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Related papers: Accurate measurement of Cn2 profile with Shack-Har…

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Cn2 profile monitoring usually makes use of wavefront slope correlations or of scintillation pattern correlations. Wavefront slope correlations provide sensitivity to layers close to the receiving plane. In addition, scintillation…

Instrumentation and Methods for Astrophysics · Physics 2015-03-17 Clélia Robert , Juliette Voyez , Nicolas Védrenne , Laurent Mugnier

COupled SLope and scIntillation Detection And Ranging (CO-SLIDAR) is a recent profiling method of the vertical distribution of atmospheric turbulence strength ($C_n^2$ profile). It takes advantage of correlations of slopes and of…

Atmospheric and Oceanic Physics · Physics 2015-06-18 Juliette Voyez , Clélia Robert , Jean-Marc Conan , Laurent M. Mugnier , Etienne Samain , Aziz Ziad

CO-SLIDAR is a very promising technique for the metrology of near ground $C_n^2$ profiles. It exploits both phase and scintillation measurements obtained with a dedicated wavefront sensor and allows profiling on the full line of sight…

Instrumentation and Methods for Astrophysics · Physics 2021-12-01 Chloé Sauvage , Clélia Robert , Laurent M. Mugnier , Jean-Marc Conan , Jean-Martial Cohard , Khanh Linh Nguyen , Mark Irvine , Jean-Pierre Lagouarde

The next generation of adaptive optics (AO) systems will require tomographic reconstruction techniques to map the optical refractive index fluctuations, generated by the atmospheric turbulence, along the line of sight to the astronomical…

Instrumentation and Methods for Astrophysics · Physics 2014-01-07 H. W. Shepherd , J. Osborn , R. W. Wilson , T. Butterley , R. Avila , V. S. Dhillon , T. J. Morris

Atmospheric turbulence strength (Cn2 parameter) sensing based on processing of intensity scintillation patterns with deep neural network (DNN) is considered. It is shown that DNN re-training with propagation distance change can be avoided…

Atmospheric and Oceanic Physics · Physics 2022-10-06 G. A. Filimonov , M. A. Vorontsov

We use spatio-temporal cross-correlations of slopes from five Shack-Hartmann wavefront sensors to analyse the temporal evolution of the atmospheric turbulence layers at different altitudes. The focus is on the verification of the frozen…

Instrumentation and Methods for Astrophysics · Physics 2014-02-28 Andrés Guesalaga , Benoit Neichel , Angela Cortes , Clémentine Béchet , Dani Guzmán

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

Images captured from a long distance suffer from dynamic image distortion due to turbulent flow of air cells with random temperatures, and thus refractive indices. This phenomenon, known as image dancing, is commonly characterized by its…

Computer Vision and Pattern Recognition · Computer Science 2024-08-30 Ripon Kumar Saha , Esen Salcin , Jihoo Kim , Joseph Smith , Suren Jayasuriya

We have developed a new software to perform the measurement of galaxy cluster pressure profiles from high angular resolution thermal SZ observations. The code allows the user to take into account various features of millimeter observations,…

Knowledge of the optical refractive index structure parameter $C_n^2$ is of interest for Free Space Optics (FSO) and ground-based optical astronomy, as it depicts the strength of the expected scintillation on the received optical waves.…

Signal Processing · Electrical Eng. & Systems 2023-01-24 Florian Quatresooz , Danielle Vanhoenacker-Janvier , Claude Oestges

The Shack-Hartmann wavefront sensor is widely used to measure aberrations induced by atmospheric turbulence in adaptive optics systems. However if there exists strong atmospheric turbulence or the brightness of guide stars is low, the…

Instrumentation and Methods for Astrophysics · Physics 2021-04-14 Peng Jia , Mingyang Ma , Dongmei Cai , Weihua Wang , Juanjuan Li , Can Li

Scintillation detectors are essential tools for radiation measurement, but calibrating them accurately can be challenging, especially when full-energy peaks are not prominent. This is common in detectors like plastic scintillators. Current…

Instrumentation and Detectors · Physics 2025-10-06 Yanbiao Zhang , Fanjie Zeng , Dehua Kong , Lian Lei , Zhonghai Wang

Accurate high-resolution vertical profiles of optical turbulence ($C_n^2$), which reflect local meteorology and topography, are crucial for ground-based optical astronomy and free-space optical communication. However, measuring these…

Atmospheric and Oceanic Physics · Physics 2026-04-13 Maximilian Pierzyna , Sukanta Basu , Rudolf Saathof

The performance of adaptive optics systems employing sodium laser guide stars can be improved by continuously monitoring the vertical density structure of mesospheric sodium along the line of sight. We demonstrate that sodium density…

Instrumentation and Methods for Astrophysics · Physics 2020-04-01 Joschua A. Hellemeier , Domenico Bonaccini Calia , Paul Hickson , Angel Otarola , Thomas Pfrommer

This work proposes a novel SLAM framework for stereo and visual inertial odometry estimation. It builds an efficient and robust parametrization of co-planar points and lines which leverages specific geometric constraints to improve camera…

Robotics · Computer Science 2020-09-29 Xin Li , Yanyan Li , Evin Pınar Örnek , Jinlong Lin , Federico Tombari

A characterization of the optical turbulence vertical distribution (Cn2 profiles) and all the main integrated astroclimatic parameters derived from the Cn2 and the wind speed profiles above the site of the Large Binocular Telescope (Mt.…

Instrumentation and Methods for Astrophysics · Physics 2010-11-29 E. Masciadri , J. Stoesz , S. Hagelin , F. Lascaux

We present a self-supervised approach for characterizing low surface brightness tidal features in wide-field imaging data by applying the nearest-neighbor contrastive learning of visual representations (NNCLR) algorithm to a curated subset…

Astrophysics of Galaxies · Physics 2026-02-02 Ernesto Benitez-Walz , Jelle Mes , Juan Miró-Carretero , Koen Kuijken , Amina Helmi

Neutron correlation spectroscopy can exceed direct spectroscopy in the incoming beam intensity by up to two orders of magnitude at the same energy resolution. However, the propagation of the counting noise in the correlation algorithm of…

Instrumentation and Detectors · Physics 2016-09-13 F. Mezei , M. T. Caccamo , F. Migliardo , S. Magazù

This study shows an implementation of neutron-gamma pulse shape discrimination (PSD) using a two-dimensional convolutional neural network. The inputs to the network are snapshots of the unprocessed, digitized signals from a BC501A detector.…

Instrumentation and Detectors · Physics 2023-06-19 Annesha Karmakar , Anikesh Pal , G. Anil Kumar , Bhavika , V. Anand , Mohit Tyagi

Shack Hartmann wavefront sensor is a two dimensional array of lenslets which is used to detect the incoming phase distorted wavefront through local tilt measurements made by recording the spot pattern near the focal plane. Wavefront…

Instrumentation and Methods for Astrophysics · Physics 2011-08-16 Akondi Vyas , M B Roopashree , B Raghavendra Prasad
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