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arXiv · 2012.11670

GRAVITY acquisition camera: characterization results

Narsireddy Anugu·Paulo Garcia·Antonio Amorim·Erich Wiezorrek·Ekkehard Wieprecht·Frank Eisenhauer·Thomas Ott·Oliver Pfuhl·Paulo Gordo·Guy Perrin·Wolfgang Brandner·Christian Straubmeierfan·Karine Perraut
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Abstract

GRAVITY acquisition camera implements four optical functions to track multiple beams of Very Large Telescope Interferometer (VLTI): a) pupil tracker: a $2 \times 2$ lenslet images four pupil reference lasers mounted on the spiders of telescope secondary mirror; b) field tracker: images science object; c) pupil imager: reimages telescope pupil; d) aberration tracker: images a Shack-Hartmann. The estimation of beam stabilization parameters from the acquisition camera detector image is carried out, for every 0.7 s, with a dedicated data reduction software. The measured parameters are used in: a) alignment of GRAVITY with the VLTI; b) active pupil and field stabilization; c) defocus correction and engineering purposes. The instrument is now successfully operational on-sky in closed loop. The relevant data reduction and on-sky characterization results are reported.

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Narsireddy Anugu, Paulo Garcia, Antonio Amorim, Erich Wiezorrek, Ekkehard Wieprecht, Frank Eisenhauer, Thomas Ott, Oliver Pfuhl, Paulo Gordo, Guy Perrin, Wolfgang Brandner, Christian Straubmeierfan, Karine Perraut. 2020-12-21. GRAVITY acquisition camera: characterization results. https://doi.org/10.1117/12.2233315

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