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We present RESOLVE, a new algorithm for radio aperture synthesis imaging of extended and diffuse emission in total intensity. The algorithm is derived using Bayesian statistical inference techniques, estimating the surface brightness in the…

Instrumentation and Methods for Astrophysics · Physics 2016-02-03 H. Junklewitz , M. R. Bell , M. Selig , T. A. Enßlin

Aims : We describe MS-MFS, a multi-scale multi-frequency deconvolution algorithm for wide-band synthesis-imaging, and present imaging results that illustrate the capabilities of the algorithm and the conditions under which it is feasible…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 Urvashi Rau , Tim J. Cornwell

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

We introduce a new technique for imaging the polarized radio sky using interferometric data. The new approach, which we call Faraday synthesis, combines aperture and rotation measure synthesis imaging and deconvolution into a single…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 M. R. Bell , T. A. Enßlin

The data reduction procedure for radio interferometers can be viewed as a combined calibration and imaging problem. We present an algorithm that unifies cross-calibration, self-calibration, and imaging. Being a Bayesian method, that…

Instrumentation and Methods for Astrophysics · Physics 2019-07-23 Philipp Arras , Philipp Frank , Reimar Leike , Rüdiger Westermann , Torsten Enßlin

Modern radio interferometers deliver large volumes of data containing high-sensitivity sky maps over wide fields-of-view. These large area observations can contain various and superposed structures such as point sources, extended objects,…

Instrumentation and Methods for Astrophysics · Physics 2025-12-05 Richard Fuchs , Jakob Knollmüller , Jakob Roth , Vincent Eberle , Philipp Frank , Torsten A. Enßlin , Lukas Heinrich

Data from radio interferometers provide a substantial challenge for statisticians. It is incomplete, noise-dominated and originates from a non-trivial measurement process. The signal is not only corrupted by imperfect measurement devices…

Instrumentation and Methods for Astrophysics · Physics 2020-11-11 Philipp Arras , Jakob Knollmüller , Henrik Junklewitz , Torsten A. Enßlin

After several generations of interferometers in radioastronomy, wide-field imaging at high angular resolution is today a major goal for trying to match optical wide-field performances. All the radio-interferometric, wide-field imaging…

Instrumentation and Methods for Astrophysics · Physics 2015-05-18 Jérôme Pety , Nemesio J. Rodriguez-Fernandez

We propose the multi-frequency synthesis (MFS) algorithm with spectral correction of frequency-dependent source brightness distribution based on maximum entropy method. In order to take into account the spectral terms of n-th order in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Anisa T. Bajkova , Alexander B. Pushkarev

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

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

Radio synthesis imaging is dependent upon deconvolution algorithms to counteract the sparse sampling of the Fourier plane. These deconvolution algorithms find an estimate of the true sky brightness from the necessarily incomplete sampled…

Astrophysics · Physics 2009-11-13 T. J. Cornwell

CLEAN, the commonly employed imaging algorithm in radio interferometry, suffers from a number of shortcomings: in its basic version it does not have the concept of diffuse flux, and the common practice of convolving the CLEAN components…

Instrumentation and Methods for Astrophysics · Physics 2021-02-17 Philipp Arras , Hertzog L. Bester , Richard A. Perley , Reimar Leike , Oleg Smirnov , Rüdiger Westermann , Torsten A. Enßlin

The CLEAN algorithm, widely used in radio interferometry for the deconvolution of radio images, performs well only if the raw radio image (dirty image) is, to good approximation, a simple convolution between the instrumental point-spread…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 I. M. Stewart , D. M. Fenech , T. W. B. Muxlow

Sky models have been used in the past to calibrate individual low radio frequency telescopes. Here we generalize this approach from a single antenna to a two element interferometer and formulate the problem in a manner to allow us to…

Instrumentation and Methods for Astrophysics · Physics 2017-06-28 Divya Oberoi , Rohit Sharma , Alan E. E. Rogers

The new technique, multi-frequency imaging (MFI) is developed. In VLBI, Multi-Frequency Imaging (MFI) consists of multi-frequency synthesis (MFS) and multi-frequency analysis (MFA) of the VLBI data obtained from observations on various…

Astrophysics · Physics 2007-05-23 S. Likhachev

High resolution imaging is achieved using increasingly larger apertures and successively shorter wavelengths. Optical aperture synthesis is an important high-resolution imaging technology used in astronomy. Conventional long baseline…

Optical interferometers provide multiple wavelength measurements. In order to fully exploit the spectral and spatial resolution of these instruments, new algorithms for image reconstruction have to be developed. Early attempts to deal with…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Éric Thiébaut , Ferréol Soulez , Loïc Denis

Infrared space interferometers can surpass the spatial resolution limitations of single-dish space telescopes. However, stellar interferometers from space have not been realized because of technical difficulties. Two beams coming from…

Instrumentation and Methods for Astrophysics · Physics 2022-01-20 Taro Matsuo , Satoshi Ikari , Hirotaka Kondo , Sho Ishiwata , Shinichi Nakasuka , Tomoyasu Yamamuro

A new multi-frequency synthesis algorithm for reconstructing images from multi-frequency VLBI data is proposed. The algorithm is based on a generalized maximum-entropy method, and makes it possible to derive an effective spectral correction…

Astrophysics · Physics 2011-08-31 Anisa T. Bajkova
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