[ { "id": "authors:ez5w2-27m46", "collection": "authors", "collection_id": "ez5w2-27m46", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181211-080024412", "type": "book_section", "title": "Reference Frame Studies at JPL/Caltech", "book_title": "XIXth General Assembly of the IAU", "author": [ { "family_name": "Dickey", "given_name": "J. O.", "clpid": "Dickey-J-O" }, { "family_name": "Esposito", "given_name": "P. B.", "clpid": "Esposito-P-B" }, { "family_name": "Lestrade", "given_name": "J.-F.", "clpid": "Lestrade-J-F" }, { "family_name": "Linfield", "given_name": "R. P.", "clpid": "Linfield-R-P" }, { "family_name": "Melbourne", "given_name": "W. G.", "clpid": "Melbourne-W-G" }, { "family_name": "Newhall", "given_name": "X. X.", "clpid": "Newhall-X-X" }, { "family_name": "Niell", "given_name": "A. E.", "clpid": "Niell-A-E" }, { "family_name": "Preston", "given_name": "R. A.", "clpid": "Preston-R-A" }, { "family_name": "Standish", "given_name": "E. M.", "clpid": "Standish-E-M" }, { "family_name": "Williams", "given_name": "J. G.", "clpid": "Williams-J-G" }, { "family_name": "Muhleman", "given_name": "D. O.", "clpid": "Muhleman-D-O" }, { "family_name": "Berge", "given_name": "G. L.", "clpid": "Berge-G-L" }, { "family_name": "Rudy", "given_name": "D. J.", "clpid": "Rudy-D-J" } ], "contributor": [ { "family_name": "Swings", "given_name": "Jean-Pierre", "clpid": "Swings-J-P" } ], "abstract": "In recent years, a revolution in astronomical position measurements has been taking place with the advent of modern space techniques. These new techniques, which supplement the traditional astrometric measurements, include laser ranging to the moon and artificial satellites, very-long-baseline interferometry (VLBI) of galactic and extra-galactic radio sources and spacecraft, radio tracking of satellites, and radar-ranging and spacecraft tracking during planetary encounters. Impressive accuracies have been achieved and further improvements are forthcoming. Each technique can be expected to establish its own reference frame which is derived from observations of a particular class of objects. The celestial and terrestrial coordinate systems are related through adopted constants and definitions. Contemporary astronomy has led to the development of three principal celestial coordinate systems: the optical frame (FK4/FK5) based on positions of galactic stars; the planetary/lunar ephemeris frame based on the major celestial bodies of the solar system; and the radio frame constructed from observations of extragalactic radio sources (quasars). Each frame is rotated with respect to others; furthermore, the optical frame offset is time variable. It is important that all frames be interconnected and unified. The optical frame is being connected to the radio frame by VLBI observations of radio emitting stars. The radio frame is being tied to the ephemeris frame in several ways \u2013 one is via differential VLBI measurements between quasars and planet-orbiting spacecraft.", "doi": "10.1017/S1539299600006274", "isbn": "9789027722782", "publisher": "D. Reidel", "place_of_publication": "Dordrecht", "publication_date": "1986", "pages": "93-96" }, { "id": "authors:gnwqg-fd822", "collection": "authors", "collection_id": "gnwqg-fd822", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160421-164244322", "type": "book_section", "title": "Aperture Synthesis Maps of CO Emission from M51", "author": [ { "family_name": "Lo", "given_name": "K. Y.", "clpid": "Lo-K-Y" }, { "family_name": "Berge", "given_name": "G.", "clpid": "Berge-G-L" }, { "family_name": "Claussen", "given_name": "M.", "clpid": "Claussen-M-J" }, { "family_name": "Heiligman", "given_name": "G.", "clpid": "Heiligman-G-M" }, { "family_name": "Keene", "given_name": "J.", "clpid": "Keene-Jocelyn" }, { "family_name": "Masson", "given_name": "C.", "clpid": "Masson-C" }, { "family_name": "Phillips", "given_name": "T.", "clpid": "Phillips-T-G" }, { "family_name": "Sargent", "given_name": "A.", "orcid": "0000-0002-4633-5098", "clpid": "Sargent-A-I" }, { "family_name": "Scoville", "given_name": "N.", "orcid": "0000-0002-0438-3323", "clpid": "Scoville-N-Z" }, { "family_name": "Watson", "given_name": "D.", "clpid": "Watson-D" }, { "family_name": "Woody", "given_name": "D.", "clpid": "Woody-D-P" }, { "literal": "International Union of Radio Science" }, { "literal": "Instituto de Radioastronomia Milimetrica" } ], "abstract": "7\"-resolution maps of CO emission from the central 2' of M51 have been made with the Owens Valley millimeter-wave interferometer. Relative warm gas from giant molecular clouds is seen largely confined to arms coincident with the dust lanes, forming coherent structure on the scale of ~3 Kpc. There is a minimum of CO emission within 400 pc of the center. Integrated CO intensity maps are presented. Non-circular motion of the CO gas is evident from the velocity field.", "publisher": "International Union of Radio Science", "publication_date": "1984" }, { "id": "authors:vnsfy-t1r07", "collection": "authors", "collection_id": "vnsfy-t1r07", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160421-082902012", "type": "book_section", "title": "The Caltech Millimeter Wave Interferometer", "author": [ { "family_name": "Masson", "given_name": "C. R.", "clpid": "Masson-C-R" }, { "family_name": "Berge", "given_name": "G. L.", "clpid": "Berge-G-L" }, { "family_name": "Claussen", "given_name": "Mark J.", "clpid": "Claussen-M-J" }, { "family_name": "Heiligman", "given_name": "G. M.", "clpid": "Heiligman-G-M" }, { "family_name": "Leighton", "given_name": "R. B.", "clpid": "Leighton-R-B" }, { "family_name": "Lo", "given_name": "K. Y.", "clpid": "Lo-K-Y" }, { "family_name": "Moffett", "given_name": "A. T.", "clpid": "Moffett-A-T" }, { "family_name": "Phillips", "given_name": "T. G.", "clpid": "Phillips-T-G" }, { "family_name": "Sargent", "given_name": "Anneila I.", "orcid": "0000-0002-4633-5098", "clpid": "Sargent-A-I" }, { "family_name": "Scott", "given_name": "S. L.", "clpid": "Scott-S-L" }, { "family_name": "Woody", "given_name": "David P.", "clpid": "Woody-D-P" }, { "family_name": "Young", "given_name": "A.", "clpid": "Young-A" }, { "literal": "International Union of Radio Science" }, { "literal": "Instituto de Radioastronomia Milimetrica" } ], "abstract": "The Caltech Millimeter-Wave Interferometer has recently begun observations at a wavelength of 2.6 mm. We describe the instrument and some of the first results from it.", "publisher": "International Union of Radio Science", "publication_date": "1984" } ]