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Related papers: CLEAN and multi-scale CLEAN for STIX in Solar Orbi…

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Regularized imaging spectroscopy was introduced for the construction of electron flux images at different energies from count visibilities recorded by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). In this work we seek…

Solar and Stellar Astrophysics · Physics 2023-11-14 Anna Volpara , Paolo Massa , Sam Krucker , A Gordon Emslie , Michele Piana , Anna Maria Massone

The high contrast and spatial resolution requirements for directly imaging exoplanets requires effective coordination of wavefront control, coronagraphy, observation techniques, and post-processing algorithms. However, even with this suite…

Direct detection is a very promising field in exoplanet science. It allows the detection of companions with large separation and allows their spectral analysis. A few planets have already been detected and are under spectral analysis. But…

Instrumentation and Methods for Astrophysics · Physics 2017-10-11 Johan Mazoyer , Raphaël Galicher , Pierre Baudoz , Gérard Rousset

This paper shows that compressed sensing realized by means of regularized deconvolution and the Finite Isotropic Wavelet Transform is effective and reliable in hard X-ray solar imaging. The method utilizes the Finite Isotropic Wavelet…

Solar and Stellar Astrophysics · Physics 2018-07-18 M. A. Duval-Poo , M. Piana , A. M. Massone

Ptychography has become prominent at synchrotron facilities worldwide for characterizing biological and material specimens' topological structures and properties at the nanometer or atomic scale, due to its lens - less, highly quantitative…

Image and Video Processing · Electrical Eng. & Systems 2025-01-28 Tao Liu , Bingyang Wang , JiangTao Zhao , Maik Kahnt , Fucai Zhang

The CERN Axion Solar Telescope (CAST) searches for solar axions employing a 9 Tesla superconducting dipole magnet equipped with 3 independent detection systems for X-rays from axion-photon conversions inside the 10 m long magnetic field.…

Astrophysics · Physics 2007-05-23 R. Kotthaus , H. Braeuninger , P. Friedrich , R. Hartmann , D. Kang , M. Kuster , G. Lutz , L. Strueder

We previously demonstrated near-field speckle scanning based x-ray imaging to be an easy-to-implement phase sensing method capable of providing both high sensitivity and high resolution. Yet, this performance combination could only be…

Medical Physics · Physics 2017-06-21 Sebastien Berujon , Eric Ziegler

The proposed next-generation Very Large Array (ngVLA) will enable the imaging of astronomical sources in unprecedented detail by providing an order of magnitude improvement in sensitivity and angular resolution compared with radio…

Solar and Stellar Astrophysics · Physics 2019-10-23 Kazunori Akiyama , Lynn D. Matthews

Context. Most popular algorithms in use to remove the effects of a telescope's point spread function (PSF) in radio astronomy are variants of the CLEAN algorithm. Most of these algorithms model the sky brightness using the delta-function…

Instrumentation and Methods for Astrophysics · Physics 2017-12-18 L. Zhang , S. Bhatnagar , U. Rau , M. Zhang

Super-resolution microscopes (such as STED) illuminate samples with a tiny spot, and achieve very high resolution. But structures smaller than the spot cannot be resolved in this way. Therefore, we propose a technique to solve this problem.…

Image and Video Processing · Electrical Eng. & Systems 2019-11-20 Yaohua Xie

A long-standing issue in solar ground-based observations has been the contamination of data due to stray light, which is particularly relevant in inversions of spectropolarimetric data. We aim to build on a statistical method of correcting…

Solar and Stellar Astrophysics · Physics 2021-12-07 Sudharshan Saranathan , Michiel van Noort , Sami K. Solanki

Self-calibration methods with the CLEAN algorithm have been widely employed in Very Long Baseline Interferometry (VLBI) data processing in order to correct antenna-based amplitude and phase corruptions present in the data. However, human…

Instrumentation and Methods for Astrophysics · Physics 2024-10-02 Jong-Seo Kim , Aleksei S. Nikonov , Jakob Roth , Torsten A. Ensslin , Michael Janssen , Philipp Arras , Hendrik Mueller , Andrei P. Lobanov

Optical stellar interferometers have demonstrated milli-arcsecond resolution with few apertures spaced hundreds of meters apart. To obtain rich direct images, many apertures will be needed, for a better sampling of the incoming wavefront.…

Instrumentation and Methods for Astrophysics · Physics 2014-09-17 Arun Surya , Swapan K. Saha , Antoine Labeyrie

Solar hard X-ray observations provide diagnostics of the hottest plasmas and of nonthermal electron populations present during solar flares and coronal mass ejections. HXR images of specific energy ranges often contain overlapping…

Solar and Stellar Astrophysics · Physics 2026-01-14 Muriel Zoë Stiefel , Paolo Massa , Alessia Guidetti , Marina Battaglia , Säm Krucker

High-contrast imaging data analysis depends on removing residual starlight from the host star to reveal planets and disks. Most observers do this with principal components analysis (i.e. KLIP) using modes computed from the science images…

Context: Interferometric imaging is algorithmically and computationally challenging as there is no unique inversion from the measurement data back to the sky maps, and the datasets can be very large. Many imaging methods already exist, but…

Instrumentation and Methods for Astrophysics · Physics 2024-10-23 Jakob Roth , Philipp Frank , Hertzog L. Bester , Oleg M. Smirnov , Rüdiger Westermann , Torsten A. Enßlin

Quantitative and analytical analysis of modulation process of the collimator is a great challenge, and is also of great value to the design and development of Fourier transform imaging telescopes. The Hard X-ray Imager (HXI), as one of the…

Instrumentation and Methods for Astrophysics · Physics 2023-02-01 Xian-Kai Jiang , Jian Wu , Deng-Yi Chen , Yi-Ming Hu , Hao-Xiang Wang , Wei Liu , Zhe Zhang

The ever-increasing brightness of synchrotron radiation sources demands improved x-ray optics to utilise their capability for imaging and probing biological cells, nano-devices, and functional matter on the nanometre scale with chemical…

Fourier-based optical computing operations, such as spatial differentiation, have recently been realized in compact form factors using flat optics. Experimental demonstrations, however, have been limited to coherent light requiring laser…

Optics · Physics 2021-12-07 Xiaomeng Zhang , Benfeng Bai , Hong-Bo Sun , Guofan Jin , Jason Valentine

Four NASA Science and Technology Definition Teams have been convened in order to develop and study four mission concepts to be evaluated by the upcoming 2020 Decadal Survey. The Lynx x-ray surveyor mission is one of these four large…

Instrumentation and Methods for Astrophysics · Physics 2019-06-25 Abraham D. Falcone , Ralph P. Kraft , Marshall W. Bautz , Jessica A. Gaskin , John A. Mulqueen , Doug A. Swartz