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Real-time estimation and correction of quasi-static aberrations in ground-based high contrast imaging systems with high frame-rates

Rodack, Alexander T. and Males, Jared R. and Guyon, Olivier and Mazin, Benjamin A. and Fitzgerald, Michael P. and Mawet, Dimitri (2018) Real-time estimation and correction of quasi-static aberrations in ground-based high contrast imaging systems with high frame-rates. In: Adaptive Optics Systems VI. Proceedings of SPIE. No.10703. Society of Photo-optical Instrumentation Engineers (SPIE) , Bellingham, WA, Art. No. 107032N. ISBN 9781510619593.

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The success of ground-based, high contrast imaging for the detection of exoplanets in part depends on the ability to differentiate between quasi-static speckles caused by aberrations not corrected by adaptive optics (AO) systems, known as non-common path aberrations (NCPAs), and the planet intensity signal. Frazin (ApJ, 2013) introduced a post-processing algorithm demonstrating that simultaneous millisecond exposures in the science camera and wavefront sensor (WFS) can be used with a statistical inference procedure to determine both the series expanded NCPA coefficients and the planetary signal. We demonstrate, via simulation, that using this algorithm in a closed-loop AO system, real-time estimation and correction of the quasi-static NCPA is possible without separate deformable mirror (DM) probes. Thus the use of this technique allows for the removal of the quasi-static speckles that can be mistaken for planetary signals without the need for new optical hardware, improving the efficiency of ground-based exoplanet detection. In our simulations, we explore the behavior of the Frazin Algorithm (FA) and the dependence of its convergence to an accurate estimate on factors such as Strehl ratio, NCPA strength, and number of algorithm search basis functions. We then apply this knowledge to simulate running the algorithm in real-time in a nearly ideal setting. We then discuss adaptations that can be made to the algorithm to improve its real-time performance, and show their efficacy in simulation. A final simulation tests the technique’s resilience against imperfect knowledge of the AO residual phase, motivating an analysis of the feasibility of using this technique in a real closed-loop Extreme AO system such as SCExAO or MagAO-X, in terms of computational complexity and the accuracy of the estimated quasi-static NCPA correction.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Guyon, Olivier0000-0002-1097-9908
Fitzgerald, Michael P.0000-0002-0176-8973
Mawet, Dimitri0000-0002-8895-4735
Additional Information:© 2018 Society of Photo-Optical Instrumentation Engineers (SPIE). This work was supported in part by NSF ATI Award #1710356 and by NSF MRI Award #1625441. The authors would also like to thank Dr. Richard A. Frazin for his work developing the base algorithm and his support in our endeavors.
Group:Astronomy Department
Funding AgencyGrant Number
Subject Keywords:High contrast imaging, Extreme adaptive optics, Active speckle control, Quasi-static speckles, Exoplanets
Series Name:Proceedings of SPIE
Issue or Number:10703
Record Number:CaltechAUTHORS:20180712-153453502
Persistent URL:
Official Citation:Alexander T. Rodack, Jared R. Males, Olivier Guyon, Benjamin A. Mazin, Michael P. Fitzgerald, Dimitri Mawet, "Real-time estimation and correction of quasi-static aberrations in ground-based high contrast imaging systems with high frame-rates", Proc. SPIE 10703, Adaptive Optics Systems VI, 107032N (10 July 2018); doi: 10.1117/12.2312218;
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:87812
Deposited By: George Porter
Deposited On:13 Jul 2018 17:30
Last Modified:15 Nov 2021 20:52

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