title: Fast calibration of high-order adaptive optics systems.
abstract: We present a new method of calibrating adaptive optics systems that greatly reduces the required calibration time or, equivalently, improves the signal-to-noise ratio. The method uses an optimized actuation scheme with Hadamard patterns and does not scale with the number of actuators for a given noise level in the wavefront sensor channels. It is therefore highly desirable for high-order systems and/or adaptive secondary systems on a telescope without a Gregorian focal plane. In the latter case, the measurement noise is increased by the effects of the turbulent atmosphere when one is calibrating on a natural guide star.
authors.affiliation: European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Kasper
authors.forename: Enrico
authors.initials: E
authors.lastname: Fedrigo
authors.forename: Douglas P
authors.initials: DP
authors.lastname: Looze
authors.forename: Henri
authors.initials: H
authors.lastname: Bonnet
authors.forename: Liviu
authors.initials: L
authors.lastname: Ivanescu
authors.forename: Sylvain
authors.initials: S
authors.lastname: Oberti