Astrometry of Fundamental Catalogues: The Evolution from Optical to Radio Reference Frames (Astronomy and Astrophysics Library)

Celestial fundamental catalogues are a prerequisite for the determination of absolute positions and motions in space. Presently, positional astrometry is at the watershed between classical fundamental catalogues, based on moving reference stars, and modern catalogues, based on extragalactic reference objects with non-measurable motion. This book addresses the concepts and methods of the respective construction techniques leading to the stellar frame of the FK5 (Fifth Fundamental Catalogue) and to the newly adopted extragalactic radio reference frame, ICRF (International Celestial Reference Frame), with its extension to optical wavelengths by the Hipparcos Catalogue. While principal outlines of meridian circle observations are given, emphasis is put in some detail on the VLBI technique as applied to astrometry, and to the observational techniques used in the Hipparcos mission, including the tie of the originally non-anchored rigid Hipparcos sphere into the ICRF. Front Matter....Pages I-XIV Fundamental Catalogues....Pages 1-36 The Conventional Fundamental Catalogue FK5....Pages 37-68 Contributions of Space Astrometry to Fundamental Catalogues....Pages 69-98 Astrometry with Radio Interferometers....Pages 99-134 Fundamental Catalogues of Extragalactic Radio Sources....Pages 135-164 The International Celestial Reference Frame: ICRF....Pages 165-188 Hipparcos catalogue tie With conventional celestial reference frames....Pages 189-202 Future Prospects....Pages 203-210 Back Matter....Pages 211-231 1. Fundamental Catalogues -- 2. The Conventional Fundamental Catalogue Fk5 -- 3. Contributions Of Space Astrometry To Fundamental Catalogues -- 4. Astrometry With Radio Interferometers -- 5. Fundamental Catalogues Of Extragalactic Radio Sources -- 6. The International Celestial Reference Frame: Icrf -- 7. Hipparcos Catalogue Tie With Conventional Celestial Reference Frames -- 8. Future Prospects. Hans G. Walter, Ojars J. Sovers. Includes Bibliographical References (p. [213]-226) And Index. Prior to the establishment of a fundamental catalogue of positions, it is necessary to define the reference system which postulates the basic principles to be followed in order to arrive at the star coordinates of the fundamental catalogue.