IVS Special Analysis Center
for Source Structure

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.

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.

• Radio Reference Frame Image Database