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

Alexander T. Rodack, Jared R. Males, Olivier Guyon, Benjamin A. Mazin, Michael P. Fitzgerald, Dimitri Mawet

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations

Abstract

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.

Original languageEnglish (US)
Title of host publicationAdaptive Optics Systems VI
EditorsDirk Schmidt, Laura Schreiber, Laird M. Close
PublisherSPIE
ISBN (Print)9781510619593
DOIs
StatePublished - 2018
EventAdaptive Optics Systems VI 2018 - Austin, United States
Duration: Jun 10 2018Jun 15 2018

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume10703
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X

Other

OtherAdaptive Optics Systems VI 2018
CountryUnited States
CityAustin
Period6/10/186/15/18

Keywords

  • Active speckle control
  • Exoplanets
  • Extreme adaptive optics
  • High contrast imaging
  • Quasi-static speckles

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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