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Magnetic field couples the solar interior to the solar atmosphere, known as the corona. The coronal magnetic field is one of the crucial parameters which determines the coronal structures and regulates the space weather phenomena like…

Solar and Stellar Astrophysics · Physics 2022-07-26 Devojyoti Kansabanik , Divya Oberoi , Surajit Mondal

The aim of the new generation of radio synthesis arrays such as LOFAR and SKA is to achieve much higher sensitivity, resolution and frequency coverage than what is available now, especially at low frequencies. To accomplish this goal, the…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 S. Kazemi , S. Yatawatta , S. Zaroubi , A. G. de Bruyn , L. V. E. Koopmans , J. Noordam

This paper investigates the problem of direction-of-arrival (DOA) estimation using multiple partially-calibrated sparse subarrays. In particular, we present the Generalized Coarray Multiple Signal Classification (GCA-MUSIC) DOA estimation…

Machine Learning · Computer Science 2024-08-07 W. S. Leite , R. C. de Lamare

We present an imaging algorithm for polarimetric interferometric data from radio telescopes. It is based on Bayesian statistics and thereby able to provide uncertainties and to incorporate prior information such as positivity of the total…

Instrumentation and Methods for Astrophysics · Physics 2025-04-02 Philipp Arras , Jakob Roth , Martin Reinecke , Richard A. Perley , Andrei Frolov , Rüdiger Westermann , Torsten A. Enßlin

Faraday tomography (or rotation measure synthesis) is a procedure to convert linear polarization spectra into the Faraday dispersion function, which provides us with unique information of magneto-ionic media along the line of sight.…

Instrumentation and Methods for Astrophysics · Physics 2018-12-03 Kazunori Akiyama , Takuya Akahori , Yoshimitsu Miyashita , Shinsuke Ideguchi , Ryosuke Yamaguchi , Shiro Ikeda , Keitaro Takahashi

This manual is intended to help ALMA and other interferometer users improve images by recognising limitations and how to overcome them and deciding when and how to use self-calibration. The images provided by the ALMA Science Archive are…

Instrumentation and Methods for Astrophysics · Physics 2022-07-13 A. M. S. Richards , E. Moravec , S. Etoka , E. B. Fomalont , A. F. Pérez-Sánchez , M. C. Toribio , R. A. Laing

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, to realise these goals significant…

Instrumentation and Methods for Astrophysics · Physics 2017-11-20 Luke Pratley , Jason D. McEwen , Mayeul d'Avezac , Rafael E. Carrillo , Alexandru Onose , Yves Wiaux

We present a practical implementation of a phase-coherent mapping technique for pulsar timing arrays that resolves the full complex polarisation state of the gravitational-wave sky as a function of direction and frequency. Unlike standard…

High Energy Astrophysical Phenomena · Physics 2026-04-22 Małgorzata Curyło , Eric Thrane , Paul D. Lasky , Dawson S. Gaynor

Radio interferometry allows astronomers to probe small spatial scales that are often inaccessible with single-dish instruments. However, recovering the radio sky from an interferometer is an ill-posed deconvolution problem that astronomers…

Instrumentation and Methods for Astrophysics · Physics 2022-05-25 Liam Connor , Katherine L. Bouman , Vikram Ravi , Gregg Hallinan

The approaches for analyzing the polarimetric scattering matrix of polarimetric synthetic aperture radar (PolSAR) data have always been the focus of PolSAR image classification. Generally, the polarization coherent matrix and the covariance…

Computer Vision and Pattern Recognition · Computer Science 2019-04-26 Xu Liu , Licheng Jiao , Xu Tang , Qigong Sun , Dan Zhang

Astronomical imaging using aperture synthesis telescopes requires deconvolution of the point spread function as well as calibration of instrumental and atmospheric effects. In general, such effects are time-variable and vary across the…

Astrophysics · Physics 2009-11-13 S. Bhatnagar , T. J. Cornwell , K. Golap , Juan M. Uson

The development of new phased array systems in radio astronomy, as the low frequency array (LOFAR) and the square kilometre array (SKA), formed of a large number of small and flexible elementary antennas, has led to significant challenges.…

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

We present a novel Bayesian model and a corresponding robust, probabilistic calibration procedure for the CORSAIR polarimeter that can be applied to other polarimeters. Our calibration procedure combines existing Mueller matrix…

Solar and Stellar Astrophysics · Physics 2026-05-28 Alan Hsu , Jenna Samra , Steven Tomczyk , Maxim Kramar

We describe a novel method to measure the absolute orientation of the polarization plane of the CMB with arcsecond accuracy, enabling unprecedented measurements for cosmology and fundamental physics. Existing and planned CMB polarization…

Instrumentation and Methods for Astrophysics · Physics 2017-05-26 Federico Nati , Mark J. Devlin , Martina Gerbino , Bradley R. Johnson , Brian Keating , Luca Pagano , Grant Teply

Radio interferometers can measure the full polarization state of incoming waves by cross--correlating all combinations of two orthogonal polarizations at each antenna. The independent sets of electronics used to detect the two polarization…

Instrumentation and Methods for Astrophysics · Physics 2012-05-18 W. D. Cotton

Polarization diversity offers a cost- and space-efficient solution to enhance the performance of integrated sensing and communication systems. Polarimetric sensing exploits the signal's polarity to extract details about the target such as…

Signal Processing · Electrical Eng. & Systems 2026-01-09 Byunghyun Lee , Rang Liu , David J. Love , James V. Krogmeier , A. Lee Swindlehurst

Radio Interferometry is an essential method for astronomical observations. Self-calibration techniques have increased the quality of the radio astronomical observations (and hence the science) by orders of magnitude. Recently, there is a…

Astrophysics · Physics 2008-11-03 Sarod Yatawatta , Saleem Zaroubi , Ger de Bruyn , Leon Koopmans , Jan Noordam

Direction of arrival (DOA) estimation in array processing using uniform/sparse linear arrays is concerned in this paper. While sparse methods via approximate parameter discretization have been popular in the past decade, the discretization…

Information Theory · Computer Science 2014-10-24 Zai Yang , Lihua Xie , Cishen Zhang

In many areas of imaging science, it is difficult to measure the phase of linear measurements. As such, one often wishes to reconstruct a signal from intensity measurements, that is, perform phase retrieval. In several applications the…

Information Theory · Computer Science 2015-06-16 Afonso S. Bandeira , Dustin G. Mixon