title: Calibrating the interaction matrix for the LINC-NIRVANA high layer wavefront sensor.
abstract: LINC-NIRVANA is a near-infrared Fizeau interferometric imager that will operate at the Large Binocular Telescope. In preparation for the commissioning of this instrument, we conducted experiments for calibrating the high-layer wavefront sensor of the layer-oriented multi-conjugate adaptive optics system. For calibrating the multi-pyramid wavefront sensor, four light sources were used to simulate guide stars. Using this setup, we developed the push-pull method for calibrating the interaction matrix. The benefits of this method over the traditional push-only method are quantified, and also the effects of varying the number of push-pull frames over which aberrations are averaged is reported. Finally, we discuss a method for measuring mis-conjugation between the deformable mirror and the wavefront sensor, and the proper positioning of the wavefront sensor detector with respect to the four pupil positions.
authors.affiliation: Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg,Germany. zhang@mpia.de
authors.forename: Xianyu
authors.initials: X
authors.lastname: Zhang
authors.forename: Carmelo
authors.initials: C
authors.lastname: Arcidiacono
authors.forename: Albert R
authors.initials: AR
authors.lastname: Conrad
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Herbst
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Gaessler
authors.forename: Thomas
authors.initials: T
authors.lastname: Bertram
authors.forename: Roberto
authors.initials: R
authors.lastname: Ragazzoni
authors.forename: Laura
authors.initials: L
authors.lastname: Schreiber
authors.forename: Emiliano
authors.initials: E
authors.lastname: Diolaiti
authors.forename: Martin
authors.initials: M
authors.lastname: Kuerster
authors.forename: Peter
authors.initials: P
authors.lastname: Bizenberger
authors.forename: Daniel
authors.initials: D
authors.lastname: Meschke
authors.forename: Hans-Walter
authors.initials: HW
authors.lastname: Rix
authors.forename: Changhui
authors.initials: C
authors.lastname: Rao
authors.forename: Lars
authors.initials: L
authors.lastname: Mohr
authors.forename: Florian
authors.initials: F
authors.lastname: Briegel
authors.forename: Frank
authors.initials: F
authors.lastname: Kittmann
authors.forename: Juergen
authors.initials: J
authors.lastname: Berwein
authors.forename: Jan
authors.initials: J
authors.lastname: Trowitzsch
mesh_terms: D002138:Calibration; D007368:Interferometry / Q000295:instrumentation*; D010783:Photometry / Q000295:instrumentation*; D061351:Telescopes; D014159:Transducers