TY - GEN
T1 - Real-time estimation and correction of quasi-static aberrations in ground-based high contrast imaging systems with high frame-rates
AU - Rodack, Alexander T.
AU - Males, Jared R.
AU - Guyon, Olivier
AU - Mazin, Benjamin A.
AU - Fitzgerald, Michael P.
AU - Mawet, Dimitri
N1 - Funding Information:
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.
Publisher Copyright:
© 2018 SPIE.
PY - 2018
Y1 - 2018
N2 - 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.
AB - 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.
KW - Active speckle control
KW - Exoplanets
KW - Extreme adaptive optics
KW - High contrast imaging
KW - Quasi-static speckles
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U2 - 10.1117/12.2312218
DO - 10.1117/12.2312218
M3 - Conference contribution
AN - SCOPUS:85053527731
SN - 9781510619593
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Adaptive Optics Systems VI
A2 - Schmidt, Dirk
A2 - Schreiber, Laura
A2 - Close, Laird M.
PB - SPIE
T2 - Adaptive Optics Systems VI 2018
Y2 - 10 June 2018 through 15 June 2018
ER -