Understanding Global Galactic Star Formation
  We propose to the community a comprehensive UV/optical/NIR imaging survey of
Galactic star formation regions to probe all aspects of the star formation
process. The primary goal of such a study is to understand the evolution of
circumstellar protoplanetary disks and other detailed aspects of star formation
in a wide variety of different environments. This requires a comprehensive
emission-line survey of nearby star-forming regions in the Milky Way, where a
high spatial resolution telescope+camera will be capable of resolving
circumstellar material and shock structures. In addition to resolving
circumstellar disks themselves, such observations will study shocks in the jets
and outflows from young stars, which are probes of accretion in the youngest
protoplanetary disks still embedded in their surrounding molecular clouds.
These data will allow the measurement of proper motions for a large sample of
stars and jets/shocks in massive star-forming regions for the first time,
opening a new window to study the dynamics of these environments. It will
require better than 30 mas resolution and a stable PSF to conduct precision
astrometry and photometry of stars and nebulae. Such data will allow production
of precise color-color and color magnitude diagrams for millions of young stars
to study their evolutionary states. One can also determine stellar rotation,
multiplicity, and clustering statistics as functions of environment and
location in the Galaxy. For the first time we can systematically map the
detailed excitation structure of HII regions, stellar winds, supernova
remnants, and supershells/superbubbles. This survey will provide the basic data
required to understand star formation as a fundamental astrophysical process
that controls the evolution of the baryonic contents of the Universe.
