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In a companion paper, we presented BayesCal, a mathematical formalism for mitigating sky-model incompleteness in interferometric calibration. In this paper, we demonstrate the use of BayesCal to calibrate the degenerate gain parameters of…

Instrumentation and Methods for Astrophysics · Physics 2022-07-20 Peter H. Sims , Jonathan C. Pober , Jonathan L. Sievers

Methods currently in use for locating and characterising sources in radio interferometry maps are designed for processing images, and require interferometric maps to be preprocessed so as to resemble conventional images. We demonstrate a…

Instrumentation and Methods for Astrophysics · Physics 2018-12-26 Peter Hague , Haoyang Ye , Bojan Nikolic , Steve Gull

Deconvolution, imaging and calibration of data from radio interferometers is a challenging computational (inverse) problem. The upcoming generation of radio telescopes poses significant challenges to existing, and well proven data reduction…

Instrumentation and Methods for Astrophysics · Physics 2025-06-18 Hendrik Müller , Sanjay Bhatnagar

Detection of millikelvin-level signals from the 'Cosmic Dawn' requires an unprecedented level of sensitivity and systematic calibration. We report the theory behind a novel calibration algorithm developed from the formalism introduced by…

Instrumentation and Methods for Astrophysics · Physics 2022-09-15 I. L. V. Roque , W. J. Handley , N. Razavi-Ghods

Very long baseline interferometry (VLBI) is a radio-astronomical technique in which the correlated signal from various baselines is combined into an image of highest angular resolution. Due to sparsity of the measurements, this imaging…

Instrumentation and Methods for Astrophysics · Physics 2023-03-29 Hendrik Müller , Andrei Lobanov

Machine learning methods for computational imaging require uncertainty estimation to be reliable in real settings. While Bayesian models offer a computationally tractable way of recovering uncertainty, they need large data volumes to be…

Machine Learning · Computer Science 2020-08-24 Francesco Tonolini , Jack Radford , Alex Turpin , Daniele Faccio , Roderick Murray-Smith

Flux calibration of spectra in reverberation mapping (RM) is most often performed by assuming the flux constancy of some specified narrow emission lines, which stem from an extended region that is sometimes partially spatially resolved, in…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 Yan-Rong Li , Jian-Min Wang , Chen Hu , Pu Du , Jin-Ming Bai

We propose a new technique to obtain super-resolution images with radio interferometer using sparse modeling. In standard radio interferometry, sampling of ($u$, $v$) is quite often incomplete and thus obtaining an image from observed…

Instrumentation and Methods for Astrophysics · Physics 2014-07-10 Mareki Honma , Kazunori Akiyama , Makoto Uemura , Shiro Ikeda

Infrared and visible image fusion has been a hot issue in image fusion. In this task, a fused image containing both the gradient and detailed texture information of visible images as well as the thermal radiation and highlighting targets of…

Computer Vision and Pattern Recognition · Computer Science 2020-09-04 Zixiang Zhao , Shuang Xu , Chunxia Zhang , Junmin Liu , Jiangshe Zhang

We propose a new approach within the versatile framework of convex optimization to solve the radio-interferometric wideband imaging problem. Our approach, dubbed HyperSARA, solves a sequence of weighted nuclear norm and l21 minimization…

Image and Video Processing · Electrical Eng. & Systems 2019-09-11 Abdullah Abdulaziz , Arwa Dabbech , Yves Wiaux

A radio interferometer indirectly measures the intensity distribution of the sky over the celestial sphere. Since measurements are made over an irregularly sampled Fourier plane, synthesising an intensity image from interferometric…

Instrumentation and Methods for Astrophysics · Physics 2014-03-18 Daniel Muscat

Interferometric radio astronomy data require the effects of limited coverage in the Fourier plane to be accounted for via a deconvolution process. For the last 40 years this process, known as `cleaning', has been performed almost…

Instrumentation and Methods for Astrophysics · Physics 2016-06-15 Luke Pratley , Melanie Johnston-Hollitt

We present a principled Bayesian framework for signal reconstruction, in which the signal is modelled by basis functions whose number (and form, if required) is determined by the data themselves. This approach is based on a Bayesian…

Instrumentation and Methods for Astrophysics · Physics 2019-01-23 Edward Higson , Will Handley , Michael Hobson , Anthony Lasenby

With a Bayesian approach, the linear optics correction algorithm for storage rings is revisited. Starting from the Bayes' theorem, a complete linear optics model is simplified as "likelihood functions" and "prior probability distributions".…

Accelerator Physics · Physics 2019-04-18 Yongjun Li , Robert Rainer , Weixing Cheng

Crossmatching catalogs at different wavelengths is a difficult problem in astronomy, especially when the objects are not point-like. At radio wavelengths an object can have several components corresponding, for example, to a core and lobes.…

Instrumentation and Methods for Astrophysics · Physics 2015-05-05 Dongwei Fan , Tamás Budavári , Ray P. Norris , Andrew M. Hopkins

Autonomous methods to align beamlines can decrease the amount of time spent on diagnostics, and also uncover better global optima leading to better beam quality. The alignment of these beamlines is a high-dimensional, expensive-to-sample…

We present a comparison of image and uv-plane galaxy-galaxy strong lensing modelling results for simulated ALMA observations with different antenna configurations and on-source integration times. Image-plane modelling is carried out via use…

Astrophysics of Galaxies · Physics 2025-07-08 Jacob Maresca , Simon Dye

The increased sensitivity of future radio telescopes will result in requirements for higher dynamic range within the image as well as better resolution and immunity to interference. In this paper we propose a new matrix formulation of the…

Astrophysics · Physics 2014-11-18 Chen Ben-David , Amir Leshem

We describe a "spatio-spectral" deconvolution algorithm for wide-band imaging in radio interferometry. In contrast with the existing multi-frequency reconstruction algorithms, the proposed method does not rely on a model of the…

Instrumentation and Methods for Astrophysics · Physics 2016-03-01 André Ferrari , Jérémy Deguignet , Chiara Ferrari , David Mary , Antony Schutz , Oleg Smirnov

Modeling statistics of image priors is useful for image super-resolution, but little attention has been paid from the massive works of deep learning-based methods. In this work, we propose a Bayesian image restoration framework, where…

Image and Video Processing · Electrical Eng. & Systems 2022-04-05 Shangqi Gao , Xiahai Zhuang