Abstract
In this paper we derive an analytical model of a long-exposure star image for an adaptive-optics(AO)-corrected coronagraphic imaging system. This expression accounts for static aberrations upstream and downstream of the coronagraphic mask as well as turbulence residuals. It is based on the perfect coronagraph model. The analytical model is validated by means of simulations using the design and parameters of the SPHERE instrument. The analytical model is also compared to a simulated four-quadrant phase-mask coronagraph. Then, its sensitivity to a miscalibration of structure function and upstream static aberrations is studied, and the impact on exoplanet detectability is quantified. Last, a first inversion method is presented for a simulation case using a single monochromatic image with no reference. The obtained result shows a planet detectability increase by two orders of magnitude with respect to the raw image. This analytical model presents numerous potential applications in coronographic imaging, such as exoplanet direct detection, and circumstellar disk observation.
© 2010 Optical Society of America
Full Article | PDF ArticleMore Like This
Szymon Gladysz, Natalia Yaitskova, and Julian C. Christou
J. Opt. Soc. Am. A 27(11) A64-A75 (2010)
Laurent M. Mugnier, Alberto Cornia, Jean-François Sauvage, Gérard Rousset, Thierry Fusco, and Nicolas Védrenne
J. Opt. Soc. Am. A 26(6) 1326-1334 (2009)
Laurent M. Mugnier, Thierry Fusco, and Jean-Marc Conan
J. Opt. Soc. Am. A 21(10) 1841-1854 (2004)