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Related papers: Faraday Tomography with Sparse Modeling

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Faraday Rotation-Conversion is the simultaneous rotation of all three Stokes polarization parameters $Q$, $U$, $V$ as an electromagnetic wave propagates through a magnetized plasma. In this regime the Faraday plasma screen is characterized…

High Energy Astrophysical Phenomena · Physics 2019-05-15 Andrei Gruzinov , Yuri Levin

Faraday tomography is a powerful method to diagnose polarizations and Faraday rotations along the line of sight. The quality of Faraday tomography is, however, limited by several conditions. Recently, it is reported that Faraday tomography…

Instrumentation and Methods for Astrophysics · Physics 2014-05-26 Kohei Kumazaki , Takuya Akahori , Shinsuke Ideguchi , Tomoharu Kurayama , Keitaro Takahashi

Compressed sensing theory is slowly making its way to solve more and more astronomical inverse problems. We address here the application of sparse representations, convex optimization and proximal theory to radio interferometric imaging.…

Instrumentation and Methods for Astrophysics · Physics 2015-08-28 Julien N. Girard , Hugh Garsden , Jean Luc Starck , Stéphane Corbel , Arnaud Woiselle , Cyril Tasse , John P. McKean , Jérôme Bobin

Faraday tomography allows us to map diffuse polarized synchrotron emission from our Galaxy and use it to interpret the magnetic field in the interstellar medium (ISM). We have applied Faraday tomography to 60 observations from the LOFAR…

We propose a novel algorithm for image reconstruction in radio interferometry. The ill-posed inverse problem associated with the incomplete Fourier sampling identified by the visibility measurements is regularized by the assumption of…

Instrumentation and Methods for Astrophysics · Physics 2012-10-12 R. E. Carrillo , J. D. McEwen , Y. Wiaux

Interferometric Synthetic Aperture Radar (InSAR) Imaging methods are usually based on algorithms of match-filtering type, without considering the scene's characteristic, which causes limited imaging quality. Besides, post-processing steps…

Signal Processing · Electrical Eng. & Systems 2022-10-07 Xu Zhan , Xiaoling Zhang , Shunjun Wei , Jun Shi

Photoacoustic tomography is a hybrid biomedical technology, which combines the advantages of acoustic and optical imaging. However, for the conventional image reconstruction method, the image quality is affected obviously by artifacts under…

Image and Video Processing · Electrical Eng. & Systems 2024-06-26 Bowei Yao , Yi Zeng , Haizhao Dai , Qing Wu , Youshen Xiao , Fei Gao , Yuyao Zhang , Jingyi Yu , Xiran Cai

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

In a recent article series, the authors have promoted convex optimization algorithms for radio-interferometric imaging in the framework of compressed sensing, which leverages sparsity regularization priors for the associated inverse problem…

Instrumentation and Methods for Astrophysics · Physics 2014-04-01 Rafael E. Carrillo , Jason D. McEwen , Yves Wiaux

Plasma diagnostics often employ computerized tomography to estimate emissivity profiles from a finite, and often limited, number of line-integrated measurements. Decades of algorithmic refinement have brought considerable improvements, and…

Plasma Physics · Physics 2026-03-12 D. Hamm , C. Theiler , M. Simeoni , B. P. Duval , T. Debarre , L. Simons , J. R. Queralt

This paper introduces a sparse projection matrix composed of discrete (digital) periodic lines that create a pseudo-random (p.frac) sampling scheme. Our approach enables random Cartesian sampling whilst employing deterministic and…

Image and Video Processing · Electrical Eng. & Systems 2024-01-09 Marlon Bran Lorenzana , Benjamin Cottier , Matthew Marques , Andrew Kingston , Shekhar S. Chandra

We investigate the reconstruction problem of limited angle tomography. Such problems arise naturally in applications like digital breast tomosynthesis, dental tomography, electron microscopy etc. Since the acquired tomographic data is…

Numerical Analysis · Mathematics 2011-09-05 Jürgen Frikel

We extend the rotation measure work of Burn (1966) to the cases of limited sampling of lambda squared space and non-constant emission spectra. We introduce the rotation measure transfer function (RMTF), which is an excellent predictor of…

Astrophysics · Physics 2009-11-13 M. A. Brentjens , A. G. de Bruyn

Diffraction tomography is a widely used inverse scattering technique for quantitative imaging of weakly scattering media. In its conventional formulation, diffraction tomography assumes monochromatic plane wave illumination. This…

Numerical Analysis · Mathematics 2026-03-11 Peter Elbau , Noemi Naujoks , Otmar Scherzer

We develop a novel algorithm for sparse Stokes parameters imaging in radio interferometry under the polarization constraint. The latter is a physical non-linear relation between the Stokes parameters, imposing that the polarization…

Instrumentation and Methods for Astrophysics · Physics 2018-07-18 Jasleen Birdi , Audrey Repetti , Yves Wiaux

Observations of synchrotron polarization at multiple frequencies in the presence of Faraday rotation can provide a way to reconstruct the 3D magnetic field distribution. In this paper we compare the well known Faraday Tomography (FT, Burn…

Astrophysics of Galaxies · Physics 2020-01-08 Ka Wai Ho , Ka Ho Yuen , Po Kin Leung , A. Lazarian

Faraday rotation measure (RM) synthesis is a well-known approach originated in Burn (1966) and later developed by Brentjens \& de Bruyn (2005) for studying magnetic fields. This work presents a complementary approach--the polarization…

High Energy Astrophysical Phenomena · Physics 2025-08-22 Yawen Xiao , Jianfu Zhang , Alex Lazarian , Dmitri Pogosyan

X-ray tomography is a reliable tool for determining the inner structure of 3D object with penetrating X-rays. However, traditional reconstruction methods such as FDK require dense angular sampling in the data acquisition phase leading to…

Faraday complexity describes whether a spectropolarimetric observation has simple or complex magnetic structure. Quickly determining the Faraday complexity of a spectropolarimetric observation is important for processing large, polarised…

Instrumentation and Methods for Astrophysics · Physics 2021-07-01 M. J. Alger , J. D. Livingston , N. M. McClure-Griffiths , J. L. Nabaglo , O. I. Wong , C. S. Ong

The Galactic Faraday depth sky is a tracer for both the Galactic magnetic field and the thermal electron distribution. It has been previously reconstructed from polarimetric measurements of extra-galactic point sources. Here, we improve on…

Astrophysics of Galaxies · Physics 2020-01-29 Sebastian Hutschenreuter , Torsten A. Enßlin