U.S. Naval Observatory Astrometry Department

IVS Special Analysis Center
for Source Structure

Operation

The Analysis Center for Source Structure is supported and operated by the United States Naval Observatory (USNO). The main mission of the Analysis Center is to analyze VLBI data to extract intrinsic source structure information for use in maintaining the International Celestial Reference Frame (ICRF). Source structure information is provided in the form of synthesis images and source models suitable for evaluating sources for astrometric and/or geodetic use and for long-term monitoring of sources. Research into the effects of source structure on astrometric position determination is also carried out with emphasis on improving the long-term stability of the ICRF. The web server for the Analysis Center is provided by the USNO.

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Products

Our primary product is the Radio Reference Frame Image Database which holds information on the radio frequency intrinsic structure of most ICRF sources with declination greater than -30 degrees.

Both the raw data and processed images (with their associated source models) can be obtained from this site.

Staff

Dr. Alan L. Fey, Dr. David A. Boboltz,
Dr. Roopesh Ojha, Dr. Ralph A. Gaume,
& Dr. Kerry A. Kingham

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History

In December 1999, the USNO proposed to become an IVS Analysis Center. The USNO Analysis Center for Source Structure was accepted by the IVS as a Special Associate Analysis Center in January 2000.

Charter

The charter of the Analysis Center is to provide products directly related to the IVS determination of the ``definition and maintenance of the celestial reference frame.'' These include, primarily, radio frequency images of ICRF sources, intrinsic structure models derived from the radio images, and an assessment of the astrometric quality of the ICRF sources base on their intrinsic structure.

Primary Service

The primary service of the analysis center is the Radio Reference Frame Image Database (RRFID), a web accessible database of radio frequency images of most ICRF sources with declination greater than about -30 degrees. Source structure information is provided in the form of synthesis images and source models suitable for evaluating sources for astrometric and/or geodetic use and for long-term monitoring of sources. The RRFID contains Very Long Baseline Array (VLBA) images of over 500 sources at radio frequencies of 2.3 GHz and 8.4 GHz. The RRFID also contains VLBA images of over 250 ICRF sources at radio frequencies of 24 GHz and 43 GHz.

Staff

Name Responsibilities
Alan L. Fey Primary scientific contact, Web and data base design and content, Webmaster, Web server administration, VLBA data analysis (imaging), structure analysis
David A. Boboltz VLBA data analysis (imaging), structure analysis
Roopesh Ojha VLBA data analysis (imaging), structure analysis
Ralph A. Gaume Liaison to the ICRF Product Center of the IERS
Kerry A. Kingham Web and data base design and content, Webmaster, Web server administration, geodetic data analysis (imaging), structure analysis


Last modified: Tue Dec 29 09:26:51 EST 2009
Send comments to afey@usno.navy.mil.