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Simultaneous Water Vapor and Dry Air Optical Path Length Measurements and Compensation with the Large Binocular Telescope InterferometerThe Large Binocular Telescope Interferometer uses a near-infrared camera to measure the optical path length variations between the two AO-corrected apertures and provide high-angular resolution observations for all its science channels (1.5-13 microns). There is however a wavelength dependent component to the atmospheric turbulence, which can introduce optical path length errors when observing at a wavelength different from that of the fringe sensing camera. Water vapor in particular is highly dispersive and its effect must be taken into account for high-precision infrared interferometric observations as described previously for VLTI/MIDI or the Keck Interferometer Nuller. In this paper, we describe the new sensing approach that has been developed at the LBT to measure and monitor the optical path length fluctuations due to dry air and water vapor separately. After reviewing the current performance of the system for dry air seeing compensation, we present simultaneous H-, K-, and N-band observations that illustrate the feasibility of our feed forward approach to stabilize the path length fluctuations seen by the LBTI nuller uses a near-infrared camera to measure the optical path length variations between the two AO-corrected apertures and provide high-angular resolution observations for all its science channels (1.5-13 microns). There is however a wavelength dependent component to the atmospheric turbulence, which can introduce optical path length errors when observing at a wavelength different from that of the fringe sensing camera. Water vapor in particular is highly dispersive and its effect must be taken into account for high-precision infrared interferometric observations as described previously for VLTI MIDI or the Keck Interferometer Nuller. In this paper, we describe the new sensing approach that has been developed at the LBT to measure and monitor the optical path length fluctuations due to dry air and water vapor separately. After reviewing the current performance of the system for dry air seeing compensation, we present simultaneous H-, K-, and N-band observations that illustrate the feasibility of our feed forward approach to stabilize the path length fluctuations seen by the LBTI nuller.
Document ID
20170006061
Document Type
Conference Paper
External Source(s)
Authors
Defrere, D.
(Liege Univ. Belgium)
Hinz, P.
(Arizona Univ. Tucson, AZ, United States)
Downey, E.
(Liege Univ. Belgium)
Boehm, M.
(Technische Hochschule Stuttgart, Germany)
Danchi, W. C.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Durney, O.
(Arizona Univ. Tucson, AZ, United States)
Ertel, S.
(Arizona Univ. Tucson, AZ, United States)
Hill, J. M.
(Arizona Univ. Tucson, AZ, United States)
Hoffmann, W. F.
(Arizona Univ. Tucson, AZ, United States)
Mennesson, B.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Millan-Gabet, R.
(California Inst. of Tech. Pasadena, CA, United States)
Montoya, M.
(Arizona Univ. Tucson, AZ, United States)
Pott, J.-U.
(Max-Planck-Inst. fuer Astronomie Heidelberg, Germany)
Skemer, A.
(California Univ. Santa Cruz, CA, United States)
Spalding, E.
(Arizona Univ. Tucson, AZ, United States)
Stone, J.
(Arizona Univ. Tucson, AZ, United States)
Vaz, A.
(Arizona Univ. Tucson, AZ, United States)
Date Acquired
July 3, 2017
Publication Date
June 26, 2016
Publication Information
Publication: SPIE Conference Proceedings
Volume: 9907
ISSN: 0277-786X
Subject Category
Astrophysics
Report/Patent Number
GSFC-E-DAA-TN43767
Meeting Information
Optical and Infrared Interferometry and Imaging V(Edinburgh)
Distribution Limits
Public
Copyright
Other
Keywords
which can introduce optical path length errors when observing at a wavelength d
The Large Binocular Telescope Interferometer uses a near-infrared camera to meas
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