A blind deconvolution method for ground based telescopes and Fizeau interferometers |
| |
| Institution: | 1. Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Università di Modena e Reggio Emilia, Via Campi 213/b, 41125 Modena, Italy;2. Dipartimento di Informatica, Bioingegneria, Robotica e Ingegneria dei Sistemi, Università di Genova, Via Dodecaneso 35, 16145 Genova, Italy;3. Dipartimento di Matematica e Informatica, Università di Ferrara, Via Saragat 1, 44122 Ferrara, Italy;1. Center of Advanced Study, Department of Physics, Kumaun University, Nainital 263002, India;2. Aryabhatta Research Institute of Observational Sciences, Nainital 263002, India;3. Department of Physics, Hemwati Nandan Bahuguna Govt. P.G. College, Khatima 262308, Uttarakhand, India;1. Computer Technology Application Key Lab of Yunnan Province, Kunming University of Science and Technology, Chenggong, Kunming 650500, China;2. Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011, China;3. University of Chinese Academy of Sciences, Beijing 100049, China |
| |
| Abstract: | In the case of ground-based telescopes equipped with adaptive optics systems, the point spread function (PSF) is only poorly known or completely unknown. Moreover, an accurate modeling of the PSF is in general not available. Therefore in several imaging situations the so-called blind deconvolution methods, aiming at estimating both the scientific target and the PSF from the detected image, can be useful. A blind deconvolution problem is severely ill-posed and, in order to reduce the extremely large number of possible solutions, it is necessary to introduce sensible constraints on both the scientific target and the PSF.In a previous paper we proposed a sound mathematical approach based on a suitable inexact alternating minimization strategy for minimizing the generalized Kullback–Leibler divergence, assuring global convergence. In the framework of this method we showed that an important constraint on the PSF is the upper bound which can be derived from the knowledge of its Strehl ratio. The efficacy of the approach was demonstrated by means of numerical simulations.In this paper, besides improving the previous approach by the use of a further constraint on the unknown scientific target, we extend it to the case of multiple images of the same target obtained with different PSFs. The main application we have in mind is to Fizeau interferometry. As it is known this is a special feature of the Large Binocular Telescope (LBT). Of the two expected interferometers for LBT, one, LINC-NIRVANA, is forthcoming while the other, LBTI, is already operating and has provided the first Fizeau images, demonstrating the possibility of reaching the resolution of a 22.8 m telescope. Therefore the extension of our blind method to this imaging modality seems to be timely.The method is applied to realistic simulations of imaging both by single mirrors and Fizeau interferometers. Successes and failures of the method in the imaging of stellar fields are demonstrated in simple cases. These preliminary results look promising at least in specific situations. The IDL code of the proposed method is available on request and will be included in the forthcoming version of the Software Package AIRY (v.6.1). |
| |
| Keywords: | Blind deconvolution Numerical optimization Image reconstruction Fizeau interferometers |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
