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We propose a new technique for weak gravitational lensing in the radio band making use of polarization information. Since the orientation of a galaxy's polarized emission is both unaffected by lensing and is related to the galaxy's…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Michael L. Brown , Richard A. Battye

Large-scale astronomical surveys can capture numerous images of celestial objects, including galaxies and nebulae. Analysing and processing these images can reveal intricate internal structures of these objects, allowing researchers to…

Instrumentation and Methods for Astrophysics · Physics 2023-11-02 Peng Jia , Jiameng Lv , Runyu Ning , Yu Song , Nan Li , Kaifan Ji , Chenzhou Cui , Shanshan Li

Modern dual-polarization receivers allow a radio telescope to characterize the full polarization state of incoming insterstellar radio waves. Many astronomers incorrectly consider a polarimeter to be the "backend" of the telescope. We go to…

Instrumentation and Methods for Astrophysics · Physics 2021-10-13 Timothy Robishaw , Carl Heiles

The volume of radio-astronomical data is a considerable burden in the processing and storing of radio observations with high time and frequency resolutions and large bandwidths. Lossy compression of interferometric radio-astronomical data…

Instrumentation and Methods for Astrophysics · Physics 2016-11-09 A. R. Offringa

Radio astronomical observations have very poor signal to noise ratios, unlike in other disciplines. On the other hand, it is possible to observe the object of interest for long time intervals as well as using a wider bandwidth.…

Astrophysics · Physics 2008-09-02 Sarod Yatawatta

Optical interferometric image reconstruction is a challenging, ill-posed optimization problem which usually relies on heavy regularization for convergence. Conventional algorithms regularize in the pixel domain, without cognizance of…

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

A new phase-coherent technique for the calibration of polarimetric data is presented. Similar to the one-dimensional form of convolution, data are multiplied by the response function in the frequency domain. Therefore, the system response…

Astrophysics · Physics 2009-11-07 W. van Straten

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…

Since the birth of X-ray astronomy, spectral, spatial and timing observation improved dramatically, procuring a wealth of information on the majority of the classes of the celestial sources. Polarimetry, instead, remained basically…

Next generation radio interferometric telescopes are entering an era of big data with extremely large data sets. While these telescopes can observe the sky in higher sensitivity and resolution than before, computational challenges in image…

Instrumentation and Methods for Astrophysics · Physics 2019-12-17 Luke Pratley , Jason D. McEwen , Mayeul d'Avezac , Xiaohao Cai , David Perez-Suarez , Ilektra Christidi , Roland Guichard

New generation of radio interferometers are envisaged to produce high quality, high dynamic range Stokes images of the observed sky from the corresponding under-sampled Fourier domain measurements. In practice, these measurements are…

Instrumentation and Methods for Astrophysics · Physics 2020-01-08 Jasleen Birdi , Audrey Repetti , Yves Wiaux

Accurately modeling how real-world materials reflect light remains a core challenge in inverse rendering, largely due to the scarcity of real measured reflectance data. Existing approaches rely heavily on synthetic datasets with simplified…

Computer Vision and Pattern Recognition · Computer Science 2026-03-27 Jing Yang , Krithika Dharanikota , Emily Jia , Haiwei Chen , Yajie Zhao

The shapelets method for image analysis is based upon the decomposition of localised objects into a series of orthogonal components with convenient mathematical properties. We extend the "Cartesian shapelet" formalism from earlier work, and…

Astrophysics · Physics 2009-11-10 Richard Massey , Alexandre Refregier

Imaging polarimetry is a powerful tool for detecting and characterizing exoplanets and circumstellar environments. Polarimetry allows a separation of the light coming from an unpolarized source such as a star and the polarized source such…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 H. Canovas , M. Rodenhuis , S. V. Jeffers , M. Min , C. U. Keller

The challenge of image-based 3D reconstruction for glossy objects lies in separating diffuse and specular components on glossy surfaces from captured images, a task complicated by the ambiguity in discerning lighting conditions and material…

Computer Vision and Pattern Recognition · Computer Science 2025-04-10 Bojian Wu , Yifan Peng , Ruizhen Hu , Xiaowei Zhou

The topology and dynamics of the solar chromosphere are greatly affected by the presence of magnetic fields. The magnetic field can be inferred by analyzing polarimetric observations of spectral lines. Polarimetric signals induced by…

Solar and Stellar Astrophysics · Physics 2019-09-11 C. J. Díaz Baso , J. de la Cruz Rodríguez , S. Danilovic

Polarization measurements done using Imaging Polarimeters such as the Robotic Polarimeter are very sensitive to the presence of artefacts in images. Artefacts can range from internal reflections in a telescope to satellite trails that could…

We consider a method for obtaining information on polarization of astronomical objects radiation at diffraction limited resolution - differential speckle polarimetry. As an observable we propose to use averaged cross spectrum of two…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Boris Safonov

We demonstrate through numerical simulations with real data the feasibility of using compressive sensing techniques for the acquisition of spectro-polarimetric data. This allows us to combine the measurement and the compression process into…

Instrumentation and Methods for Astrophysics · Physics 2015-05-14 A. Asensio Ramos , A. Lopez Ariste