Focal-plane wavefront sensing for active optics in the VST based on an analytical optical aberration model
Date Issued
2016
Author(s)
Abstract
We study a novel focal plane wavefront sensing and active optics control scheme at the VST on Cerro Paranal, an f/5.5 survey telescope with a 1x1 degree field of view and a 2.6m primary mirror. This scheme analyzes the elongation pattern of stellar PSFs across the full science image (256 Mpixels) and compares their second moments with an analytical model based on 5th-order geometrical optics. We consider 11 scalar degrees of freedom in mirror misalignments and deformations (M2 piston, tip/tilt and lateral displacement, detector tip/tilt, plus M1 figure astigmatism and trefoil). Using a numerical optimization method, we extract up to 4000 stars and complete the fitting process in under one minute. We demonstrate successful closed-loop active optics control based on maximum likelihood filtering.
Coverage
Ground-based and Airborne Telescopes VI
All editors
Hall, Helen J.; Gilmozzi, Roberto; Marshall, Heather K.
Series
Volume
9906
Start page
99066E
Conferenece
Ground-based and Airborne Telescopes VI
Conferenece place
Edinburgh, United Kingdom
Conferenece date
26 June - 1 July 2016
Issn Identifier
0277-786X
Ads BibCode
2016SPIE.9906E..6EH
Rights
open.access
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