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NFIRAOS: TMT's facility adaptive optics system

Herriot, Glen and Andersen, David and Atwood, Jennifer and Boyer, Corrine and Beauvillier, Annie and Byrnes, Peter and Conan, Rod and Ellerbroek, Brent and Fitzsimmons, Joeleff and Gilles, Luc and Hickson, Paul and Hill, Alexis and Jackson, Kate and Lardière, Olivier and Pazder, John and Pfrommer, Thomas and Reshetov, Vlad and Roberts, Scott and Véran, Jean-Pierre and Wang, Lianqi and Wevers, Ivan (2010) NFIRAOS: TMT's facility adaptive optics system. In: Adaptive Optics Systems II. Proceedings of SPIE. No.7736. Society of Photo-optical Instrumentation Engineers (SPIE) , Bellingham, WA, Art. No. 77360B. ISBN 9780819482266.

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NFIRAOS, the TMT Observatory's initial facility AO system is a multi-conjugate AO system feeding science light from 0.8 to 2.5 microns wavelength to several near-IR client instruments. NFIRAOS has two deformable mirrors optically conjugated to 0 and 11.2 km, and will correct atmospheric turbulence with 50 per cent sky coverage at the galactic pole. An important requirement is to have very low background: the plan is to cool the optics; and one DM is on a tip/tilt stage to reduce surface count. NFIRAOS' real time control uses multiple sodium laser wavefront sensors and up to three IR natural guide star tip/tilt and/or tip/tilt/focus sensors located within each client instrument. Extremely large telescopes are sensitive to errors due to the variability of the sodium layer. To reduce this sensitivity, NFIRAOS uses innovative algorithms coupled with Truth wavefront sensors to monitor a natural star at low bandwidth. It also includes an IR acquisition camera, and a high speed NGS WFS for operation without lasers. For calibration, NFIRAOS includes simulators of both natural stars at infinity and laser guide stars at varying range distance. Because astrometry is an important science programme for NFIRAOS, there is a precision pinhole mask deployable at the input focal plane. This mask is illuminated by a science wavelength and flat-field calibrator that shines light into NFIRAOS' entrance window. We report on recent effort especially including trade studies to reduce field distortion in the science path and to reduce cost and complexity.

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Additional Information:© 2010 Society of Photo-Optical Instrumentation Engineers (SPIE). The authors gratefully acknowledge the support of the TMT partner institutions. They are the Association of Canadian Universities for Research in Astronomy (ACURA), the California Institute of Technology and the University of California. This work was supported as well by the Gordon and Betty Moore Foundation, the Canada Foundation for Innovation, the Ontario Ministry of Research and Innovation, the National Research Council of Canada, the Natural Sciences and Engineering Research Council of Canada, the British Columbia Knowledge Development Fund, the Association of Universities for Research in Astronomy (AURA) and the U.S. National Science Foundation.
Group:Thirty Meter Telescope
Funding AgencyGrant Number
Association of Canadian Universities for Research in Astronomy (ACURA)UNSPECIFIED
University of CaliforniaUNSPECIFIED
Gordon and Betty Moore FoundationUNSPECIFIED
Canada Foundation for InnovationUNSPECIFIED
Ontario Ministry of Research and InnovationUNSPECIFIED
National Research Council of CanadaUNSPECIFIED
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
British Columbia Knowledge Development FundUNSPECIFIED
Association of Universities for Research in Astronomy (AURA)UNSPECIFIED
Subject Keywords:Thirty Meter Telescope, TMT, NFIRAOS, Adaptive Optics
Series Name:Proceedings of SPIE
Issue or Number:7736
Record Number:CaltechAUTHORS:20180619-161902348
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Official Citation:Glen Herriot, David Andersen, Jennifer Atwood, Corinne Boyer, Annie Beauvillier, Peter Byrnes, Rod Conan, Brent Ellerbroek, Joeleff Fitzsimmons, Luc Gilles, Paul Hickson, Alexis Hill, Kate Jackson, Olivier Lardière, John Pazder, Thomas Pfrommer, Vlad Reshetov, Scott Roberts, Jean-Pierre Véran, Lianqi Wang, Ivan Wevers, "NFIRAOS: TMT's facility adaptive optics system", Proc. SPIE 7736, Adaptive Optics Systems II, 77360B (12 July 2010); doi: 10.1117/12.857662;
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:87247
Deposited By: George Porter
Deposited On:20 Jun 2018 15:02
Last Modified:03 Oct 2019 19:53

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