bandeau.png

An analytical approach to model the second-stage Adaptive Optics correction for SPHERE
Laura Schreiber  1@  , Maud Langlois, Laurent Jolissaint, Emiliano Diolaiti, Clémentine Béchet, Fausto Cortecchia, Markus Feldt, Florian Ferreira, Galicher Raphael, Goulas Charles, Kulcsar Caroline, Matteo Lombini, Loupias Magali, Mazoyer Johan, N'diaye Mamadou, Henri Francois Raynaud, Eric Stadler, Michel Tallon, Isabelle Tallon-Bosc, Eric Thiébaut, Fabrice Vidal, Anthony Boccaletti, Gael Chauvin, Raffaele Gratton, Julien Milli, David Mouillet, François Wildi@
1 : INAF - Osservatorio Astronomico di Collurania
64 100 Teramo -  Italy

SAXO+ is the name of the proposed second-stage adaptive optics module to increase the performance of the
SPHERE instrument at the Very Large Telescope (Chile). This upgrade aims at improving the raw contrast
(up to 105, goal 106) close to the optical axis (at a separation of 0.2 arcseconds, with a goal of 0.1), enabling
the observation of fainter and redder targets. SAXO+ will be implemented on a mezzanine above the main
bench and it will be fed by an exchange mechanism deploying a pick-off mirror in order to preserve all the
functionalities of the original instrument. The wavefront sensing will be based on pyramid wavefront sensor in
the near-infrared. In order to define the main requirements for the second-stage module design, a few trade-offs
need to be carried out. We present in this paper an analytical approach, based on spatial PSD analysis, to study
some error terms affecting the SAXO+ system and to directly compute the AO residual phase screens. For this
purpose, a second-stage correction filter in the spatial frequency domain has been implemented in PAOLA, a
software tool for the analytical modeling of Adaptive Optics systems.


Online user: 6 RSS Feed | Privacy
Loading...