  Ground-layer adaptive optics (GLAO) systems offer the possibility of
improving the "seeing" of large ground-based telescopes and increasing the
efficiency and sensitivity of observations over a wide field-of-view. We
explore the utility and feasibility of deploying a GLAO system at the W. M.
Keck Observatory in order to feed existing and future multi-object
spectrographs and wide-field imagers. We also briefly summarize science cases
spanning exoplanets to high-redshift galaxy evolution that would benefit from a
Keck GLAO system. Initial simulations indicate that a Keck GLAO system would
deliver a 1.5x and 2x improvement in FWHM at optical (500 nm) and infrared (1.5
micron), respectively. The infrared instrument, MOSFIRE, is ideally suited for
a Keck GLAO feed in that it has excellent image quality and is on the
telescope's optical axis. However, it lacks an atmospheric dispersion
compensator, which would limit the minimum usable slit size for long-exposure
science cases. Similarly, while LRIS and DEIMOS may be able to accept a GLAO
feed based on their internal image quality, they lack either an atmospheric
dispersion compensator (DEIMOS) or flexure compensation (LRIS) to utilize
narrower slits matched to the GLAO image quality. However, some science cases
needing shorter exposures may still benefit from Keck GLAO and we will
investigate the possibility of installing an ADC.
