  Most of the sky has been imaged with NOAO's telescopes from both hemispheres.
While the large majority of these data were obtained for PI-led projects and
almost all of the images are publicly available, only a small fraction have
been released to the community via well-calibrated and easily accessible
catalogs. We are remedying this by creating a catalog of sources from most of
the public data taken on the CTIO-4m+DECam and the KPNO-4m+Mosaic3. This
catalog, called the NOAO Source Catalog (NSC), contains over 2.9 billion unique
objects, 34 billion individual source measurements, covers ~30,000 square
degrees of the sky, has depths of ~23rd magnitude in most broadband filters
with ~1-2% photometric precision, and astrometric accuracy of ~7 mas. In
addition, ~2 billion objects and ~21,000 square degrees of sky have photometry
in three or more bands. The NSC will be useful for exploring stellar streams,
dwarf satellite galaxies, QSOs, high-proper motion stars, variable stars and
other transients. The NSC catalog is publicly available via the NOAO Data Lab
service.
