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We describe a scalable distributed imaging algorithm framework for next-generation radio telescopes, managing the Fourier transform from apertures to sky (or vice versa) with a focus on minimising memory load, data transfers, and…

Instrumentation and Methods for Astrophysics · Physics 2024-07-17 Peter Wortmann , James Kent , Bojan Nikolic

With the next generation of interferometric telescopes, such as the Square Kilometre Array (SKA), the need for highly computationally efficient reconstruction techniques is particularly acute. The challenge in designing learned, data-driven…

Instrumentation and Methods for Astrophysics · Physics 2025-06-17 Matthijs Mars , Marta M. Betcke , Jason D. McEwen

In this paper, we focus our attention on the following question: How well can we recover the power spectrum of the cosmic microwave background from the maps of a given experiment?. Each experiment is described by a a pixelization scale, a…

Astrophysics · Physics 2016-08-15 D. Sáez , J. V. Arnau

Linear optical networks are fundamental to the advancement of quantum technologies, including quantum computing, communication, and sensing. The accurate characterization of these networks, described by unitary matrices, is crucial to their…

The Haslam 408 MHz all-sky map is widely used as a template to model the diffuse Galactic synchrotron emission at radio and microwave frequencies. Recent studies have suggested that there are large uncorrected flux scale errors in this map,…

Instrumentation and Methods for Astrophysics · Physics 2025-11-26 Ainulnabilah Nasirudin , Philip Bull

The sparse layouts of radio interferometers result in an incomplete sampling of the sky in Fourier space which leads to artifacts in the reconstructed images. Cleaning these systematic effects is essential for the scientific use of…

Instrumentation and Methods for Astrophysics · Physics 2023-07-27 Kevin Schmidt , Felix Geyer , Stefan Fröse , Paul-Simon Blomenkamp , Marcus Brüggen , Francesco de Gasperin , Dominik Elsässer , Wolfgang Rhode

3D image processing constitutes nowadays a challenging topic in many scientific fields such as medicine, computational physics and informatics. Therefore, development of suitable tools that guaranty a best treatment is a necessity.…

Numerical Analysis · Computer Science 2018-05-22 Malika Jallouli , Wafa Bel Hadj Khalifa , Anouar Ben Mabrouk , Mohamed Ali Mahjoub

Given the incomplete sampling of spatial frequencies by radio interferometers, achieving precise restoration of astrophysical information remains challenging. To address this ill-posed problem, compressive sensing(CS) provides a robust…

Instrumentation and Methods for Astrophysics · Physics 2025-05-09 Lei Yu , Bin Liu , Cheng-Jin Jin , Ru-Rong Chen , Hong-Wei Xi , Bo Peng

We derive a compressive sampling method for acoustic field reconstruction using field measurements on a predefined spherical grid that has theoretically guaranteed relations between signal sparsity, measurement number, and reconstruction…

Signal Processing · Electrical Eng. & Systems 2023-07-19 Marc Andrew Valdez , Alex J. Yuffa , Michael B. Wakin

We apply a mass reconstruction technique to simulated large-scale structure gravitational distortion maps, from 2.5' to 10 degree scales, for different cosmological scenarii. The projected mass is reconstructed using a non-parametric least…

Astrophysics · Physics 2007-05-23 L. Van Waerbeke , F. Bernardeau , Y. Mellier

In-flight measurement of the antenna main beams of the Planck instruments is a crucial input to the data analysis pipeline. We study the main beam reconstruction achievable through external planets using a flight simulator to model their…

Astrophysics · Physics 2007-05-23 C. Burigana , P. Natoli , N. Vittorio , N. Mandolesi , M. Bersanelli

I present an exact and explicit solution to the scalar (Stokes flux intensity) radio interferometer imaging equation on a spherical surface which is valid also for non-coplanar interferometer configurations. This imaging equation is…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 T. D. Carozzi

This paper addresses the reconstruction of periodic structures using phase or phaseless near-field measurements. We introduce a novel illumination strategy based on the quasi-periodic condition. Employing the Dirichlet-to-Neumann (DtN) map,…

Mathematical Physics · Physics 2024-04-12 Jue Wang , Yujie Wang , Lei Zhang , Enxi Zheng

To date weak gravitational lensing surveys have typically been restricted to small fields of view, such that the $\textit{flat-sky approximation}$ has been sufficiently satisfied. However, with Stage IV surveys ($\textit{e.g. LSST}$ and…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-19 Matthew A. Price , Jason D. McEwen , L. Pratley , Thomas D. Kitching

We consider the imaging of cosmic strings by using Cosmic Microwave Background (CMB) data. Mathematically, we study the inversion of an X-ray transform in Lorentzian geometry, called the light ray transform. The inverse problem is highly…

Numerical Analysis · Mathematics 2024-05-06 Julianne Chung , Lucas Onisk , Yiran Wang

Observations of the EoR with the 21-cm hyperfine emission of neutral hydrogen (HI) promise to open an entirely new window onto the formation of the first stars, galaxies and accreting black holes. In order to characterize the weak 21-cm…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-06 Abhik Ghosh , L. V. E. Koopmans , Emma Chapman , Vibor Jelic

A method for solving the inverse problem of designing the structure of a one-dimensional photonic crystal is proposed and experimentally implemented. It is known that a one-dimensional photonic crystal with a spatial sinusoidal modulation…

Optics · Physics 2023-08-09 P. S. Emelyantsev , N. I. Pyshkov , S. E. Svyakhovskiy

3D image reconstruction from a set of X-ray projections is an important image reconstruction problem, with applications in medical imaging, industrial inspection and airport security. The innovation of X-ray emitter arrays allows for a…

Medical Physics · Physics 2016-11-23 Maria Klodt , Raphael Hauser

We consider the reconstruction of the shape and the impedance function of an obstacle from measurements of the scattered field at receivers outside the object. The data is assumed to be generated by plane waves impinging on the obstacle…

Numerical Analysis · Mathematics 2021-04-29 Carlos Borges , Manas Rachh

The investigation into the scattering of plane waves by a periodic array of parallel cylinders utilizes the method of cylindrical wave decomposition, thereby reducing the problem complexity to a series of linear algebraic equations. This…

Optics · Physics 2024-06-21 A. S. Bereza , A. E. Chernyavsky , S. V. Perminov , D. A. Shapiro
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