The Subaru coronagraphic extreme AO (SCExAO) system: Visible imaging mode

Vincent Garrei, Olivier Guyon, Pierre Baudoz, Frantz Martinache, Frederic Vogt, Yoshikawa Takashi, Yokochi Kaito, Faustine Cantalloube

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

2 Scopus citations


The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system is an instrument designed to be inserted between the Subaru AO188 system and the infrared HiCIAO camera in order to greatly improve the contrast in the very close (less than 0.5") neighbourhood of stars. Next to the infrared coronagraphic path, a visible scientific path, based on a EMCCD camera, has been implemented. Benefiting from both Adaptive Optics (AO) correction and new data processing techniques, it is a powerful tool for high angular resolution imaging and opens numerous new science opportunities. We propose here a new image processing algorithm, based on the selection of the best signal for each spatial frequency. A factor 2 to 3 in Střehl ratio is obtained compared to the AO long exposure time depending on the image processing algorithm used and the seeing conditions. The system is able to deliver diffraction limited images at 650 nm (17 mas FWHM).We also demonstrate that this approach offers significantly better results than the classical select, shift and add approach (lucky imaging).

Original languageEnglish (US)
Title of host publicationAdaptive Optics Systems II
EditionPART 1
StatePublished - 2010
EventAdaptive Optics Systems II - San Diego, CA, United States
Duration: Jun 27 2010Jul 2 2010

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
NumberPART 1
ISSN (Print)0277-786X


OtherAdaptive Optics Systems II
Country/TerritoryUnited States
CitySan Diego, CA


  • Adaptive optics methods
  • Data analysis techniques
  • High angular resolution instrumentation
  • High angular resolution techniques
  • Image processing
  • Instrumentation

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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