Improving the S/X Celestial Reference Frame in the South: A Status Update

Abstract

Catalogs of positions of compact extragalactic radio sources, including the ICRF-3, are generally weaker in the south by factors of 2 or more in both density and precision. In 2018 we started a campaign to improve the S/X celestial reference frame in the South by upgrading existing IVS astrometric observing programmes. Our efforts were mainly focused on the Celestial Reference Frame (CRF) and Celestial Reference Frame Deep South (CRDS) sessions, which are dedicated astrometric observing programmes of sources at mid-and southern declinations. In particular, the data rate of the CRF and CRD