Journal ArticleDOI
Inner-scale effect on irradiance variance measured for weak-to-strong atmospheric scintillation
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In this paper, experiments of measurements of irradiance fluctuations of laser radiation through atmospheric turbulence were described, and the effect of the inner scale on the intensity of the irradiance fluctuation was investigated.Abstract:
Experimental results are described of measurements of irradiance fluctuations of laser radiation through atmospheric turbulence Simultaneous measurements of irradiance fluctuations, inner scale, and structure parameter were made in conditions of homogeneous turbulence during a number of summer days, from very early in the morning, before sunrise, until approximately noon During the measurements the turbulence strength varied continuously, spanning very low as well as intermediate and very high levels We used the data collected in selected intervals, during which turbulence was stationary, to obtain plots of irradiance variance versus the structure parameter for fixed ranges of values of the inner scale The results clearly show the effect of the inner scale For a given value of the structure parameter larger inner scales result in larger values of irradiance variance in the regime of strong scintillationread more
Citations
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Survey on Free Space Optical Communication: A Communication Theory Perspective
TL;DR: An up-to-date survey on FSO communication systems is presented, describing FSO channel models and transmitter/receiver structures and details on information theoretical limits of FSO channels and algorithmic-level system design research activities to approach these limits are provided.
Journal ArticleDOI
Mathematical model for the irradiance probability density function of a laser beam propagating through turbulent media
TL;DR: In this article, the authors developed a model for the probability density function (pdf) of the irradiance fluctuations of an optical wave propagating through a turbulent medium, which is a two-parameter distribution that is based on a doubly stochastic theory of scintillation.
Journal ArticleDOI
Theory of optical scintillation
TL;DR: In this article, a heuristic model of irradiance fluctuations for a propagating optical wave in a weakly inhomogeneous medium is developed under the assumption that small-scale irradiance fluctuation fluctuations are modulated by large-scale fluctuations of the wave.
Journal ArticleDOI
Fading Reduction by Aperture Averaging and Spatial Diversity in Optical Wireless Systems
TL;DR: This paper quantifies the performance improvement in terms of average bit error rate (BER) and outage capacity, which are among important parameters in practice, and compares single- and multiple-aperture systems from the point of view of fading reduction.
Journal ArticleDOI
Theory of optical scintillation: Gaussian-beam wave model
TL;DR: In this article, a scintillation model was extended to the case of a propagating Gaussian-beam wave and the effect of a finite outer scale in addition to the inner scale was considered.
References
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Journal ArticleDOI
Intensity images and statistics from numerical simulation of wave propagation in 3-D random media
J. M. Martin,Stanley M. Flatté +1 more
TL;DR: An extended random medium is modeled by a set of 2-D thin Gaussian phase-changing screens with phase power spectral densities appropriate to the natural medium being modeled, showing that under weak scattering the small-scale Fresnel length structure of the medium dominates the intensity scattering pattern.
Structure of Temperature Field in Turbulent Flow
TL;DR: In this article, the mean square of the temperature difference at two points is used as the characteristic parameter of temperature field and the dependence of this quantity on the distance between the points of observation is determined experimentally.
Journal ArticleDOI
Models of the scalar spectrum for turbulent advection
TL;DR: In this paper, several models are developed for the high-wavenumber portion of the spectral transfer function of scalar quantities advected by high-Reynolds-number, locally isotropic turbulent flow.
Journal ArticleDOI
Modified spectrum of atmospheric temperature fluctuations and its application to optical propagation
Reginald J. Hill,S. F. Clifford +1 more
TL;DR: In this paper, an accurate model of the spectra of advected quantities, such as temperature, has been developed and is applied here to optical propagation, and the model is used to compute the temperature structure function, the variance of log intensity as a function of Fresnel-zone size, the covariance function of log amplitude, the structure function of phase, as well as the phase coherence length.
Journal ArticleDOI
Simulation of point-source scintillation through three-dimensional random media
J. M. Martin,Stanley M. Flatté +1 more
TL;DR: In this paper, the intensity spectra and variances for waves emanating from a point source and propagating through extended three-dimensional random media by simulation were calculated and the results agree reasonably closely with the results of laser propagation experiments over kilometer-length paths in the atmosphere.