The Experts below are selected from a list of 18993 Experts worldwide ranked by ideXlab platform
Olga Korotkova - One of the best experts on this subject based on the ideXlab platform.
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scattering of light from particles with semisoft boundaries
Optics Letters, 2011Co-Authors: Serkan Sahin, Greg Gbur, Olga KorotkovaAbstract:A three-dimensional multi-Gaussian function, being a finite sum of Gaussian functions, is adopted for modeling of a spherically symmetric Scatterer with a semisoft boundary, i.e. such that has continuous and adjustable drop in the index of refraction. A Gaussian sphere and a hard sphere are the two limiting cases when the number of terms in multi-Gaussian distribution is one and infinity, respectively. The effect of the boundary’s softness on the intensity distribution of the scattered wave is revealed. The generalization of the model to random Scatterers with semisoft boundaries is also outlined.
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theory of weak scattering of stochastic electromagnetic fields from deterministic and random media
Physical Review A, 2010Co-Authors: Zhisong Tong, Olga KorotkovaAbstract:The theory of scattering of scalar stochastic fields from deterministic and random media is generalized to the electromagnetic domain under the first-order Born approximation. The analysis allows for determining the changes in spectrum, coherence, and polarization of electromagnetic fields produced on their propagation from the source to the scattering volume, interaction with the Scatterer, and propagation from the Scatterer to the far field. An example of scattering of a field produced by a $\ensuremath{\delta}$-correlated partially polarized source and scattered from a $\ensuremath{\delta}$-correlated medium is provided.
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theory of weak scattering of stochastic electromagnetic fields from deterministic and random media
Physical Review A, 2010Co-Authors: Zhisong Tong, Olga KorotkovaAbstract:The theory of scattering of scalar stochastic fields from deterministic and random media is generalized to the electromagnetic domain under the first-order Born approximation. The analysis allows for determining the changes in spectrum, coherence, and polarization of electromagnetic fields produced on their propagation from the source to the scattering volume, interaction with the Scatterer, and propagation from the Scatterer to the far field. An example of scattering of a field produced by a {delta}-correlated partially polarized source and scattered from a {delta}-correlated medium is provided.
Richard Bamler - One of the best experts on this subject based on the ideXlab platform.
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retrieval of phase history parameters from distributed Scatterers in urban areas using very high resolution sar data
Isprs Journal of Photogrammetry and Remote Sensing, 2012Co-Authors: Yuanyuan Wang, Xiao Xiang Zhu, Richard BamlerAbstract:Abstract In a recent contribution Ferretti and co-workers (Ferretti, A., Fumagalli, A., Novali, F., Prati, C., Rocca, F., Rucci, A., 2011. A new algorithm for processing interferometric data-stacks: SqueeSAR IEEE Transactions on Geoscience and Remote Sensing 49(9), pp. 3460–3470) have proposed the SqueeSAR method, a way to exploit temporally coherent distributed Scatterers in coherent SAR data stacks. Elevation and deformation or subsidence estimates are obtained with accuracy similar as in the well known persistent Scatterer interferometry (PSI). In this paper we propose an alternative approach and provide a first demonstration of the optimal estimation of distributed Scatterers’ phase histories in urban areas. Different to SqueeSAR, we derive phase histories for each distributed Scatterer pixel rather than for groups of pixels. We use the Anderson–Darling statistical test to identify neighboring samples of the same distribution. Prior to covariance matrix estimation required for maximum likelihood estimation we apply a multi-resolution defringe technique. By using TerraSAR-X high resolution spotlight data, it is demonstrated that we are able to retrieve reliable phase histories and motion parameter estimates from distributed Scatterers with signal-to-noise-ratio far below the common range.
Daomu Zhao - One of the best experts on this subject based on the ideXlab platform.
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reciprocity relations for scattering from quasi homogeneous anisotropic media
Optics Communications, 2011Co-Authors: Daomu ZhaoAbstract:Abstract Valid within the accuracy of the first-order Born approximation, we obtain the analytical expressions of the three-dimensional spatial Fourier transforms, which show the reciprocity relations for the scattering of a polychromatic plane wave incident upon a Gaussian-correlated, quasi-homogeneous, anisotropic Scatterer. We find that the spectral degree of coherence of the scattered field is only related with the effective radius of the Scatterer and the normalized spectral density of the scattered field is only related with the correlation length of the Scatterer.
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scattering of light by gaussian correlated quasi homogeneous anisotropic media
Optics Letters, 2010Co-Authors: Daomu ZhaoAbstract:We investigate the case when light is scattered by Gaussian-correlated, quasi-homogeneous, anisotropic media. The analytical expression for the cross-spectral density function of the scattered field that is produced by scattering of a polychromatic plane wave incident upon a Gaussian-correlated, quasi-homogeneous, anisotropic medium is derived by use of a tensor method. Numerical examples are given to illustrate the normalized spectral density and the spectral degree of coherence of the field scattered by the anisotropic Scatterer in contrast with that scattered by the isotropic Scatterer.
Zhisong Tong - One of the best experts on this subject based on the ideXlab platform.
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theory of weak scattering of stochastic electromagnetic fields from deterministic and random media
Physical Review A, 2010Co-Authors: Zhisong Tong, Olga KorotkovaAbstract:The theory of scattering of scalar stochastic fields from deterministic and random media is generalized to the electromagnetic domain under the first-order Born approximation. The analysis allows for determining the changes in spectrum, coherence, and polarization of electromagnetic fields produced on their propagation from the source to the scattering volume, interaction with the Scatterer, and propagation from the Scatterer to the far field. An example of scattering of a field produced by a $\ensuremath{\delta}$-correlated partially polarized source and scattered from a $\ensuremath{\delta}$-correlated medium is provided.
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theory of weak scattering of stochastic electromagnetic fields from deterministic and random media
Physical Review A, 2010Co-Authors: Zhisong Tong, Olga KorotkovaAbstract:The theory of scattering of scalar stochastic fields from deterministic and random media is generalized to the electromagnetic domain under the first-order Born approximation. The analysis allows for determining the changes in spectrum, coherence, and polarization of electromagnetic fields produced on their propagation from the source to the scattering volume, interaction with the Scatterer, and propagation from the Scatterer to the far field. An example of scattering of a field produced by a {delta}-correlated partially polarized source and scattered from a {delta}-correlated medium is provided.
Edwin A Marengo - One of the best experts on this subject based on the ideXlab platform.
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a new theory of the generalized optical theorem in anisotropic media
IEEE Transactions on Antennas and Propagation, 2013Co-Authors: Edwin A MarengoAbstract:A new general approach for the generalized optical cross-section theorem and its particular manifestation, the ordinary optical theorem, is developed for electromagnetic scattering in anisotropic media (corresponding to the Scatterer and the background medium where the Scatterer is embedded). The derived results are based on cross-flux concepts, and interaction and reciprocity relations, and apply under arbitrary incident fields, hence they apply in arbitrary representational domains for the data or scattering matrix. This generalization is demonstrated for arbitrary anisotropic Scatterers embedded in lossless anisotropic background media by means of the so-called modified reciprocity theorem plus duality. A new reactive optical theorem is also derived which clarifies the possibilities and limitations of the extraction of reactive energy storage information of an Scatterer from scattering field data. Fundamental and practical imaging implications of the derived optical theorems are discussed. The developed theory is elaborated for general anisotropic Scatterers embedded in free space via the multipole expansion of the electromagnetic field.
