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额外大型望远镜（ELT）的仪器开发的一部分，即第一光的开发，自适应光学辅助，整体场谱仪，Harmoniin，Harmoni the Harmoni的环境，Harmoni的环境，ETELT的整体场频谱仪，该dphil项目涉及已知类型的aberon comment（noncommon）。 NCPA是由科学光和用于自适应光学系统（AO）中波前传感的光之间的光路差异引起的。 NCPA校准最广泛的最新技术之一是相位多样性（PD），它使用一对聚焦和散焦的图像来估算使用最大的可能性方法和通过光学系统的光传播模型来估算波前畸变。喂给光谱仪。当使用PD等技术时，这构成了一个挑战，因为在存在散焦的情况下图像切片机的行为尚未被深入表征。传统技术无法解释的图像切片机对光传播的影响可能会对NCPA校准产生影响。在这种情况下，该研究项目的一般目标可以总结为：（1）提高对光繁殖的影响（2）表征现有NCPA校准技术在现场技术中的现有NCPA校准的行为的理解（2）这将有助于我们了解他们对Harmoni工具的局限性和适用性。有可能修改这些技术以结合图像切片效果（3）开发了NCPA校准的替代技术，这些技术可以避免最先进的算法的缺点（4）实验性工作：通过实验性的Benchharmoni是一种设施工具，证明并验证了这些发现，并将在各种各样的问题中解决各种各样的问题。这些直接涉及STFC的三个科学挑战中的两个：（b）恒星和行星系统如何发展以及它们如何支持生命的存在？ （a）宇宙是如何开始的，它如何发展？这项研究伴随着PPAN职权范围，它是“天文学和太空科学”研究领域的一部分。