Using pseudo-open loop phase maps, reconstructed from deformable mirror commands obtained from the Gemini Planet Imager Adaptive Optics telemetry, estimates are made for the temporal variation of the atmospheric turbulence at Cerro Pachón. The analysis was done by performing Zernike polynomial fits to the instantaneous phase maps to produce Zernike coefficient time series and their corresponding temporal power spectrums. The characteristics of these results were compared to the results obtained from simulated atmospheric turbulence produced by a Kolmogorov atmosphere simulation. A low-frequency variation in the Zernike coefficient time series is observed in the pseudo open-loop phase maps reconstructed from the GPI data, that is not present in the simulation. The effects of this are observed as differences in the relative scale of high and low frequency terms in the power spectral densities.

Date Published: 27 July 2016
PDF: 8 pages
Proc. SPIE 9906, Ground-based and Airborne Telescopes VI, 990642 (27 July 2016); doi: 10.1117/12.2234362

Published in SPIE Proceedings Vol. 9906:
Ground-based and Airborne Telescopes VI
Helen J. Hall; Roberto Gilmozzi; Heather K. Marshall, Editor(s)