SDSS-IV MaNGA IFS Galaxy Survey --- Survey Design, Execution, and
  Initial Data Quality
  The MaNGA Survey (Mapping Nearby Galaxies at Apache Point Observatory) is one
of three core programs in the Sloan Digital Sky Survey IV. It is obtaining
integral field spectroscopy (IFS) for 10K nearby galaxies at a spectral
resolution of R~2000 from 3,622-10,354A. The design of the survey is driven by
a set of science requirements on the precision of estimates of the following
properties: star formation rate surface density, gas metallicity, stellar
population age, metallicity, and abundance ratio, and their gradients; stellar
and gas kinematics; and enclosed gravitational mass as a function of radius. We
describe how these science requirements set the depth of the observations and
dictate sample selection. The majority of targeted galaxies are selected to
ensure uniform spatial coverage in units of effective radius (Re) while
maximizing spatial resolution. About 2/3 of the sample is covered out to 1.5Re
(Primary sample), and 1/3 of the sample is covered to 2.5Re (Secondary sample).
We describe the survey execution with details that would be useful in the
design of similar future surveys. We also present statistics on the achieved
data quality, specifically, the point spread function, sampling uniformity,
spectral resolution, sky subtraction, and flux calibration. For our Primary
sample, the median r-band signal-to-noise ratio is ~73 per 1.4A pixel for
spectra stacked between 1-1.5 Re. Measurements of various galaxy properties
from the first year data show that we are meeting or exceeding the defined
requirements for the majority of our science goals.
