English
Related papers

Related papers: Measuring angular diameters of extended sources

200 papers

This paper addresses a factorization method for imaging the support of a wave-number-dependent source function from multi-frequency data measured at a finite pair of symmetric receivers in opposite directions. The source function is given…

Numerical Analysis · Mathematics 2024-01-17 Hongxia Guo , Guanghui Hu , Guanqiu Ma

Precise modeling of extended sources is a central challenge in modern optical engineering, laser physics, and computational lithography. Unlike ideal point sources or completely incoherent thermal radiation sources, real-world light sources…

Optics · Physics 2025-12-09 Rongqi Shang , Donglin Ma

Optimal extraction of cosmological information from observations of the Cosmic Microwave Background critically relies on our ability to accurately undo the distortions caused by weak gravitational lensing. In this work, we demonstrate the…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-07 Thomas Flöss , William R. Coulton , Adriaan J. Duivenvoorden , Francisco Villaescusa-Navarro , Benjamin D. Wandelt

Optical interference is not only a fundamental phenomenon that has enabled new theories of light to be derived but it has also been used in interferometry for the measurement of small displacements, refractive index changes and surface…

Optics · Physics 2021-10-28 Chen Yang , Zhi-Yuan Zhou , Yan Li , Shi-Kai Liu , Zheng Ge , Guang-Can Guo , Bao-Sen Shi

We present an effective and efficient method that explores the properties of Transformers in the frequency domain for high-quality image deblurring. Our method is motivated by the convolution theorem that the correlation or convolution of…

Computer Vision and Pattern Recognition · Computer Science 2022-11-23 Lingshun Kong , Jiangxin Dong , Mingqiang Li , Jianjun Ge , Jinshan Pan

We present a novel, general-purpose method for deconvolving and denoising images from gridded radio interferometric visibilities using Bayesian inference based on a Gaussian process model. The method automatically takes into account…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 P. M. Sutter , Benjamin D. Wandelt , Jason D. McEwen , Emory F. Bunn , Ata Karakci , Andrei Korotkov , Peter Timbie , Gregory S. Tucker , Le Zhang

We are concerned with an inverse problem associated with the fractional Helmholtz system that arises from the study of viscoacoustics in geophysics and thermoviscous modelling of lossy media. We are particularly interested in the case that…

Analysis of PDEs · Mathematics 2018-03-28 Xinlin Cao , Hongyu Liu

A computer code is described for the simulation of gravitational lensing data. The code incorporates adaptive mesh refinement in choosing which rays to shoot based on the requirements of the source size, location and surface brightness…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-29 R. Benton Metcalf , Margarita Petkova

We show that the use of the electromagnetic inverse source framework offers great flexibility in the design of metasurfaces. In particular, this approach is advantageous for antenna design applications where the goal is often to satisfy a…

Applied Physics · Physics 2019-10-17 Trevor Brown , Chaitanya Narendra , Yousef Vahabzadeh , Christophe Caloz , Puyan Mojabi

In medical research, often, genomic or proteomic data are collected, with measurements frequently subject to uncertainties or errors, making it crucial to accurately separate the signals of the genes or proteins, respectively, from the…

Methodology · Statistics 2025-06-03 Akin Anarat , Jean Krutmann , Holger Schwender

For over a century diffraction theory has been thought to limit the resolution of focusing and imaging in the optical domain. The size of the smallest spot achievable is inversely proportional to the range of spatial wavevectors available.…

Optics · Physics 2011-01-11 Michael Mazilu , Joerg Baumgartl , Kishan Dholakia

Many applications seek to measure a sample's absorption coefficient spectrum to retrieve the chemical makeup. Many real world samples are optically turbid, causing scattering confounds which many commercial spectrometers cannot address.…

Optics · Physics 2023-01-05 Giles Blaney , Angelo Sassaroli , Sergio Fantini

Skymaps measured with imaging atmospheric Cherenkov telescopes (IACTs) represent the real source distribution convolved with the point spread function of the observing instrument. Current IACTs have an angular resolution in the order of…

Instrumentation and Methods for Astrophysics · Physics 2015-08-26 Susanne Raab , Ira Jung-Richardt

We study an inverse problem for the wave equation where localized wave sources in random scattering media are to be determined from time resolved measurements of the waves at an array of receivers. The sources are far from the array, so the…

Mathematical Physics · Physics 2016-07-18 Liliana Borcea , Ilker Kocyigit

Modern geometric measure theory, developed largely to solve the Plateau problem, has generated a great deal of technical machinery which is unfortunately regarded as inaccessible by outsiders. Some of its tools (e.g., flat norm distance and…

Differential Geometry · Mathematics 2014-08-27 Sharif Ibrahim

Removing the aberrations introduced by the Point Spread Function (PSF) is a fundamental aspect of astronomical image processing. The presence of noise in observed images makes deconvolution a nontrivial task that necessitates the use of…

Instrumentation and Methods for Astrophysics · Physics 2017-05-03 Samuel Farrens , Jean-Luc Starck , Fred Maurice Ngolè Mboula

We seek to find a shapelet-based scheme for deconvolving galaxy images from the PSF which leads to unbiased shear measurements. Based on the analytic formulation of convolution in shapelet space, we construct a procedure to recover the…

Astrophysics · Physics 2015-03-03 Peter Melchior , Rene Andrae , Matteo Maturi , Matthias Bartelmann

We present methods to rigorously extract parameter combinations that are constrained by data from posterior distributions. The standard approach uses linear methods that apply to Gaussian distributions. We show the limitations of the linear…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-06 Tara Dacunha , Marco Raveri , Minsu Park , Cyrille Doux , Bhuvnesh Jain

A Bayesian method application to the deconvolution of EXAFS spectra is considered. It is shown that for purposes of EXAFS spectroscopy, from the infinitely large number of Bayesian solutions it is possible to determine an optimal range of…

Data Analysis, Statistics and Probability · Physics 2009-11-07 K. V. Klementev

We investigate through dedicated numerical simulations the evolution of the soft X-ray absorption properties of a cloud surrounding a gamma-ray burst source. We show that the absorption properties of the material are strongly modified by…

Astrophysics · Physics 2009-11-07 Davide Lazzati , Rosalba Perna