Journal ArticleDOI
Some fundamental properties of speckle
Reads0
Chats0
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
More filters
Patent
Diffuser configuration for an image projector
Gang Chen,Roland Ryf +1 more
TL;DR: In this paper, an image projector has a spatial light modulator (SLM) adapted to modulate illumination from a laser with a spatial pattern such that the modulated illumination projects an image on a viewing screen.
Proceedings ArticleDOI
Extraction Of Textural Features In Sar Images: Statistical Model And Sensitivity
Eric Rignot,R. Kwok +1 more
Journal ArticleDOI
A step-by-step guide to reduce spatial coherence of laser light using a rotating ground glass diffuser
TL;DR: In this article, a stepper motor was used to collect the scattered light from the ground glass diffuser to construct a speckle-free and high contrast laser illumination setup.
Journal ArticleDOI
New automatic techniques for smoothing and segmenting SAR images
S.M. Ali,R. E. Burge +1 more
TL;DR: A new algorithm for smoothing synthetic aperture radar (SAR) images, which is based on the estimation of the most homogeneous neighbourhood around each image pixel, is presented.
Proceedings ArticleDOI
Hierarchical MRF modeling for sonar picture segmentation
TL;DR: The designed Markov random field model takes into account both the phenomenon of speckle noise through Rayleigh's law, and notions of geometry related to the shape of object shadows to improve the sonar image segmentation while speeding up the iterative optimization scheme.
References
More filters
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.