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The advent of large aperture arrays, such as the currently under construction Square Kilometer Array (SKA), allows for observing the universe in the radio-spectrum at unprecedented resolution and sensitivity. However, these telescopes…

Instrumentation and Methods for Astrophysics · Physics 2024-12-04 S. Wang , S. Prunet , S. Mignot , A. Ferrari

We investigate possibilities to speed up iterative algorithms for non-blind image deconvolution. We focus on algorithms in which convolution with the point-spread function to be deconvolved is used in each iteration, and aim at accelerating…

Computer Vision and Pattern Recognition · Computer Science 2013-04-29 Martin Welk , Martin Erler

The deconvolution, or cleaning, of radio interferometric images often involves computing model visibilities from a list of clean components, in order that the contribution from the model can be subtracted from the observed visibilities.…

Instrumentation and Methods for Astrophysics · Physics 2019-09-10 Chris J. Skipper , Anna M. M. Scaife , Jason D. McEwen

Deconvolution microscopy has been extensively used to improve the resolution of the wide-field fluorescent microscopy, but the performance of classical approaches critically depends on the accuracy of a model and optimization algorithms.…

Image and Video Processing · Electrical Eng. & Systems 2020-07-09 Sungjun Lim , Hyoungjun Park , Sang-Eun Lee , Sunghoe Chang , Jong Chul Ye

New telescopes like the Square Kilometre Array (SKA) will push into a new sensitivity regime and expose systematics, such as direction-dependent effects, that could previously be ignored. Current methods for handling such systematics rely…

Instrumentation and Methods for Astrophysics · Physics 2015-05-22 Michelle Lochner , Iniyan Natarajan , Jonathan T. L. Zwart , Oleg Smirnov , Bruce A. Bassett , Nadeem Oozeer , Martin Kunz

We propose a new fast algorithm for solving one of the standard formulations of frame-based image deconvolution: an unconstrained optimization problem, involving an $\ell_2$ data-fidelity term and a non-smooth regularizer. Our approach is…

Optimization and Control · Mathematics 2016-11-17 Mario A. T. Figueiredo , Jose M. Bioucas-Dias , Manya V. Afonso

With Aperture synthesis (AS) technique, a number of small antennas can assemble to form a large telescope which spatial resolution is determined by the distance of two farthest antennas instead of the diameter of a single-dish antenna.…

Solar and Stellar Astrophysics · Physics 2020-12-02 Long Xu , Wenqing Sun , Yihua Yan , Weiqiang Zhang

Since the 1970s, much of traditional interferometric imaging has been built around variations of the CLEAN algorithm, in both terminology, methodology, and algorithm development. Recent developments in applying new algorithms from convex…

Instrumentation and Methods for Astrophysics · Physics 2020-09-29 Luke Pratley , Melanie Johnston-Hollitt , Jason D. McEwen

Radio telescopes with off-axis feeds, such as the (E)VLA, suffer from "beam squint" in which the two orthogonal circular polarizations sampled have different pointing centers on the sky. Its effects are weak near the beam center but become…

Astrophysics · Physics 2008-07-02 Juan M. Uson , W. D. Cotton

We present a new algorithm to perform wide-field radio interferometric image reconstruction, with exact non-coplanar correction, that scales to big-data. This algorithm allows us to image 2 billion visibilities on 50 nodes of a computing…

Instrumentation and Methods for Astrophysics · Physics 2019-03-20 Luke Pratley , Jason D. McEwen

In recent works, compressed sensing (CS) and convex optimization techniques have been applied to radio-interferometric imaging showing the potential to outperform state-of-the-art imaging algorithms in the field. We review our latest…

Instrumentation and Methods for Astrophysics · Physics 2016-11-15 Rafael E. Carrillo , Jason D. McEwen , Yves Wiaux

In recent years, deep learning has been successfully applied in various scientific domains. Following these promising results and performances, it has recently also started being evaluated in the domain of radio astronomy. In particular,…

In this paper, we are interested in the classical problem of restoring data degraded by a convolution and the addition of a white Gaussian noise. The originality of the proposed approach is two-fold. Firstly, we formulate the restoration…

Methodology · Statistics 2015-05-13 Jean-Christophe Pesquet , Amel Benazza-Benyahia , Caroline Chaux

Lensless microscopy with coherent or partially coherent light sources is a well known imaging technique, commonly referred as digital in-line holographic microscopy. In the established methods, both the spatial and temporal coherence of…

Optics · Physics 2020-11-04 Sanjeev Kumar , Manjunatha Mahadevappa , Pranab Kumar Dutta

Dimensionality reduction is an essential technique for multi-way large-scale data, i.e., tensor. Tensor ring (TR) decomposition has become popular due to its high representation ability and flexibility. However, the traditional TR…

Numerical Analysis · Mathematics 2024-12-20 Longhao Yuan , Chao Li , Jianting Cao , Qibin Zhao

Next-generation radio interferometers, such as the Square Kilometre Array (SKA), will revolutionise our understanding of the universe through their unprecedented sensitivity and resolution. However, standard methods in radio interferometry…

Instrumentation and Methods for Astrophysics · Physics 2017-02-23 Luke Pratley , Jason D. McEwen , Mayeul d'Avezac , Rafael E. Carrillo , Alexandru Onose , Yves Wiaux

The desire for wide-field of view, large fractional bandwidth, high sensitivity, high spectral and temporal resolution has driven radio interferometry to the point of big data revolution where the data is represented in at least three…

Instrumentation and Methods for Astrophysics · Physics 2020-09-30 M. Atemkeng , O. Smirnov , C. Tasse , G. Foster , S. Makhathini

The standard imaging algorithm for interferometric radio data, CLEAN, is optimal for point source observations, but suboptimal for diffuse emission. Recently, RESOLVE, a new Bayesian algorithm has been developed, which is ideal for extended…

Instrumentation and Methods for Astrophysics · Physics 2017-02-28 Maksim Greiner , Valentina Vacca , Henrik Junklewitz , Torsten A. Enßlin

Image deblurring is an economic way to reduce certain degradations (blur and noise) in acquired images. Thus, it has become essential tool in high resolution imaging in many applications, e.g., astronomy, microscopy or computational…

Optimization and Control · Mathematics 2017-05-19 Rahul Mourya , André Ferrari , Rémi Flamary , Pascal Bianchi , Cédric Richard

The most ubiquitous form of computational aberration correction for microscopy is deconvolution. However, deconvolution relies on the assumption that the point spread function is the same across the entire field-of-view. This assumption is…

Image and Video Processing · Electrical Eng. & Systems 2025-04-30 Amit Kohli , Anastasios N. Angelopoulos , David McAllister , Esther Whang , Sixian You , Kyrollos Yanny , Federico M. Gasparoli , Bo-Jui Chang , Reto Fiolka , Laura Waller