  A catalog containing milliarcsecond--accurate positions of 1332 extragalactic
radio sources distributed over the northern sky is presented - the Very Long
Baseline Array Calibrator Survey (VCS1). The positions have been derived from
astrometric analysis of dual-frequency 2.3 and 8.4 GHz VLBA snapshot
observations; in a majority of cases, images of the sources are also available.
These radio sources are suitable for use in geodetic and astrometric
experiments, and as phase-reference calibrators in high-sensitivity
astronomical imaging. The VCS1 is the largest high-resolution radio survey ever
undertaken, and triples the number of sources available to the radio astronomy
community for VLBI applications. In addition to the astrometric role, this
survey can be used in active galactic nuclei, Galactic, gravitational lens and
cosmological studies. The VCS1 catalog will soon be available at
www.nrao.edu/vlba/VCS1 .
