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Related papers: Polca SARA - Full polarization, direction-dependen…

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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

Radio interferometric imaging aims to estimate an unknown sky intensity image from degraded observations, acquired through an antenna array. In the theoretical case of a perfectly calibrated array, it has been shown that solving the…

Instrumentation and Methods for Astrophysics · Physics 2017-07-25 Audrey Repetti , Jasleen Birdi , Arwa Dabbech , Yves Wiaux

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

In recent works, sparse models and convex optimization techniques have been applied to radio-interferometric (RI) imaging showing the potential to outperform state-of-the-art imaging algorithms in the field. In this talk, I will review our…

Instrumentation and Methods for Astrophysics · Physics 2015-02-19 Rafael E. Carrillo , Jason D. McEwen , Yves Wiaux

The calibration of modern radio interferometers is a significant challenge, specifically at low frequencies. In this perspective, we propose a novel iterative calibration algorithm, which employs the popular sparse representation framework,…

Instrumentation and Methods for Astrophysics · Physics 2016-06-06 Martin Brossard , Mohamed Nabil El Korso , Marius Pesavento , Rémy Boyer , Pascal Larzabal

We propose a new technique for radio interferometry to obtain super-resolution full polarization images in all four Stokes parameters using sparse modeling. The proposed technique reconstructs the image in each Stokes parameter from the…

Coronal magnetic fields are well known to be one of the crucial parameters defining coronal physics and space weather. However, measuring the global coronal magnetic fields remains challenging. The polarization properties of coronal radio…

Solar and Stellar Astrophysics · Physics 2022-07-01 Devojyoti Kansabanik , Divya Oberoi , Surajit Mondal

Calibration of instrumental polarization is critical for measuring polarized radio emissions from astrophysical sources to extract the magnetic field information in astrophysical, heliospheric, and terrestrial plasmas. At meter wavelengths,…

Instrumentation and Methods for Astrophysics · Physics 2025-05-08 Devojyoti Kansabanik , Angelos Vourlidas , Soham Dey , Surajit Mondal , Divya Oberoi

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

Imaging polarimetry is an important tool for the study of cosmic magnetic fields. In our Galaxy, polarization levels of a few up to $\sim$10\% are measured in the submillimeter dust emission from molecular clouds and in the synchrotron…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Helmut Wiesemeyer , Talayeh Hezareh , Ernst Kreysa , Axel Weiss , Rolf Güsten , Karl M. Menten , Giorgio Siringo , Frederic Schuller , Attila Kovacs

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

In recent years, handheld and portable terahertz instruments have been in rapid development for various applications ranging from non-destructive testing to biomedical imaging and sensing. For instance, we have deployed our Portable…

Optics · Physics 2024-03-22 Zachery B. Harris , Kuangyi Xu , M. Hassan Arbab

Direction-dependent instrumental polarisation introduces wide-field polarimetric aberrations and limits the dynamic range of low-frequency interferometric images. We therefore provide a detailed two-dimensional analysis of the Giant…

Instrumentation and Methods for Astrophysics · Physics 2014-07-03 J. S. Farnes

A polarimetric synthetic aperture radar (PolSAR) system, which uses multiple images acquired with different polarizations in both transmission and reception, has the potential to improve the description and interpretation of the observed…

Signal Processing · Electrical Eng. & Systems 2025-07-08 Dehbia Hanis , Luca Pallotta , Augusto Aubry , Aichouche Belhadj-Aissa , Antonio De Maio

Context. The current algorithms used for the calibration and analysis of very long baseline interferometry (VLBI) networks that only use linear polarizers (as is the case of the VLBI Global Observing System, VGOS) do not properly account…

Instrumentation and Methods for Astrophysics · Physics 2024-06-19 V. Pérez-Díez , I. Martí-Vidal , E. Albentosa-Ruiz , J. González-García , F. Jaron , T. Savolainen , M. H. Xu , R. Bachiller

In order to meet the theoretically achievable imaging performance, calibration of modern radio interferometers is a mandatory challenge, especially at low frequencies. In this perspective, we propose a novel parallel iterative…

Instrumentation and Methods for Astrophysics · Physics 2016-09-09 Martin Brossard , Mohammed Nabil El Korso , Marius Pesavento , Rémy Boyer , Pascal Larzabal , Stefan J. Wijnholds

Current mm/submm interferometers, like the Atacama Large mm/submm Array (ALMA), use receivers that register the sky signal in a linear polarization basis. In the case of observations performed in full-polarization mode (where the…

Instrumentation and Methods for Astrophysics · Physics 2016-09-21 I. Marti-Vidal , W. H. T. Vlemmings , S. Muller

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

Spectro-polarimetric imaging provides multidimensional optical information acquisition capabilities, offering significant potential for diverse applications. Current spectro-polarimetric imaging systems typically suffer from large physical…

Image and Video Processing · Electrical Eng. & Systems 2025-09-18 Jingyue Ma , Zhenming Yu , Zhengyang Li , Liang Lin , Liming Cheng , Jiayu Di , Tongshuo Zhang , Ning Zhan , Kun Xu

POLSAR image has an advantage over optical image because it can be acquired independently of cloud cover and solar illumination. PolSAR image classification is a hot and valuable topic for the interpretation of POLSAR image. In this paper,…

Computer Vision and Pattern Recognition · Computer Science 2019-06-19 Xu Liu , Licheng Jiao , Dan Zhang , Fang Liu
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