Paper published in a book (Scientific congresses and symposiums)
A two-band approach to nλ phase error corrections with LBTI's PHASECam
Maier, E. R.; Hinz, P. M.; Defrere, Denis et al.
2018In Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series
 

Files


Full Text
1807.04786.pdf
Author preprint (1.93 MB)
Download

All documents in ORBi are protected by a user license.

Send to



Details



Keywords :
Fringe sensing; LBTI; LBT; Exoplanet; Exozodi
Abstract :
[en] PHASECam is the Large Binocular Telescope Interferometer's (LBTI) phase sensor, a near-infrared camera which is used to measure tip/tilt and phase variations between the two AO-corrected apertures of the Large Binocular Telescope (LBT). Tip/tilt and phase sensing are currently performed in the H (1.65 μm) and K (2.2 μm) bands at 1 kHz, and the K band phase telemetry is used to send tip/tilt and Optical Path Difference (OPD) corrections to the system. However, phase variations outside the range [-Π, Π] are not sensed, and thus are not fully corrected during closed-loop operation. PHASECam's phase unwrapping algorithm, which attempts to mitigate this issue, still occasionally fails in the case of fast, large phase variations. This can cause a fringe jump, in which case the unwrapped phase will be incorrect by a wavelength or more. This can currently be manually corrected by the observer, but this is inefficient. A more reliable and automated solution is desired, especially as the LBTI begins to commission further modes which require robust, active phase control, including controlled multi-axial (Fizeau) interferometry and dual-aperture non-redundant aperture masking interferometry. We present a multi-wavelength method of fringe jump capture and correction which involves direct comparison between the K band and currently unused H band phase telemetry.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Maier, E. R.;  Steward Observatory, The Univ. of Arizona (United States)
Hinz, P. M.;  Steward Observatory, The Univ. of Arizona (United States)
Defrere, Denis ;  Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > ISSPSILAB
Ertel, S.;  Steward Observatory, The Univ. of Arizona (United States)
Downey, E.;  Steward Observatory, The Univ. of Arizona (United States))
Language :
English
Title :
A two-band approach to nλ phase error corrections with LBTI's PHASECam
Publication date :
01 July 2018
Event name :
2018 Optical and Infrared Interferometry and Imaging VI
Event date :
11 June 2018 through 15 June 2018
Audience :
International
Main work title :
Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series
ISBN/EAN :
9781510619555
Commentary :
ISBN: 0701
Available on ORBi :
since 23 October 2018

Statistics


Number of views
44 (3 by ULiège)
Number of downloads
110 (3 by ULiège)

Scopus citations®
 
4
Scopus citations®
without self-citations
0
OpenCitations
 
1

Bibliography


Similar publications



Contact ORBi