<title>Progress report on a five-axis fast guiding secondary for the University of Hawaii 2.2-meter telescope</title>

Abstract

A telescope aperture of 2.2-m on Mauna Kea that routinely experiences d/r sub 0 = 4 in the near-IR can achieve a factor of 2 gain in angular resolution by tip-tilt correction of atmospheric-induced wavefront errors. To utilize the gains possible from tip-tilt correction, collimation errors and focus errors must also be removed. For its 2.2-m f/31 telescope, the University of Hawaii is in the process of implementing a five-axis fast guiding secondary consisting of a fast steering mirror platform and slow remote detilt, decenter, and despace collimation and focus drives. The near-term goal is to implement closed-loop tip-tilt image motion correction with open-loop collimation and focus control. The long-term goal is to add closed-loop collimation and focus control. This paper documents the progress to date on the fast steering mirror platform and its spider support structure.