Measuring and calibration non common path aberrations in adaptive optics assisted image-slicer based spectrographs

测量和校准基于自适应光学辅助图像切片器的光谱仪中的非常见路径像差

• 批准号: 2374716
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2374716
• 关键词: Measuring; calibration; non; common; path

The DPhil Project is part of the instrument development for ESO's Extrmely Large Telescope (ELT), namely the development of the first light, adaptive optics assisted, integral field spectrograph, HARMONIIn the context of HARMONI, the integral-field spectrograph for the E-ELT, this DPhil project deals with the calibration of a type of aberrations known as non-common path aberrations (NCPA). NCPA are caused by the difference in optical path between the science light and the light used for wavefront sensing within the Adaptive Optics system (AO). One of the most widespread state-of-the-art techniques for NCPA calibration is Phase Diversity (PD), which uses a pair of in-focus and defocused images to estimate the wavefront aberrations using a maximum likelihood approach and a model of light propagation through the optical system.HARMONI contains an optical component known as an image slicer whose role is to slice the input 2D field of view into long slits that can be fed to the spectrograph. This poses a challenge when using techniques such as PD because the behaviour of image slicers in the presence of a defocus has not been characterised in depth. The effects of image slicers on light propagation, which traditional techniques do not account for, could potentially have an impact on NCPA calibration.In this context, the general goals for this research project can be summarised as:(1) Improve the understanding of the effects of image slicers on light propagation(2) Characterize the behaviour of state-of-the-art NCPA calibration techniques in the presence of image slicers. This would help us understand their limitations and applicability to the HARMONI instrument. Potentially modify those techniques to incorporate image slicer effects(3) Develop alternative techniques for NCPA calibration that could circumvent the drawbacks of state-of-the-art algorithms(4) Experimental work: demonstrate and validate these findings with an experimental benchHARMONI is a facility instrument, and will tackle a wide variety of questions in observational astrophysics. These have direct bearing on two of STFC's three science challenges: (B) How do stars and planetary systems develop and how do they support the existence of life? and (A) How did the Universe begin and how is it evolving?. This research falls with the PPAN remit, it is part of the "Astronomy and Space Sciences" research area.

DPhil项目是ESO超大望远镜（ELT）仪器开发的一部分，即开发第一台光，自适应光学辅助积分场光谱仪HARMONI。在E-ELT的积分场光谱仪HARMONI的背景下，这个DPhil项目处理一种被称为非共径像差（NCPA）的像差的校准。在自适应光学系统（AO）中，由于科学光与用于波前传感的光之间的光路不同而引起了NCPA。相位分集（PD）是NCPA校准中最广泛使用的技术之一，它使用一对聚焦和散焦图像，使用最大似然方法和光通过光学系统传播的模型来估计波前像差。HARMONI包含一个被称为图像切片器的光学组件，其作用是将输入的2D视场切割成可以馈送到光谱仪的长缝。当使用诸如PD之类的技术时，这提出了一个挑战，因为图像切片器在散焦存在下的行为尚未深入表征。图像切片器对光传播的影响是传统技术无法考虑的，这可能会对NCPA校准产生潜在影响。在这种情况下，本研究项目的总体目标可以概括为：(1)提高对图像切片器对光传播影响的理解(2)表征最先进的NCPA校准技术在图像切片器存在下的行为。这将有助于我们了解他们的局限性和适用于HARMONI乐器。(3)开发NCPA校准的替代技术，可以规避最先进算法的缺点(4)实验工作：用实验台演示和验证这些发现。harmoni是一种设施仪器，将解决观测天体物理学中的各种问题。这些直接关系到STFC的三个科学挑战中的两个：(B)恒星和行星系统是如何发展的，它们如何支持生命的存在？(A)宇宙是如何开始的，它是如何演变的？这项研究属于PPAN的职权范围，它是“天文学和空间科学”研究领域的一部分。