Journal ArticleDOI
Some fundamental properties of speckle
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TLDR
In this paper, the distribution of scale sizes in a speckle pattern (i.e., the Wiener spectrum) is investigated from a physical point of view, and it is shown that adding M uncorrelated speckles on an intensity basis can reduce the contrast by 1/√M.Abstract:
A speckle pattern formed in polarized monochromatic light may be regarded as resulting from a classical random walk in the complex plane. The resulting irradiance fluctuations obey negative exponential statistics, with ratio of standard deviation to mean (i.e., contrast) of unity. Reduction of this contrast, or smoothing of the speckle, requires diversity in polarization, space, frequency, or time. Addition of M uncorrelated speckle patterns on an intensity basis can reduce the contrast by 1/√M. However, addition of speckle patterns on a complex amplitude basis provides no reduction of contrast. The distribution of scale sizes in a speckle pattern (i.e., the Wiener spectrum) is investigated from a physical point of view.read more
Citations
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Journal ArticleDOI
Speckle-induced phase error in laser-based phase-shifting projected fringe profilometry
TL;DR: In this paper, the dependence of phase error distribution and measurement uncertainty on speckle size and grating pitch is numerically studied, based on the Karhunen-Loeve expansion method, and an analytical expression that relates phase error distributions to optical system parameters is derived as a direct extension of the simulation results.
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A physical analysis of polarimetric SAR data statistical models
TL;DR: The random walk model is studied with the objective to obtain a physical explanation for the texture of polarimetric synthetic aperture radar (SAR) data and it is found that both the fluctuation of the scatterer number and the mixture of different targets can give non-Gaussian-distributed data.
Journal ArticleDOI
The fractal character of Gaussian-Lorentzian light
TL;DR: In this article, it was demonstrated that intensity time-sequences for this type of light exhibit a fractal character, possessing fluctuations over nearly a three-decade range of timescale, in contrast with the much smoother fluctuations observed for Gaussian-broadened light.
Journal ArticleDOI
A systematic review on recent developments in nonlocal and variational methods for SAR image despeckling
TL;DR: A review of state-of-the-art speckle filtering algorithms for various methods available in the literature is presented in this paper , where different multiplicative noise models in SAR images along with their characteristics are explained.
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Modeling of two-dimensional effects in hot spot relaxation in laser-produced plasmas
TL;DR: In this article, the effects of non-local heat transport on the plasma response are studied comparing the Spitzer-Harm model with several frequently used nonlocal models, and the importance of using a high-order numerical scheme to correctly model nonlocal effects is discussed.
References
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ReportDOI
Statistical properties of laser sparkle patterns
TL;DR: In this article, the first order statistics of the observed electric-field strength, the observed light intensity, and observed light phase are examined, and the autocorrelation functions of the complex field and intensity processes are investigated, and that of the electric field is found to be proportional to the Fourier transform of the light intensity distribution incident on the scattering surface.
Book ChapterDOI
Statistical Properties of Laser Speckle Patterns
TL;DR: In this article, the first-order statistics of the complex amplitude, intensity and phase of speckle are derived for a free-space propagation geometry and for an imaging geometry.
Journal ArticleDOI
Some Aspects of Diffraction Theory and their Application to the Ionosphere
TL;DR: In this paper, the Fourier approach is extended to deal with problems of ''random'' diffraction, for which purpose the use of auto-correlation functions is introduced and explained in physical terms.
Investigation of molecular motions in supercooled liquids by Mossbauer scattering D C Champeney and F W D Woodhams Some Aspects of Diffraction Theory and their Application to the Ionosphere
J A Ratcliffe,D C Champeney +1 more
TL;DR: In this article, the Fourier approach is extended to deal with problems of ''random'' diffraction, for which purpose the use of auto-correlation functions is introduced and explained in physical terms.
Journal ArticleDOI
XII. On the resultant of a large number of vibrations of the same pitch and of arbitrary phase
TL;DR: In this article, the resultant of a large number of vibrations of the same pitch and of arbitrary phase is discussed. But the authors focus on the effect of the phase of the vibrations.