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We examine whether or not it is possible to derive the field strength distribution of quiet Sun internetwork regions from very high spatial resolution polarimetric observations in the visible. In particular, we consider the case of the…

Astrophysics · Physics 2009-11-13 D. Orozco Suarez , L. R. Bellot Rubio , J. C. del Toro Iniesta

A major issue in optical astronomical image analysis is the combined effect of the instrument's point spread function (PSF) and the atmospheric seeing that blurs images and changes their shape in a way that is band and time-of-observation…

Instrumentation and Methods for Astrophysics · Physics 2024-10-02 Sreevarsha Sreejith , Anže Slosar , Hong Wang

Radio astronomical observations have very poor signal to noise ratios, unlike in other disciplines. On the other hand, it is possible to observe the object of interest for long time intervals as well as using a wider bandwidth.…

Astrophysics · Physics 2008-09-02 Sarod Yatawatta

Images from adaptive optics systems are generally affected by significant distortions of the point spread function (PSF) across the field of view, depending on the position of natural and artificial guide stars. Image reduction techniques…

Instrumentation and Methods for Astrophysics · Physics 2015-06-24 Andrea La Camera , Laura Schreiber , Emiliano Diolaiti , Patrizia Boccacci , Mario Bertero , Michele Bellazzini , Paolo Ciliegi

I propose a spatial-mode demultiplexing (SPADE) measurement scheme for the far-field imaging of spatially incoherent optical sources. For any object too small to be resolved by direct imaging under the diffraction limit, I show that SPADE…

Optics · Physics 2017-03-01 Mankei Tsang

Resolving fine details of astronomical objects provides critical insights into their underlying physical processes. This drives in part the desire to construct ever-larger telescopes and interferometer arrays and to observe at shorter…

Optical microscopy is an essential tool in biology and medicine. Imaging thin, yet non-flat objects in a single shot (without relying on more sophisticated sectioning setups) remains challenging as the shallow depth of field that comes with…

Image and Video Processing · Electrical Eng. & Systems 2020-10-14 Adrian Shajkofci , Michael Liebling

A multiscale representation-based denoising method for spherical data contaminated with Poisson noise, the multiscale variance stabilizing transform on the sphere (MS-VSTS), has been previously proposed. This paper first extends this…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Jérémy Schmitt , Jean-Luc Starck , Jean-Marc Casandjian , Jalal Fadili , Isabelle Grenier

In this paper we describe a self-contained method for performing the spectral-imaging deconvolution of X-ray data on clusters of galaxies observed by the ASCA satellite. Spatially-resolved spectral studies of data from this satellite…

Astrophysics · Physics 2009-10-31 D. A. White , D. Buote

Coronagraphic imaging in combination with moderate to high spectral resolution may prove more effective in both detecting extrasolar planets and characterizing them than a standard coronagraphic imaging approach. We envisage an…

Astrophysics · Physics 2009-11-07 William B. Sparks , Holland C. Ford

We report on the initial results obtained with an image convolution/deconvolution computer code that we developed and used to study the image formation capabilities of the solar gravitational lens (SGL). Although the SGL of a spherical Sun…

General Relativity and Quantum Cosmology · Physics 2021-06-15 Viktor T. Toth , Slava G. Turyshev

We propose a new point-spread function (PSF) deconvolution algorithm for images of galaxies hosting an active galactic nucleus (AGN), designed to simultaneously enhance the spatial resolution of the host galaxy and remove the bright central…

Astrophysics of Galaxies · Physics 2026-05-15 Ren Kawase , Takatoshi Shibuya , Kazunori Matsuda

The topology and dynamics of the solar chromosphere are greatly affected by the presence of magnetic fields. The magnetic field can be inferred by analyzing polarimetric observations of spectral lines. Polarimetric signals induced by…

Solar and Stellar Astrophysics · Physics 2019-09-11 C. J. Díaz Baso , J. de la Cruz Rodríguez , S. Danilovic

Multispectral imaging plays an important role in many applications from astronomical imaging, earth observation to biomedical imaging. However, the current technologies are complex with multiple alignment-sensitive components, predetermined…

Optics · Physics 2021-09-17 Sujit Kumar Sahoo , Dongliang Tang , Cuong Dang

We seek to find a shapelet-based scheme for deconvolving galaxy images from the PSF which leads to unbiased shear measurements. Based on the analytic formulation of convolution in shapelet space, we construct a procedure to recover the…

Astrophysics · Physics 2015-03-03 Peter Melchior , Rene Andrae , Matteo Maturi , Matthias Bartelmann

In order to produce high dynamic range images in radio interferometry, bright extended sources need to be removed with minimal error. However, this is not a trivial task because the Fourier plane is sampled only at a finite number of…

Instrumentation and Methods for Astrophysics · Physics 2011-01-17 Sarod Yatawatta

We study the image formation process with the solar gravitational lens (SGL) in the case of an extended, resolved source. An imaging telescope, modeled as a convex lens, is positioned within the image cylinder formed by the light received…

Instrumentation and Methods for Astrophysics · Physics 2020-07-31 Slava G. Turyshev , Viktor T. Toth

In this paper we propose a blind deconvolution method which applies to data perturbed by Poisson noise. The objective function is a generalized Kullback-Leibler divergence, depending on both the unknown object and unknown point spread…

Instrumentation and Methods for Astrophysics · Physics 2013-11-25 M. Prato , A. La Camera , S. Bonettini , M. Bertero

Image subtraction is essential for transient detection in time-domain astronomy. The point spread function (PSF), photometric scaling, and sky background generally vary with time and across the field-of-view for imaging data taken with…

Instrumentation and Methods for Astrophysics · Physics 2022-09-14 Lei Hu , Lifan Wang , Xingzhuo Chen , Jiawen Yang

Recovering sharper images from blurred observations, referred to as deconvolution, is an ill-posed problem where classical approaches often produce unsatisfactory results. In ground-based astronomy, combining multiple exposures to achieve…

Computer Vision and Pattern Recognition · Computer Science 2025-10-07 Fausto Navarro , Daniel Hall , Tamas Budavari , Yashil Sukurdeep