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arXiv 2303.09422astro-ph.IMastro-ph.EPastro-ph.SR
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改进的自适应光学点扩散函数估计先验:用于科学图像反卷积的应用

Improved prior for adaptive optics point spread function estimation from science images: Application for deconvolution

A. Lau, R. JL. Fétick, B. Neichel, O. Beltramo-Martin, T. Fusco

AI总结:

本研究改进自适应光学图像PSF估计的边际算法,通过增强物体先验,实现对延展天体的稳健盲反卷积,并在模拟及Kleopatra小行星观测中验证了方法的有效性。

摘要:

自适应光学(AO)辅助观测的点扩散函数(PSF)知识获取仍然是处理AO数据时的一个主要限制。当图像分析需要使用反卷积方法时,这一限制尤为突出。由于PSF是一个复杂且随时间变化的函数,在科学观测之前或之后于定标星上获取的参考PSF可能与观测的实际PSF差异过大,无法用于反卷积,并导致最终图像中出现伪影。我们通过增强物体先验,改进了基于所谓边际方法的现有PSF估计方法,使其更加稳健且适用于分辨的延展天体观测。我们的过程基于文献中的两步盲反卷积方法。第一步包括从科学图像中估计PSF。为此,我们使用了解析PSF模型,其参数基于边际算法进行估计。随后将该PSF用于反卷积。在本研究中,我们首先通过模拟研究了在PSF参数知识方面获得准确且具有弹性的反卷积过程所需的条件。我们表明,现有边际算法无法提供所需的精度,尤其是在存在小天体的情况下。因此,我们通过提供新的物体描述模型来修改边际算法,从而改进所需PSF参数的估计。我们的方法在模拟中满足了对现实系统配置和不同类别太阳系天体的反卷积要求。最后,我们通过对小行星Kleopatra的SPHERE/ZIMPOL观测进行盲反卷积来验证我们的方法。

英文摘要:

Access to knowledge of the point spread function (PSF) of adaptive optics(AO)-assisted observations is still a major limitation when processing AO data. This limitation is particularly important when image analysis requires the use of deconvolution methods. As the PSF is a complex and time-varying function, reference PSFs acquired on calibration stars before or after the scientific observation can be too different from the actual PSF of the observation to be used for deconvolution, and lead to artefacts in the final image. We improved the existing PSF-estimation method based on the so-called marginal approach by enhancing the object prior in order to make it more robust and suitable for observations of resolved extended objects. Our process is based on a two-step blind deconvolution approach from the literature. The first step consists of PSF estimation from the science image. For this, we made use of an analytical PSF model, whose parameters are estimated based on a marginal algorithm. This PSF was then used for deconvolution. In this study, we first investigated the requirements in terms of PSF parameter knowledge to obtain an accurate and yet resilient deconvolution process using simulations. We show that current marginal algorithms do not provide the required level of accuracy, especially in the presence of small objects. Therefore, we modified the marginal algorithm by providing a new model for object description, leading to an improved estimation of the required PSF parameters. Our method fulfills the deconvolution requirement with realistic system configurations and different classes of Solar System objects in simulations. Finally, we validate our method by performing blind deconvolution with SPHERE/ZIMPOL observations of the Kleopatra asteroid.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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