The adaptive secondary mirror for the Large Binocular Telescope: optical acceptance test and preliminary on-sky commissioning results

Autor: Enrico Pinna, Alfio Puglisi, Luca Fini, Piero Salinari, Guido Brusa, Armando Riccardi, Piero Ranfagni, Carmelo Arcidiacono, Richard A. Demers, Simone Esposito, Lorenzo Busoni, Fernando Quiros-Pacheco, Daniele Gallieni, Roberto Biasi, Marco Xompero, Runa Briguglio
Rok vydání: 2010
Předmět:
Zdroj: SPIE Proceedings.
ISSN: 0277-786X
Popis: The Large Binocular Telescope (LBT) has two adaptive secondary mirrors based on 672 voice-coil force actuators. The shape of the mirror is controlled using internal metrology based on co-located capacitive sensors. The first mirror unit is currently mounted on LBT for on-sky commissioning as part of the First Light Adaptive Optics System (FLAO). During spring-time 2009 the optical acceptance test was performed using the 14-m optical test tower at the Osservatorio Astrofisico di Arcetri (INAF) showing the capability of flattening the shell at the level of 14nm rms residual surface error. This paper reports the optical layout, calibration procedures and results of the optical acceptance test. Moreover we report the first results obtained during the early runs of FLAO commissioning showing the ability of the mirror to compensate for atmospheric turbulence with extremely high Strehl ratio values (better than 80% in H-band) as permitted by the largest number of correcting degrees of freedom currently available on-sky for astronomical telescopes.
Databáze: OpenAIRE