone.
EVN activities are coordinated by and the observations processed at the Joint Institute for VLBI in Europe (see herebelow), a cooperative foundation set up by the EVN and hosted by ASTRON at our facility in Dwingeloo.
Radio telescopes record signals not only from the sky but also from a wide variety of man-made sources. Radio astronomers are as a consequence active in the regulatory process set up by governments to allocate and control the use of the radio spectrum.
ASTRON maintains active links with the national regulatory administration and participates in th regulatory process in Europe by hosting the bureau of the European Science Foundation's Committee on Radio Astronomy Frequencies. CRAF is an international standing committee of the ESF that represents generally the interests of scientific users of the radio spectrum in international regulatory discussions in Europe.