RSAA Colloquia / Seminars / Feast-of-Facts: Friday, 14 December 2018, 14:00-14:20; CSO Common Room

Jae Boyd

"Evaluation and Comparison of Gimbal Mounts for Adaptive Optics Tracking and Pushing System"

As part of the development of an Adaptive Optics Tracking and Pushing (AOTP) system, the U200-G ULTIMA┬« Gimbal Optical Mount (’old mount’) and OptoSigma BHAN-50S-N Gimbal Optical Mount (’new mount’) were both tested for drift when resting, ability to adhere to a prescribed circular path, and for independence of the X and Y axes. It was found that there was a delay after any reversal in direction, leading to skipped steps, so this was also tested in attempt to quantify the delay. It was found that the old mount exhibited signs of drift during supposedly stationary periods and a jitter in the undriven axis when the driven axis changed direction, leading to a maximum of a 1.2 arcsecond on sky movement. The new mount did not display the signs of drift, and showed lesser signs of movement in the undriven axis, with a maximal jitter of 0.6 arcseconds on sky movement. Both mounts displayed evidence of skipped or missing steps when changing direction, but the exact number was difficult to quantify as tests did not display the same trends. The number of skipped steps varied between 49 to 105 steps.