Results 221 to 230 of about 1,686,769 (280)

Energy conservation in the Kirchhoff approximation

The Journal of the Acoustical Society of America, 2011
The scattering of sound from rough interfaces is frequently modeled using the Kirchhoff approximation. As has been shown by Lynch and Wagner [J. Acoust. Soc. Am. 47(3)] and others, for the case of a pressure-release surface, the Kirchhoff approximation fails to conserve energy.
Sumedh M. Joshi, Marcia J. Isakson
openaire   +1 more source

The validity of the Kirchhoff approximation for fractal surface scattering

IEEE 1999 International Geoscience and Remote Sensing Symposium. IGARSS'99 (Cat. No.99CH36293), 2003
In this paper a novel theoretical framework for calculating the mean radius of curvature of fractal surfaces is depicted. In particular, the case of surfaces represented by means of functions belonging to the set of the Weierstrass-Mandelbrot functions is hereafter detailed.
G. FRANCESCHETTI, M. MIGLIACCIO, RICCIO, DANIELE   +2 more
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A general Kirchhoff approximation for echo simulation in ultrasonic NDT

AIP Conference Proceedings, 2012
Michel Darmon, S Chatillon
exaly   +2 more sources

An Approximate Algorithm for a Kirchhoff Wave Equation

SIAM Journal on Numerical Analysis, 2009
The initial boundary value problem for a hyperbolic-type quasilinear equation $w_{tt}=\varphi(\int_0^\pi w_x^2dx)w_{xx}$ is considered. Its solution is derived by means of a numerical algorithm consisting of the projection method and the difference method for approximation with respect to spatial and time variables, while the resulting discrete system ...
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Rough Surfaces : An Improvement Of The Kirchhoff Approximation

SPIE Proceedings, 1989
From very simple theoretical considerations, it is shown that the physical optics approximation can be improved by taking into account the shape of the surface of the diffracting object. The theory has been numerically implemented for both polarizations, as well for perfectly conducting surfaces as for metallic or dielectric ...
D. Maystre, H. Faure-Geors
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A frequency-approximated approach to Kirchhoff migration

Geophysics, 2010
Abstract The integral solution of the wave equation has long been one of the most popular methods for imaging (Kirchhoff migration) and inverting (Kirchhoff inversion) seismic data. For efficiency, this process is commonly formulated as a time-domain operation on each trace, applying antialiasing through high-cut filtering of the ...
Vardy, Mark E., Henstock, Timothy J.
openaire   +2 more sources

Computationally efficient algorithm for Kirchhoff approximation

The Journal of the Acoustical Society of America, 2015
In order to simulate the target echoes scattered from submerged underwater objects, Kirchhoff approximation is widely used for high frequency region. Since Kirchhoff integration is based on integrating the contributions from discretized boundary elements, the computation can be time-consuming especially for broadband pulses.
Donghyeon Kim, Hubum Jin, Yoon Hee Ji, Ho Seuk Bae, Woo-Shik Kim, Jea Soo Kim   +5 more
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The Kirchhoff Approximation in diffuse optical tomography

Biomedical Topical Meeting, 2002
Analytical expressions for Diffuse Optical Tomography are generally limited to simple geometries such as a diffusive slab, a sphere or a cylinder. Imaging of tissues however involves solutions for diffuse media with complex boundaries, in which case the use of numerical methods is directed.
Jorge Ripoll, Vasilis Ntziachristos
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Approximate analytical formulas for Kirchhoff migration operator

Applied Mathematics and Computation, 2005
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
openaire   +3 more sources

A Kirchhoff approximation for surface plasmon polaritons

SPIE Proceedings, 2010
By the use of an impedance boundary condition, the Wiener-Hopf method, and Green's second integral identity in the plane we obtain a Kirchhoff approximation for the reflection amplitude of a surface plasmon polariton incident from one metal surface onto its rough boundary with a co-planar surface of a second metal.
T. A. Leskova, A. A. Maradudin
openaire   +1 more source