Sauvage J-F, Mugnier L M, Rousset G, Fusco T
Office National d'Etudes et de Recherches Aérospatiales, Département d'optique théorique et appliquée, 29 avenue de la division Leclerc, F-92322 Châtillon, France.
J Opt Soc Am A Opt Image Sci Vis. 2010 Nov 1;27(11):A157-70. doi: 10.1364/josaa.27.00a157.
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.
在本文中，我们推导了用于自适应光学（AO）校正日冕仪成像系统的长曝光恒星图像的解析模型。该表达式考虑了日冕仪掩模上游和下游的静态像差以及湍流残余。它基于完美日冕仪模型。通过使用SPHERE仪器的设计和参数进行模拟，对该解析模型进行了验证。还将该解析模型与模拟的四象限相位掩模日冕仪进行了比较。然后，研究了其对结构函数和上游静态像差校准错误的敏感性，并量化了对系外行星可探测性的影响。最后，针对使用无参考的单幅单色图像的模拟情况，提出了一种首次反演方法。所得结果表明，相对于原始图像，行星可探测性提高了两个数量级。该解析模型在日冕仪成像中具有许多潜在应用，例如系外行星直接探测和恒星周盘观测。
