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
Posted Content
SAR Image Despeckling Algorithms using Stochastic Distances and Nonlocal Means.
TL;DR: Two approaches for filter design based on stochastic distances for intensity speckle reduction based on a Nagao-Matsuyama-type procedure and a nonlocal method are presented.
Book ChapterDOI
1 – Synthetic Aperture Radar Imaging
Laurent Ferro-Famil,Eric Pottier +1 more
TL;DR: Synthetic aperture radar (SAR) imaging is a technique that allows us to remotely map the reflectivity of objects or environments with high spatial resolution, through the emission and reception of electromagnetic (EM) signals as mentioned in this paper.
Journal ArticleDOI
Analyzing the Total Structural Intensity in Beams Using a Homodyne Laser Doppler Vibrometer
Agnaldo A. Freschi,Allan K. A. Pereira,Khaled M. Ahmida,Jaime Frejlich,José Roberto de França Arruda +4 more
TL;DR: In this article, a twisted z-shaped beam is used in order to allow the three types of waves to propagate, and the contributions of the structural intensity, due to these waves, are computed from measurements taken over the surface of the beam with a simple homodyne interferometric laser vibrometer.
Proceedings ArticleDOI
Analysis of Denoising Techniques for Speckle Noise Removal in Synthetic Aperture Radar Images
TL;DR: Experimental results of applying different noise reduction techniques on ALOS PALSAR data has been demonstrated and investigations were performed on these techniques out of which Intensity Driven Adaptive Neighborhood (IDAN) and Median filter technique perform better smoothing than other methods.
Journal ArticleDOI
A Method of Speckle Noise Reduction for SAR Data
Hiroyuki Wakabayashi,Kohei Arai +1 more
TL;DR: Although the proposed CST filter does not use any templates to preserve structured targets, it showed almost same performance to preserve edge and point targets as the other structure preservation filters.
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.