On More than Two Decades of Celestial Reference Frame VLBI Observations in the Deep South: IVS-CRDS (1995 - 2021)
Journal article, 2023
The International VLBI Service for Geodesy & Astrometry (IVS) regularly provides high-quality data to produce Earth Orientation Parameters (EOP), and for the maintenance and realization of the International Terrestrial and Celestial Reference Frames, ITRF and ICRF. The first iteration of the celestial reference frame (CRF) at radio wavelengths, the ICRF1, was adopted by the International Astronomical Union (IAU) in 1997 to replace the FK5 optical frame. Soon after, the IVS began official operations and in 2009 there was a significant increase in data sufficient to warrant a second iteration of the CRF, ICRF2. The most recent ICRF3, was adopted by the IAU in 2018. However, due to the geographic distribution of observing stations being concentrated in the Northern hemisphere, CRFs are generally weaker in the South due to there being fewer Southern Hemisphere observations. To increase the Southern Hemisphere observations, and the density, precision of the sources, a series of deep South observing sessions was initiated in 1995. This initiative in 2004 became the IVS Celestial Reference Frame Deep South (IVS-CRDS) observing program. This paper covers the evolution of the CRDS observing program for the period 1995 to 2021, details the data products and results, and concludes with a summary of upcoming improvements to this ongoing project.
IVS
Keywords:
Geodesy
VLBI
Author
S. Weston
Auckland University of Technology
A. De Witt
South African Radio Astronomy Observatory (SARAO)
Hana Krásná
Vienna University of Technology
Karine le Bail
Chalmers, Space, Earth and Environment, Onsala Space Observatory
NASA Goddard Space Flight Center
Sara Hardin
US Naval Observatory
David Gordon
US Naval Observatory
Shu Fengchun
Shanghai Astronomical Observatory
Alan Lee Fey
US Naval Observatory
Chalmers, Space, Earth and Environment, Onsala Space Observatory
Matthias Schartner
Swiss Federal Institute of Technology in Zürich (ETH)
Sayan Basu
South African Radio Astronomy Observatory (SARAO)
O. Titov
Geoscience Australia
Dirk Behrend
NASA Goddard Space Flight Center
Christopher S. Jacobs
California Institute of Technology (Caltech)
Warren Hankey
University of Tasmania
Federico Salguero
Consejo Nacional de Investigaciones Cientificas y Tecnicas
J.E. Reynolds
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Publications Astronomical Society of Australia
1323-3580 (ISSN) 1448-6083 (eISSN)
Vol. 40 e041Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
DOI
10.1017/pasa.2023.33