Holzlöhner, R.R.HolzlöhnerTaubenberger, S.S.TaubenbergerRakich, A. P.A. P.RakichNoethe, L.L.NoetheSCHIPANI, PietroPietroSCHIPANIKuijken, K.K.Kuijken2020-06-112020-06-11201697815106019180277-786Xhttp://hdl.handle.net/20.500.12386/26010We 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.STAMPAenConference paper10.1117/12.22343982-s2.0-85001070003000387731100196https://www.spiedigitallibrary.org/conference-proceedings-of-spie/9906/1/Focal-plane-wavefront-sensing-for-active-optics-in-the-VST/10.1117/12.2234398.short2016SPIE.9906E..6EHFIS/05 - ASTRONOMIA E ASTROFISICA