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Related papers: Three dimensional Doppler tomography

200 papers

X-ray tomography is a powerful volumetric imaging technique, but detailed three dimensional (3D) imaging requires the acquisition of a large number of individual X-ray images, which is time consuming. For applications where spatial…

Image and Video Processing · Electrical Eng. & Systems 2023-02-28 Zhenduo Shang , Thomas Blumensath

Doppler reflectometry is considered in slab plasma model in the frameworks of analytical theory. The diagnostics locality is analyzed for both regimes: linear and nonlinear in turbulence amplitude. The toroidal antenna focusing of probing…

Plasma Physics · Physics 2007-05-23 Evgeniy Gusakov , Alexander Surkov

We consider the problem of elastic diffraction tomography, which consists in reconstructing elastic properties (i.e. mass density and elastic Lam\'e parameters) of a weakly scattering medium from full-field data of scattered waves outside…

Analysis of PDEs · Mathematics 2022-12-07 Bochra Mejri , Otmar Scherzer

Speckle Imaging based on triple correlation is a very efficient image reconstruction technique which is used to retrieve Fourier phase information of the object in presence of atmospheric turbulence. We have developed both Direct Bispectrum…

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

Stellar Doppler velocimetry determines a star's radial velocity $v_r$ via measurement of a redshift, $z$. At precisions below 10 m s$^{-1}$ conversion between the two quantities is complex, and care must be taken to properly account for the…

Instrumentation and Methods for Astrophysics · Physics 2019-01-14 Jason T. Wright

The precise radial velocity technique is a cornerstone of exoplanetary astronomy. Astronomers measure Doppler shifts in the star's spectral features, which track the line-of/sight gravitational accelerations of a star caused by the planets…

Earth and Planetary Astrophysics · Physics 2019-02-06 Jason T. Wright

Spectral Doppler ultrasound imaging allows visualizing blood flow by estimating its velocity distribution over time. Duplex ultrasound is a modality in which an ultrasound system is used for displaying simultaneously both B-mode images and…

Information Theory · Computer Science 2018-08-03 Regev Cohen , Yonina C. Eldar

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 main idea and procedure are presented for a new synthetical method on constraining 3-D structure of emission regions of pulsars. With this method the emission regions can be synthetically constrained by fitting multi-wavelength…

Astrophysics · Physics 2007-05-23 H. G. Wang , H. Zhang , X. H. Cui , G. J. Qiao , K. J. Lee , Y. Liu , R. X. Xu

Eclipsing binaries are vital for directly determining stellar parameters without reliance on models or scaling relations. Spectroscopically derived parameters of detached and semi-detached binaries allow us to determine component masses…

Solar and Stellar Astrophysics · Physics 2017-11-15 Rachel A. Matson , Douglas R. Gies , Zhao Guo , Stephen J. Williams

High-resolution Doppler spectroscopy provides an avenue to study the atmosphere of both transiting and non-transiting planets. This powerful method has also yielded some of the most robust atmospheric detections to date. Currently,…

Earth and Planetary Astrophysics · Physics 2024-04-09 S. M. Matthews , C. A. Watson , E. J. W. de Mooij , T. R. Marsh , M. Brogi , S. R. Merritt , K. W. Smith , D. Steeghs

In this paper, we present an algorithm for determining a curve on the earth's terrain on which a stationary emitter must lie according to a single Doppler shift measured on an unmanned aerial vehicle (UAV) or a low earth orbit satellite…

Signal Processing · Electrical Eng. & Systems 2019-03-13 Qingchen Liu , Samuel P. Drake , Brian D. O. Anderson

Optical diffraction tomography (ODT) is a tomographic technique that can be used to measure the three-dimensional (3D) refractive index distribution within living cells without the requirement of any marker. In principle, ODT can be…

Quantitative Methods · Quantitative Biology 2018-01-03 Paul Müller , Mirjam Schürmann , Chii J. Chan , Jochen Guck

Within the framework of the density matrix theory for the generation and transfer of polarized radiation, velocity density matrix correlations represent an important physical aspect that, however, is often neglected in practical…

Solar and Stellar Astrophysics · Physics 2015-06-15 L. Belluzzi , E. Landi Degl'Innocenti , J. Trujillo Bueno

It is difficult to discover pulsars via their gamma-ray emission because current instruments typically detect fewer than one photon per million rotations. This creates a significant computing challenge for isolated pulsars, where the…

High Energy Astrophysical Phenomena · Physics 2020-10-23 L. Nieder , B. Allen , C. J. Clark , H. J. Pletsch

We present a direct method for isolating the component of the starlight blocked by a planet as it transits its host star, and apply it to spectra of the bright transiting planet HD 189733b. We model the global shape of the stellar…

Solar and Stellar Astrophysics · Physics 2015-05-14 A. Collier Cameron , V. A. Bruce , G. R. M. Miller , A. H. M. J. Triaud , D. Queloz

Doppler imaging (DI) is a powerful spectroscopic inversion technique that enables conversion of a line profile time series into a two-dimensional map of the stellar surface inhomogeneities. In this paper we investigate the accuracy of…

Solar and Stellar Astrophysics · Physics 2016-12-28 O. Kochukhov

Binarity is often invoked to explain peculiarities that can not be explained by the standard theory of stellar evolution. Detecting orbital motion via the Doppler effect is the best method to test binarity when direct imaging is not…

Solar and Stellar Astrophysics · Physics 2014-03-11 N. Gorlova , H. Van Winckel , J. Vos , R. H. Ostensen , A. Jorissen , S. Van Eck , N. Ikonnikova

Doppler Imaging (DI) is a well-established technique to map a physical field at a stellar surface from a time series of high-resolution spectra. In this proof-of-concept study, we aim to show that traditional DI algorithms, originally…

In this work, we propose a novel method to classify close binary stars, derived from the dynamical structure inherent in their light curves. We apply the technique to light curves of binaries from the revised Kepler Eclipsing binary…

Solar and Stellar Astrophysics · Physics 2025-06-05 Anisha R. V. Kashyap , D. Pawar , R. Misra , G. Ambika , Sandip V George