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An autoencoder is used to compress and then reconstruct three-dimensional stratified turbulence data in order to better understand fluid dynamics by studying the errors in the reconstruction. The original single data set is resolved on…

Fluid Dynamics · Physics 2019-07-29 S. M. de Bruyn Kops , D. J. Saunders , E. A. Rietman , G. D. Portwood

The use of instruments that record narrow band images at selected wavelengths is a common approach in solar observations. They allow the scanning of a spectral line by sampling the Stokes profiles with 2D images at each line position, but…

Solar and Stellar Astrophysics · Physics 2018-06-20 T. Felipe , H. Socas-Navarro , D. Przybylski

This study uses plasma-profile data from the EUROfusion pedestal database, focusing on the electron-temperature and electron-density profiles in the edge region of H-mode ELMy JET ITER-Like-Wall (ILW) pulses. We make systematic predictions…

Imaging at a long distance often requires advanced image restoration algorithms to compensate for the distortions caused by atmospheric turbulence. However, unlike many standard restoration problems such as deconvolution, the forward image…

Image and Video Processing · Electrical Eng. & Systems 2022-09-14 Stanley H. Chan

We present the development, tests and first results of the second generation Low Layer Scidar (LOLAS-2). This instrument constitutes a strongly improved version of the prototype Low Layer Scidar, which is aimed at the measurement of optical…

Instrumentation and Methods for Astrophysics · Physics 2016-06-17 R. Avila , C. A. Zuniga , J. J. Tapia-Rodriguez , L. J. Sanchez , I. Cruz-Gonzalez , J. L. Aviles , O. Valdes-Hernandez , E. Carrasco

The reconstruction of ocean subsurface temperature (OST) using satellite remote sensing data holds significant scientific value for advancing the understanding of ocean dynamics and climate variability. However, the scarcity of subsurface…

Atmospheric and Oceanic Physics · Physics 2026-05-05 Ming Shan Loo , Wengen Li , Xudong Jiang , Hailiang Cheng , Zhifei Zhang , Jihong Guan , Yichao Zhang

Turbulence mitigation (TM) aims to remove the stochastic distortions and blurs introduced by atmospheric turbulence into frame cameras. Existing state-of-the-art deep-learning TM methods extract turbulence cues from multiple degraded frames…

Computer Vision and Pattern Recognition · Computer Science 2025-09-05 Huanan Li , Rui Fan , Juntao Guan , Weidong Hao , Lai Rui , Tong Wu , Yikai Wang , Lin Gu

An important issue in the tomographic reconstruction of the solar poles is the relatively rapid evolution of the polar plumes. We demonstrate that it is possible to take into account this temporal evolution in the reconstruction. The…

Astrophysics · Physics 2009-11-13 Nicolas Barbey , Frédéric Auchère , Thomas Rodet , Jean-Claude Vial

The Earth's turbulent atmosphere results in speckled and blurred images of astronomical objects when observed by ground based visible and near-infrared telescopes. Adaptive optics (AO) systems are employed to reduce these atmospheric…

Instrumentation and Methods for Astrophysics · Physics 2022-11-30 Daniel M. Levinstein , Saavidra Perera , Quinn M. Konopacky , Alex Madurowicz , Bruce Macintosh , Lisa Poyneer , Richard W. Wilson

Adaptive optics (AO) systems using tomographic estimation of three-dimensional structure of atmospheric turbulence requires vertical atmospheric turbulence profile, which describes turbulence strength as a function of altitude as a prior…

Instrumentation and Methods for Astrophysics · Physics 2021-04-21 Hajime Ogane , Masayuki Akiyama , Shin Oya , Yoshito Ono

We describe the implementation of a robotic SLODAR instrument at the Cerro Paranal observatory. The instrument measures the vertical profile of the optical atmospheric turbulence strength, in 8 resolution elements, to a maximum altitude…

Instrumentation and Methods for Astrophysics · Physics 2020-01-08 T. Butterley , R. W. Wilson , M. Sarazin , C. M. Dubbeldam , J. Osborn , P. Clark

We investigate the dynamic response of flexible aircraft in low-altitude atmospheric turbulence. To this end, three turbulence models of increasing fidelity, namely, the one-dimensional von K{\'a}rm{\'a}n model, the two-dimensional Kaimal…

Fluid Dynamics · Physics 2020-03-27 Georgios Deskos , Alfonso del Carre , Rafael Palacios

Quasi-static aberrations in coronagraphic systems are the ultimate limitation to the capabilities of exoplanet imagers both ground-based and space-based. These aberrations - which can be due to various causes such as optics alignment or…

Instrumentation and Methods for Astrophysics · Physics 2019-07-31 Olivier Herscovici-Schiller , Jean-François Sauvage , Laurent M. Mugnier , Kjetil Dohlen , Arthur Vigan

Disturbances such as atmospheric turbulence and aero-optic effects lead to wavefront aberrations, which degrade performance in imaging and laser propagation applications. Adaptive optics (AO) provide a method to mitigate these effects by…

Signal Processing · Electrical Eng. & Systems 2024-10-17 Jeffrey Utley , Gregery Buzzard , Charles Bouman , Matthew Kemnetz

Image restoration algorithms for atmospheric turbulence are known to be much more challenging to design than traditional ones such as blur or noise because the distortion caused by the turbulence is an entanglement of spatially varying…

Image and Video Processing · Electrical Eng. & Systems 2022-07-26 Zhiyuan Mao , Ajay Jaiswal , Zhangyang Wang , Stanley H. Chan

The Earth's atmosphere affects ground-based astronomical observations. Scattering, absorption, and radiation processes deteriorate the signal-to-noise ratio of the data received. For scheduling astronomical observations it is, therefore,…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 S. Noll , W. Kausch , M. Barden , A. M. Jones , C. Szyszka , S. Kimeswenger , J. Vinther

The Earth's atmosphere is comprised of turbulent layers that result in speckled and blurry images from ground-based visible and infrared observations. Adaptive Optics (AO) systems are employed to measure the perturbed wavefront with a…

Instrumentation and Methods for Astrophysics · Physics 2024-10-03 Zhenxi Du , Saavidra Perera , Daniel Levinstein , Quinn Konopacky , Alex Madurowicz , Bruce Macintosh , Lisa Poyneer , Richard Wilson , Ollie Farley

Phase referencing is a standard calibration procedure in radio interferometry. It allows to detect weak sources by using quasi-simultaneous observations of closeby sources acting as calibrators. Therefore, it is assumed that, for each…

Instrumentation and Methods for Astrophysics · Physics 2011-01-25 I. Marti-Vidal , J. C. Guirado , S. Jimenez-Monferrer , J. M. Marcaide

The modeling of turbulence, whether it be numerical or analytical, is a difficult challenge. Turbulence is amenable to analysis with linear theory if it is subject to rapid distortions, i.e., motions occurring on a time scale that is short…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Bryan M. Johnson

The influence of atmospheric turbulence on acquired imagery makes image interpretation and scene analysis extremely difficult and reduces the effectiveness of conventional approaches for classifying and tracking objects of interest in the…

Computer Vision and Pattern Recognition · Computer Science 2024-09-24 Paul Hill , Nantheera Anantrasirichai , Alin Achim , David Bull
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