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A defocused image of a bright single star in a small telescope contains rich information on the optical turbulence, i.e. the seeing. The concept of a novel turbulence monitor based on recording sequences of ring-like intrafocal images and…

Instrumentation and Methods for Astrophysics · Physics 2021-01-13 Andrei Tokovinin

We numerically examine the spatial evolution of the structure of coherent and partially coherent laser beams, including the optical vortices, propagating in turbulent atmospheres. The influence of beam fragmentation and wandering relative…

Optics · Physics 2015-05-19 G. P. Berman , V. N. Gorshkov , S. V. Torous

We present a theory for wave scintillation in the situation with a time-dependent partially coherent source and a time-dependent randomly heterogeneous medium. Our objective is to understand how the scintillation index of the measured…

Optics · Physics 2022-07-20 Josselin Garnier , Knut Solna

Ground layer turbulence is a very important site characterization parameter used to assess the quality of an astronomical site. The Lunar Scintillometer is a simple and effective site-testing device for measuring the ground layer…

Instrumentation and Methods for Astrophysics · Physics 2018-02-02 Avinash Surendran , Padmakar S. Parihar , Ravinder K Banyal , Anusha Kalyaan

Strong turbulence conditions create amplitude aberrations through the effects of near-field diffraction. When integrated over long optical path lengths, amplitude aberrations (seen as scintillation) can nullify local areas in the recorded…

Instrumentation and Methods for Astrophysics · Physics 2020-12-30 Justin R. Crepp , Stanimir O. Letchev , Sam J. Potier , Joshua H. Follansbee , Nicholas T. Tusay

We experimentally demonstrate the ability of a nonlinear self-channeling beam to resist turbulence-induced spreading and scintillation. Spatio-temporal data is presented for an 850-meter long, controlled turbulence range that can generate…

One contribution to the time resolution of a scintillation detector is the signal time spread due to path length variations of the detected photons from a point source. In an experimental study a rectangular scintillator was excited by…

Displaced-beam scintillometer measurements of the turbulence inner-scale length $l_o$ and refractive index structure function $C_n^2$ resolve area-average turbulent fluxes of heat and momentum through the Monin-Obukhov similarity equations.…

Atmospheric and Oceanic Physics · Physics 2014-05-12 Matthew Gruber , Javier Fochesatto , Oscar Hartogensis

This work presents a rigorous statistical and geometric framework for analyzing turbulence-impacted beam propagation and image topology with results obtained using a PMMA slab. The approach models beam intensity distributions as…

Optics · Physics 2025-10-02 Shouvik Sadhukhan , C. S. Narayanamurthy

Terahertz (THz) wireless communications have the potential to realize ultra-high-speed and secure data transfer with miniaturized devices for unmanned aerial vehicle (UAV) communications. Existing THz channel models for aerial scenarios…

Signal Processing · Electrical Eng. & Systems 2023-05-16 Weijun Gao , Chong Han , Zhi Chen

We develop the theory of interstellar scintillation as caused by an irregular plasma having a power-law spatial density spectrum with a spectral exponent of 4 corresponding to a medium with abrupt changes in its density. An ``outer scale''…

Astrophysics · Physics 2009-10-31 Hendrik Lambert , Barney Rickett

We demonstrate experimentally and numerically that the application of a partially coherent beam (PCB) in combination with time averaging leads to a significant reduction in the scintillation index. We use a simplified experimental approach…

Compact radio sources such as pulsars and FRBs undergo scintillation in the interstellar medium (ISM) when scattered images interfere at the observer. ``Scintillometry'' refers to the range of techniques to extract astrometric information…

High Energy Astrophysical Phenomena · Physics 2026-01-30 Dylan L. Jow , Delon Shen

In this paper we develop a new statistical model for the irradiance fluctuations of an unbounded optical wavefront (plane and spherical waves) propagating through a turbulent medium under all irradiance fluctuation conditions in…

Plastic scintillation detectors are increasingly used to measure dose distributions in the context of radiotherapy treatments. Their water-equivalence, real-time response and high spatial resolution distinguish them from traditional…

Medical Physics · Physics 2021-09-22 Emily Cloutier , Louis Archambault , Luc Beaulieu

This paper presents the model-based design and evaluation of an instrument that estimates incident neutron direction using the kinematics of neutron scattering by hydrogen-1 nuclei in an organic scintillator. The instrument design uses a…

Instrumentation and Detectors · Physics 2017-12-13 Kyle Weinfurther , John Mattingly , Erik Brubaker , John Steele

The performance of a scintillating fiber detector prototype for tracking under high rate conditions is investigated. A spatial resolution of about100 micron is aimed for the detector. Further demands are low occupancy and radiation hardness…

High Energy Physics - Experiment · Physics 2007-05-23 E. C. Aschenauer , J. Baehr , V. Gapienko , B. Hoffmann , A. Kharchilava , H. Luedecke , R. Nahnhauer , R. Shanidze

We study propagation of two lowest order Gaussian laser beams with different wavelengths in weak atmospheric turbulence. Using the Rytov approximation and assuming a slow detector we calculate the longitudinal and radial components of the…

Optics · Physics 2009-11-11 Avner Peleg , Jerome V. Moloney

Opaque scintillators are designed to have a short scattering length such that scintillation photons are probabilistically confined to a small region of space about their origin. The benefit of this feature is that information on the…

Instrumentation and Detectors · Physics 2023-02-10 Andrew Wilhelm , Garrett Wendel , Brandon Collins , Doug Cowen , Igor Jovanovic

We report the first measurement of the atmospheric optical turbulence profile using the transmitted beam from a satellite laser communication terminal. A Ring Image Next Generation Scintillation Sensor (RINGSS) instrument for turbulence…

Signal Processing · Electrical Eng. & Systems 2024-05-14 Marcus Birch , Sabino Piazzolla , Preston Hooser , Francis Bennet , Tony Travouillon , William Buehlman
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