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Related papers: Wavelets and sparsity for Faraday tomography

200 papers

The problem of imaging extended targets (sources or scatterers) is formulated in the framework of compressed sensing with emphasis on subwavelength resolution. The proposed formulation of the problems of inverse source/scattering is…

Optics · Physics 2009-09-15 Albert C. Fannjiang

The special affine Fourier transform (SAFT) is a promising tool for analyzing non-stationary signals with more degrees of freedom. However, the SAFT fails in obtaining the local features of non-transient signals due to its global kernel and…

Functional Analysis · Mathematics 2020-06-11 Firdous A. Shah , Azhar Y. Tantary , Aajaz A. Teali

Interpreting scattered acoustic and electromagnetic wave patterns is a computational task that enables remote imaging in a number of important applications, including medical imaging, geophysical exploration, sonar and radar detection, and…

Computational Physics · Physics 2025-04-03 Owen Melia , Olivia Tsang , Vasileios Charisopoulos , Yuehaw Khoo , Jeremy Hoskins , Rebecca Willett

Sparse-view 3D Gaussian Splatting (3DGS) presents significant challenges in reconstructing high-quality novel views, as it often overfits to the widely-varying high-frequency (HF) details of the sparse training views. While frequency…

Computer Vision and Pattern Recognition · Computer Science 2025-10-09 Hung Nguyen , Runfa Li , An Le , Truong Nguyen

Faraday tomography is thought to be a powerful tool to explore cosmic magnetic field. Broadband radio polarimetric data is essential to ensure the quality of Faraday tomography, but such data is not easy to obtain because of radio frequency…

Instrumentation and Methods for Astrophysics · Physics 2018-12-05 Takuya Akahori , Shinsuke Ideguchi , Takahiro Aoki , Kazuhiro Takefuji , Hideki Ujihara , Keitaro Takahashi

Knowledge about the magnetic fields in supernova remnants (SNRs) is of paramount importance for constraining Galactic cosmic ray acceleration models. It could also indirectly provide information on the interstellar magnetic fields. In this…

High Energy Astrophysical Phenomena · Physics 2022-08-23 Shinsuke Ideguchi , Tsuyoshi Inoue , Takuya Akahori , Keitaro Takahashi

Nonuniform Fourier data are routinely collected in applications such as magnetic resonance imaging, synthetic aperture radar, and synthetic imaging in radio astronomy. To acquire a fast reconstruction that does not require an online inverse…

Numerical Analysis · Mathematics 2016-10-05 Anne Gelb , Guohui Song

Sampling strategies are important for sparse imaging methodologies, especially those employing the discrete Fourier transform (DFT). Chaotic sensing is one such methodology that employs deterministic, fractal sampling in conjunction with…

Image and Video Processing · Electrical Eng. & Systems 2022-05-23 Jacob M. White , Stuart Crozier , Shekhar S. Chandra

To derive the convergence field from the gravitational shear (gamma) of the background galaxy images, the classical methods require a convolution of the shear to be performed over the entire sky, usually expressed thanks to the Fast Fourier…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 E. Deriaz , J. -L. Starck , S. Pires

Recovering a sparse signal from its low-pass projections in the Fourier domain is a problem of broad interest in science and engineering and is commonly referred to as super-resolution. In many cases, however, Fourier domain may not be the…

Information Theory · Computer Science 2019-02-20 Ayush Bhandari , Yonina C. Eldar

The technique of Faraday tomography is a key tool for the study of magnetised plasmas in the new era of broadband radio polarisation observations. In particular, observations at metre-wavelengths provide significantly better Faraday depth…

High Energy Astrophysical Phenomena · Physics 2018-12-03 Shane P. O'Sullivan , M. Brüggen , C. L. Van Eck , M. J. Hardcastle , M. Haverkorn , T. W. Shimwell , C. Tasse , V. Vacca , C. Horellou , G. Heald

In this paper, we study the mathematical imaging problem of diffraction tomography (DT), which is an inverse scattering technique used to find material properties of an object by illuminating it with probing waves and recording the…

Numerical Analysis · Mathematics 2023-05-16 Florian Faucher , Clemens Kirisits , Michael Quellmalz , Otmar Scherzer , Eric Setterqvist

The Faraday dispersion function (FDF), which can be derived from an observed polarization spec- trum by Faraday rotation measure synthesis, is a profile of polarized emissions as a function of Faraday depth. We study intrinsic FDFs along…

Astrophysics of Galaxies · Physics 2015-06-22 Shinsuke Ideguchi , Yuichi Tashiro , Takuya Akahori , Keitaro Takahashi , Dongsu Ryu

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

We introduce a new technique for imaging the polarized radio sky using interferometric data. The new approach, which we call Faraday synthesis, combines aperture and rotation measure synthesis imaging and deconvolution into a single…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 M. R. Bell , T. A. Enßlin

We present a fast iterative FFT-based reconstruction algorithm that allows for non- parallel redshift-space distortions (RSD). We test our algorithm on both N-body dark matter simulations and mock distributions of galaxies designed to…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-17 Angela Burden , Will J. Percival , Cullan Howlett

In this paper, we investigate the extension of the recently proposed weighted Fourier burst accumulation (FBA) method into the wavelet domain. The purpose of FBA is to reconstruct a clean and sharp image from a sequence of blurred frames.…

Computer Vision and Pattern Recognition · Computer Science 2024-10-31 Jerome Gilles , Stanley Osher

This paper is concerned with uniqueness, phase retrieval and shape reconstruction methods for solving inverse electromagnetic source scattering problems with multi-frequency sparse phased or phaseless far field data. With the phased data,…

Analysis of PDEs · Mathematics 2019-06-07 Xia Ji , Xiaodong Liu

Compressed sensing allows for the recovery of sparse signals from few measurements, whose number is proportional to the sparsity of the unknown signal, up to logarithmic factors. The classical theory typically considers either random linear…

Functional Analysis · Mathematics 2025-04-02 Giovanni S. Alberti , Alessandro Felisi , Matteo Santacesaria , S. Ivan Trapasso

Sampling theory in fractional Fourier Transform (FrFT) domain has been studied extensively in the last decades. This interest stems from the ability of the FrFT to generalize the traditional Fourier Transform, broadening the traditional…

Information Theory · Computer Science 2024-04-30 Václav Pavlíček , Ayush Bhandari