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Vibrations in AO control: a short analysis of on-sky data around the world

2012; SPIE; Volume: 8447; Linguagem: Inglês

10.1117/12.925984

1996-756X

Caroline Kulcsár, Gaetano Sivo, Henri-François Raynaud, Benoît Neichel, F. Rigaut, Julian C. Christou, Andrés Guesalaga, Carlos Correia, Jean‐Pierre Véran, É. Gendron, Fabrice Vidal, Gérard Rousset, Tim Morris, Simone Esposito, Fernando Quirós-Pacheco, Guido Agapito, Enrico Fedrigo, Lorenzo Pettazzi, Richard Clare, Riccardo Muradore, Olivier Guyon, Frantz Martinache, Serge Meimon, Jean-Marc Conan,

Advanced optical system design

We present in this paper an analysis of several tip-tilt on-sky data registered on adaptive optics systems installed on different telescopes (Gemini South, William Herschel Telescope, Large Binocular Telescope, Very Large Tele­ scope, Subaru). Vibration peaks can be detected, and it is shown that their presence and location may vary, and that their origin is not always easy to determine. Mechanical solution that have been realized to mitigate vibrations are presented. Nevertheless, residual vibrations may still affect the instruments' performance, ranging from narrow high frequency vibration peaks to wide low frequency windshake-type perturbations. Power Spectral Densities (PSDs) of on-sky data are presented to evidence these features. When possible, indications are given regarding the gain in performance that could be achieved with adequate controllers accounting for vibration mitigation. Two examples of controller identification and design illustrate their ability to compensate for various types of disturbances (turbulence, windshake, vibration peaks, ...),showing a significant gain in performance.