The early years of radio astronomy in France

Abstract

ORIGIN It was Yves Rocard, appointed Director of the Physics Laboratory of the “Ecole Normale Superieure” at the end of the Second World War, who introduced radio astronomy in France. A member of the Free French Forces, Rocard had very closely followed the technical developments that the allied war efforts stimulated, and he knew the importance of the first observations by British radars. In 1946, Rocard formed a group of physicists around 3.F. Denisse and J.L. Steinberg, including 3. Arsac, E.3. Blum, A. Boischot, E. Le Roux, P. Simon, among others. This group initially had at its disposal two Wurzburg radar antennas retrieved in Germany: a 7.5 m reflector with full steerability and usable for decimetric waves, which was installed about 20 km from Paris, and a second 3 m reflector mounted on the roof of the Paris laboratory. By 1953 it became evident that there was a need for systems of antennas with large dimensions and also for protecting these from the radio interference of the urban environment. This led to creation of a specialized observatory in Nancay, about 200 km south of Paris, where the first important instruments were installed. In 1954, on the initiative of A. Danjon, Director of the Paris Observatory, the team moved to its new laboratories at the Meudon Observatory. At that time, I had just been appointed to the observatory, after several years in the USA and Canada, working with such scientists as G. Reber, F. Haddock, and A.E. Covington. I was to lead the group until the beginning of the 1960's, by which time it had grown to about 40 scientists and students, engineers and technicians.