The selection of LEGUE disk targets for LAMOST's pilot survey
  We describe the target selection algorithm for the low latitude disk portion
of the LAMOST Pilot Survey, which aims to test systems in preparation for the
LAMOST spectroscopic survey. We use the PPMXL (Roeser et al. 2010) astrometric
catalog, which provides positions, proper motions, B/R/I magnitudes (mostly)
from USNO-B (Monet et al. 2003) and J/H/Ks from The Two Micron All Sky Survey
(2MASS, see Skrutskie et al. 2006) as well. We chose 8 plates along the
Galactic plane, in the region $0^\circ<\alpha<67^\circ$ and
$42^\circ<\delta<59^\circ$, that cover 22 known open clusters with a range of
ages. Adjacent plates may have small overlapping. Each plate covers an area
$2.5^\circ$ in radius,with central star (for Shack-Hartmann guider) brighter
than $\sim8^{\rm th}$ magnitude. For each plate, we create an input catalog in
the magnitude range $11.3<Imag<16.3$ and $Bmag$ available from PPMXL. The stars
are selected to satisfy the requirements of the fiber positioning system and
have a uniform distribution in the $I$ vs. $B-I$ color-magnitude diagram. Our
final input catalog consists of 12,000 objects on each of 8 plates that are
observable during the winter observing season in Xinglong Station of the
National Astronomical Observatory of China.
