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Related papers: Zeeman-Doppler Imaging : Old Problems and New Meth…

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Extended formulation of Full Waveform Inversion (FWI), called Wavefield Reconstruction Inversion (WRI), offers potential benefits of decreasing the nonlinearity of the inverse problem by replacing the explicit inverse of the ill-conditioned…

Optimization and Control · Mathematics 2020-05-18 Hossein S. Aghamiry , Ali Gholami , Stéphane Operto

In this paper, we address an alternative formulation for the exact inverse formula of the Radon transform on circle arcs arising in a modality of Compton Scattering Tomography in translational geometry proposed by Webber and Miller (Inverse…

Numerical Analysis · Mathematics 2021-12-06 Cécilia Tarpau , Javier Cebeiro , Geneviève Rollet , Mai K. Nguyen , Laurent Dumas

The magnetic inversion method is one of the non-destructive geophysical methods, which aims to estimate the subsurface susceptibility distribution from surface magnetic anomaly data. Recently, supervised deep learning methods have been…

Geophysics · Physics 2023-08-24 Yinshuo Li , Zhuo Jia , Wenkai Lu , Cao Song

PET image reconstruction is challenging due to the ill-poseness of the inverse problem and limited number of detected photons. Recently deep neural networks have been widely and successfully used in computer vision tasks and attracted…

Computer Vision and Pattern Recognition · Computer Science 2017-10-11 Kuang Gong , Jiahui Guan , Kyungsang Kim , Xuezhu Zhang , Georges El Fakhri , Jinyi Qi , Quanzheng Li

The non-uniform surface temperature distribution of rotating active stars is routinely mapped with the Doppler Imaging technique. Inhomogeneities in the surface produce features in high-resolution spectroscopic observations that shift in…

Instrumentation and Methods for Astrophysics · Physics 2022-02-23 A. Asensio Ramos , C. Diaz Baso , O. Kochukhov

We use the POLARIS radiative transport code to generate predictions of the two main observables directly sensitive to the magnetic field morphology and strength in filaments: dust polarization and gas Zeeman line splitting. We simulate…

Astrophysics of Galaxies · Physics 2018-09-19 Stefan Reissl , Amelia M. Stutz , Robert Brauer , Eric W. Pellegrini , Dominik R. G. Schleicher , Ralf Klessen

Magnetic Particle Imaging (MPI) is a recent imaging modality where superparamagnetic nanoparticles are employed as tracers. The reconstruction task is to obtain the spatial particle distribution from a voltage signal induced by the…

Numerical Analysis · Mathematics 2025-08-11 Thomas März , Vladyslav Gapyak , Andreas Weinmann

Reconstructing an image from its Radon transform is a fundamental computed tomography (CT) task arising in applications such as X-ray scans. In many practical scenarios, a full 180-degree scan is not feasible, or there is a desire to reduce…

Computer Vision and Pattern Recognition · Computer Science 2025-02-20 Ilmari Vahteristo , Zhi-Song Liu , Andreas Rupp

This paper presents an uncalibrated deep neural network framework for the photometric stereo problem. For training models to solve the problem, existing neural network-based methods either require exact light directions or ground-truth…

Computer Vision and Pattern Recognition · Computer Science 2021-04-20 Berk Kaya , Suryansh Kumar , Carlos Oliveira , Vittorio Ferrari , Luc Van Gool

The modeling of complex atomic spectra is a difficult task, due to the huge number of levels and lines involved. In the presence of a magnetic field, the computation becomes even more difficult. The anomalous Zeeman pattern is a…

Atomic Physics · Physics 2015-06-04 Jean-Christophe Pain , Franck Gilleron

Recent advances in spectropolarimetry have allowed the reconstruction of stellar coronal magnetic fields. This uses Zeeman-Doppler magnetograms of the surface magnetic field as a lower boundary condition. The ZDI maps, however, suffer from…

Solar and Stellar Astrophysics · Physics 2015-05-18 Colin Johnstone , Moira Jardine , Duncan Mackay

This paper is concerned with the inverse problem of reconstructing small and local perturbations of a planar surface using the field interaction between a known plasmonic particle and the planar surface. The aim is to perform a…

Analysis of PDEs · Mathematics 2018-11-21 Habib Ammari , Doo Sung Choi , Sanghyeon Yu

We present two efficient numerical methods for susceptibility artifact correction applicable in Echo Planar Imaging (EPI), an ultra fast Magnetic Resonance Imaging (MRI) technique widely used in clinical applications. Both methods address a…

Optimization and Control · Mathematics 2016-11-23 Jan Macdonald , Lars Ruthotto

We introduce a novel framework for solving inverse problems using NeRF-style generative models. We are interested in the problem of 3-D scene reconstruction given a single 2-D image and known camera parameters. We show that naively…

Computer Vision and Pattern Recognition · Computer Science 2021-12-17 Giannis Daras , Wen-Sheng Chu , Abhishek Kumar , Dmitry Lagun , Alexandros G. Dimakis

Inverse problems are fundamental in fields like medical imaging, geophysics, and computerized tomography, aiming to recover unknown quantities from observed data. However, these problems often lack stability due to noise and…

Numerical Analysis · Mathematics 2024-06-26 Andrea Ebner , Matthias Schwab , Markus Haltmeier

In image reconstruction there are techniques that use analytical formulae for the Radon transform to recover an image from a continuum of data. In practice, however, one has only discrete data available. Thus one often resorts to sampling…

Functional Analysis · Mathematics 2011-08-30 Isaac Pesenson , Eric Grinberg

In this paper, we address the inverse problem of fast, stable, and high-quality wavefront reconstruction from pyramid wavefront sensor data for Adaptive Optics systems on Extremely Large Telescopes. For solving the indicated problem we…

Instrumentation and Methods for Astrophysics · Physics 2019-05-01 Victoria Hutterer , Ronny Ramlau , Iuliia Shatokhina

Neural fields or implicit neural representations (INRs) have attracted significant attention in computer vision and imaging due to their efficient coordinate-based representation of images and 3D volumes. In this work, we introduce a…

Computer Vision and Pattern Recognition · Computer Science 2024-12-24 AmirEhsan Khorashadizadeh , Tobías I. Liaudat , Tianlin Liu , Jason D. McEwen , Ivan Dokmanić

In this paper I will discuss new magnetic field diagnostics and instrumentation for an area of astrophysics where magnetic field observations have been difficult - circumstellar material. Such diagnostics would be particularly relevant to…

Astrophysics · Physics 2007-05-23 K. H. Nordsieck

Image reconstruction under multiple light scattering is crucial in a number of applications such as diffraction tomography. The reconstruction problem is often formulated as a nonconvex optimization, where a nonlinear measurement model is…

Computer Vision and Pattern Recognition · Computer Science 2018-07-04 Yu Sun , Zhihao Xia , Ulugbek S. Kamilov