Space-VLBI phase-reference mapping and astrometry

Author(s): Guirado, JC; Ros, E; Jones, DL; et al.

Source: ASTRONOMY & ASTROPHYSICS  Volume: 371   Issue: 2   Pages: 766-770   DOI: 10.1051/0004-6361:20010370   Published: MAY 2001

We present 5 GHz space-VLBI observations of the quasar pair B1342+662/B 1342+663 that demonstrate the feasibility of phase-reference techniques using an antenna in space. The space-based data were taken by the satellite HALCA, of the space-VLBI mission VSOP. From residual (referenced) phases we derive an upper bound of 10 meters to the uncertainty of the spacecraft orbit reconstruction. An analysis of the phase-reference maps of the sources additionally suggests that the above mentioned uncertainty is likely not larger than 3 meters. With errors of this magnitude, HALCA is a useful tool for astrometric studies of close pairs of radio sources.