Increasing sky coverage with the Gemini North ALTAIR/LGS AO system

The Gemini North (GN) AO system, Altair, has been routinely operating in LGS mode since 2007. Due to the initial optical design, the NGS field-of-view (FoV) is limited to a radius ~ 25" which limits the potential science. To improve this, we have tested the AO/LGS operation using a peripheral wavefront sensor (PWFS) whose patrol field is ~ 4'-7' from the target. This expanded NGS FoV permits greater sky coverage but with decreased resolution, FWHM ~ 0.1" - 0.2" making this mode very suitable for non-imaging spectrographic and integral field unit observations. We present the hardware and software upgrades to PWFS and Altair as well as the software necessary for making this observing mode a routine and integral part of GN operations. Characterization and performance of this new operation mode, known as LGS+P1, are presented.