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The stellar scintillation is one of the fundamental limitation to the precision of ground-based photometry. The paper examines the problem of correlation of the scintillation of two close stars at the focus of a large telescope. The derived…

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

Diffusing-Wave Spectroscopy (DWS) treats the transport of photons through turbid samples as a diffusion process, thereby making it possible to extract the dynamics of scatterers from measured correlation functions. The analysis of DWS data…

Soft Condensed Matter · Physics 2017-12-27 Zahra Fahimi , Frank Aangenendt , Panayiotis Voudouris , Johan Mattson , Hans M. Wyss

In the stably stratified ocean, small-scale turbulence is important for vertical exchange and hence for the mixing of water masses and suspended matter. To observationally study turbulent motions and the buoyancy- and shear-generators…

Atmospheric and Oceanic Physics · Physics 2022-09-23 Hans van Haren

We continue our work on developing techniques for studying turbulence with spectroscopic data. We show that Doppler-broadened absorption spectral lines, in particularly, saturated absorption lines, can be used within the framework of the…

Astrophysics · Physics 2009-11-13 A. Lazarian , D. Pogosyan

In this paper, we build an apparatus for measuring the optical transmittance and its uniformity for a semispherical surface at normal incidence; the system is primarily comprised of a traditional double-beam photometric framework and a…

Optics · Physics 2018-05-23 Shenghao Wang , Shijie Liu , Jianda Shao , Tianzhu Xu , Qi Lu , Shen Qi , Minghui Feng , Long Zhang

Intensity scintillations of radio pulsars are known to originate from interference between waves scattered by the electron density irregularities of interstellar plasma, often leading to parabolic arcs in the two-dimensional power spectrum…

Electron density irregularities present within the ionosphere induce significant fluctuations in global navigation satellite system (GNSS) signals. Fluctuations in signal power are referred to as amplitude scintillation and can be monitored…

Machine Learning · Computer Science 2022-10-03 Abdollah Masoud Darya , Aisha Abdulla Al-Owais , Muhammad Mubasshir Shaikh , Ilias Fernini

MHD Turbulence is a critical component of the current paradigms of star formation, particle transport, magnetic reconnection and evolution of the ISM. Progress on this difficult subject is made via numerical simulations and observational…

Astrophysics of Galaxies · Physics 2011-05-06 Blakesley Burkhart , Alex Lazarian

We obtain high spatial and spectral resolution images of the CO J=2-1, CN N=2-1 and CS J=5-4 emission with ALMA in Cycle~2. The radial distribution of the turbulent broadening is derived with three approaches: two `direct' and one…

One of the main goals of the feasibility study MOSE (MOdellig ESO Sites) is to evaluate the performances of a method conceived to forecast the optical turbulence above the ESO sites of the Very Large Telescope and the European-Extremely…

Instrumentation and Methods for Astrophysics · Physics 2016-12-05 Elena Masciadri , Franck Lascaux , Alessio Turchi , Luca Fini

Fiber-optic sensing technologies based on transmission offer an alternative to scattering-based Distributed Acoustic Sensing (DAS). Being able to interrogate fibers that are thousands of kilometers long, opens opportunities for…

Observations of interplanetary scintillation (IPS - the scintillation of compact radio sources due to density variations in the solar wind) enable the velocity of the solar wind to be determined, and its bulk density to be estimated,…

Solar and Stellar Astrophysics · Physics 2022-10-06 R. A. Fallows , K. Iwai , B. V. Jackson , P. Zhang , M. M. Bisi , P. Zucca

The simulation of the optical turbulence (OT) for astronomical applications obtained with non-hydrostatic atmospherical models at meso-scale presents, with respect to measurements, some advantages. The future of the ground-based astronomy…

Instrumentation and Methods for Astrophysics · Physics 2014-11-20 E. Masciadri

The cosmic expansion rate can be directly measured with gravitational-wave (GW) data of the compact binary mergers by jointly constraining the mass function of the population and the cosmological model via the so-called spectral sirens.…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-12 Yin-Jie Li , Shao-Peng Tang , Yuan-Zhu Wang , Yi-Zhong Fan

Synthetic aperture radar (SAR) has a pivotal role as a remote imaging method. Obtained by means of coherent illumination, SAR images are contaminated with speckle noise. The statistical modeling of such contamination is well described…

Computation · Statistics 2012-07-11 Renato J. Cintra , Abraão D. C. Nascimento , Alejandro C. Frery

This paper proposes a unified statistical channel model to characterize the atmospheric turbulence induced distortions faced by orbital angular momentum (OAM) in free space optical (FSO) communication systems. In this channel model, the…

Signal Processing · Electrical Eng. & Systems 2019-10-24 El-Mehdi Amhoud , Boon S. Ooi , Mohamed-Slim Alouini

Monitoring turbulence parameters is crucial in high-angular resolution astronomy for various purposes, such as optimising adaptive optics systems or fringe trackers. The former are present at most modern observatories and will remain…

Instrumentation and Methods for Astrophysics · Physics 2023-10-25 Nuno Morujão , Carlos Correia , Paulo Andrade , Julien Woillez , Paulo Garcia

We report on findings from scintillation analyses using high-cadence observations of eight canonical pulsars with observing baselines ranging from one to three years. We obtain scintillation bandwidth and timescale measurements for all…

This paper describes the data preprocessing and reduction methods together with SLODAR analysis and wind profiling techniques for GeMS: the Gemini MCAO System. The wavefront gradient measurements of the five GeMS's Shack-Hartmann sensors,…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Angela Cortés , Benoit Neichel , Andrés Guesalaga , James Osborn , Francois Rigaut , Dani Guzman

We propose a new method to detect off-pulse (unpulsed and/or continuous) emission from pulsars, using the intensity modulations associated with interstellar scintillation. Our technique involves obtaining the dynamic spectra, separately for…

High Energy Astrophysical Phenomena · Physics 2018-05-23 Kumar Ravi , Avinash A. Deshpande