Changes and improvements to the Gemini North Aircraft Avoidance Program at the Gemini North Laser Guide Star facility on Mauna Kea

Since March 2005 Gemini North Observatory routinely propagates a 12W solid state sodium laser into the night sky as part of Adaptive Optics imaging on dimmer portions of the celestial sphere. Gemini along with Keck and Subaru telescopes have created aircraft spotting programs to meet the FAA's rules for aircraft avoidance for outdoor laser propagation. This paper reviews the GN laser safety protocol for the outdoor use of lasers and assessment of the risks considered as part of outdoor laser propagation. We will show the results of Gemini's Aircraft Spotter program, and its continuous development over the past 5 years. As part of a continuous improvement activity Gemini in conjunction with the other laser equipped MK Observatories, Keck and Subaru, is currently testing the use of an all sky camera (ASCAM) to monitor the night sky and shutter the laser for air traffic over the Mauna Kea summit, HI. Use of the ASCAM is expected to increase the efficiency and accuracy of the aircraft spotting program. Gemini not only complies with, but strives to exceed the strict FAA rules for aircraft avoidance for outdoor laser propagation. The creation and implementation of the ASCAM is reviewed in this paper.