Project Overview of the Beijing-Arizona Sky Survey
  The Beijing-Arizona Sky Survey (BASS) is a wide-field two-band photometric
survey of the Northern Galactic Cap using the 90Prime imager on the 2.3 m Bok
telescope at Kitt Peak. It is a four-year collaboration between the National
Astronomical Observatory of China and Steward Observatory, the University of
Arizona, serving as one of the three imaging surveys to provide photometric
input catalogs for target selection of the Dark Energy Spectroscopic Instrument
(DESI) project. BASS will take up to 240 dark/grey nights to cover an area of
about 5400 deg$^2$ in the $g$ and $r$ bands. The 5$\sigma$ limiting AB
magnitudes for point sources in the two bands, corrected for the Galactic
extinction, are 24.0 and 23.4 mag, respectively. BASS, together with other DESI
imaging surveys, will provide unique science opportunities that cover a wide
range of topics in both Galactic and extragalactic astronomy.
