Interaction between celestial and terrestrial reference frames and some   considerations for the next VLBI-based ICRF
  In this paper we outline several problems related to the realization of the international celestial and terrestrial reference frames ICRF and ITRF at the millimeter level of accuracy, with emphasis on ICRF issues. The main topics considered are: analysis of the current status of the ICRF, mutual impact of ICRF and ITRF, and some considerations for future ICRF realizations. 
Zinovy Malkin, Harald Schuh, Chopo Ma, Sebastien Lambert
astro-ph.IM physics.geo-ph