GASS: The Parkes Galactic All-Sky Survey. I. Survey Description, Goals,
  and Initial Data Release
  The Parkes Galactic All-Sky Survey (GASS) is a survey of Galactic atomic
hydrogen (HI) emission in the Southern sky covering declinations $\delta \leq
1^{\circ}$ using the Parkes Radio Telescope. The survey covers $2\pi$
steradians with an effective angular resolution of ~16', at a velocity
resolution of 1.0 km/s, and with an rms brightness temperature noise of 57 mK.
GASS is the most sensitive, highest angular resolution survey of Galactic HI
emission ever made in the Southern sky. In this paper we outline the survey
goals, describe the observations and data analysis, and present the first-stage
data release. The data product is a single cube at full resolution, not
corrected for stray radiation. Spectra from the survey and other data products
are publicly available online.
