7.17. A possibility of measurement of distance and proper motion of galactic sources by using a differential VLBI method of VERA

National Astronomical Observatory, Japan has a plan to construct a new VLBI system named VERA (VLBI Exploration of Radio Astrometry). The system can measure precise positions of Galactic radio sources (H 2 O masers and SiO masers) referring to adjacent radio sources (QSO etc.) by using a differential VLBI method (Sasao and Morimoto, 1991).