English
Related papers

Related papers: Measuring Local Turbulence Along the Optical Path:…

200 papers

A long-held vision has been to realize diffraction-limited optical aperture synthesis over kilometer baselines. This will enable imaging of stellar surfaces and their environments, and reveal interacting gas flows in binary systems. An…

Instrumentation and Methods for Astrophysics · Physics 2015-08-12 Dainis Dravins , Tiphaine Lagadec , Paul D. Nuñez

We describe a new model for image propagation through open air in the presence of changes in the index of refraction (e.g. due to turbulence) using the theory of optimal transport. We describe the relationship between photon density, or…

In many practical applications of long-range imaging such as biometrics and surveillance, thermal imagining modalities are often used to capture images in low-light and nighttime conditions. However, such imaging systems often suffer from…

Computer Vision and Pattern Recognition · Computer Science 2022-04-08 Kangfu Mei , Yiqun Mei , Vishal M. Patel

The accuracy of ground-based astronomical photometry is limited by two factors: photon statistics and stellar scintillation arising when star light passes through Earth's atmosphere. This paper examines the theoretical role of the outer…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Victor Kornilov

Ground-based solar observations are severely affected by Earth's turbulent atmosphere. As a consequence, observed image quality and prevailing seeing conditions are closely related. Partial correction of image degradation is nowadays…

Instrumentation and Methods for Astrophysics · Physics 2021-02-10 Robert Kamlah , Meetu Verma , Andrea Diercke , Carsten Denker

When molecules whose collision induced vibrational decay rates are small are probed by molecular absorption spectroscopic (MAS) techniques the absorption signal can, under certain conditions, be reduced and distorted. The reason has been…

Atomic Physics · Physics 2018-11-01 Thomas Hausmaninger , Weiguang Ma , Ove Axner

High precision cosmology with weak gravitational lensing requires a precise measure of the Point Spread Function across the imaging data where the accuracy to which high spatial frequency variation can be modelled is limited by the stellar…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Catherine Heymans , Barnaby Rowe , Henk Hoekstra , Lance Miller , Thomas Erben , Thomas Kitching , Ludovic Van Waerbeke

Observations with ground-based telescopes are affected by differential atmospheric dispersion due to the wavelength-dependent index of refraction of the atmosphere. The usage of an Atmospheric Dispersion Corrector (ADC) is fundamental to…

Instrumentation and Methods for Astrophysics · Physics 2020-10-14 B. Wehbe , A. Cabral , G. Avila

A distributed detection scheme where the sensors transmit with constant modulus signals over a Gaussian multiple access channel is considered. The deflection coefficient of the proposed scheme is shown to depend on the characteristic…

Information Theory · Computer Science 2017-04-05 Cihan Tepedelenlioglu , Sivaraman Dasarathan

Channel turbulence is a formidable obstacle for free-space optical (FSO) communication. Anticipation of turbulence levels is highly important for mitigating disruptions but has not been demonstrated without dedicated, auxiliary hardware. We…

Systems and Control · Electrical Eng. & Systems 2025-03-26 Md Zobaer Islam , Ethan Abele , Fahim Ferdous Hossain , Arsalan Ahmad , Sabit Ekin , John F. O'Hara

We present a concept of a millimeter wavefront sensor that allows real-time sensing of the surface of a ground-based millimeter/submillimeter telescope. It is becoming important for ground-based millimeter/submillimeter astronomy to make…

Open-path dual-comb spectroscopy (DCS) significantly enhances our understanding of regional trace gases. However, due to technical challenges, cost considerations, and eye-safety regulations, its sensing range and flexibility remain…

The sky subtraction performances of multi-fiber spectrographs are discussed, analysing in detail the case of the OPTOPUS system at the 3.6 meter ESO telescope at La Silla. A standard technique, based on flat-fields obtained with a uniformly…

Astrophysics · Physics 2009-10-22 C. Lissandrini , S. Cristiani , F. La Franca

Transformation and detection of photons in higher-order spatial modes usually requires complicated holographic techniques. Detectors based on spatial holograms suffer from non-idealities and should be carefully calibrated. We report a novel…

Quantum Physics · Physics 2015-06-23 Ivan Bobrov , Egor Kovlakov , Anton Markov , Stanislav Straupe , Sergey Kulik

We introduce a method to experimentally measure the monochromatic transmission matrix of a complex medium in optics. This method is based on a spatial phase modulator together with a full-field interferometric measurement on a camera. We…

Optics · Physics 2010-03-10 S. M. Popoff , G. Lerosey , R. Carminati , M. Fink , A. C. Boccara , S. Gigan

We develop a weak measurement scheme for measuring orbital angular momentum (OAM) of light based on the global topology in wave function. We introduce the spin-orbit coupling to transform the measurement of OAM to the pre- and postselected…

Optics · Physics 2024-10-02 Junfan Zhu , An Wang , Yurong Liu , Fuhua Gao , Zhiyou Zhang

Weak lensing by large-scale structure allows a direct measure of the dark matter distribution. We have used parallel images taken with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope to measure weak lensing, or…

An Atmospheric Monitoring System (AMS) is a mandatory and key device of a space-based mission which aims to detect Ultra-High Energy Cosmic Rays (UHECR) and Extremely-High Energy Cosmic Rays (EHECR) from Space. JEM-EUSO has a dedicated…

Instrumentation and Methods for Astrophysics · Physics 2015-06-23 M. D. Rodriguez Frias , S. Toscano , E. Bozzo , L. del Peral , A. Neronov , S. Wada

A six-night optical turbulence monitoring campaign has been carried at Cerro Paranal observatory in February and March, 2023 to facilitate the development and characterisation of two novel atmospheric site monitoring instruments - the…

Instrumentation and Methods for Astrophysics · Physics 2024-02-15 Ryan Griffiths , Lisa Bardou , Timothy Butterley , James Osborn , Richard Wilson , Edison Bustos , Andrei Tokovinin , Miska Le Louarn , Angel Otarola

The Profiler of Moon Limb is a recent instrument dedicated to the monitoring of optical turbulence profile of the atmosphere. Fluctuations of the Moon or the Sun limb allow to evaluate the index refraction structure constant C_n^2(h) and…

Instrumentation and Methods for Astrophysics · Physics 2020-02-13 Eric Aristidi , Aziz Ziad , Yan Fantéï-Caujolle , Julien Chabé , Christophe Giordano , Catherine Renaud , Henri Lantéri