Correlations and fluctuations in reflection coefficients for coherent wave propagation in disordered scattering media

1989 ◽  
Vol 40 (12) ◽  
pp. 8284-8289 ◽  
Author(s):  
Lihong Wang ◽  
Shechao Feng
Keyword(s):  
Wave Propagation ◽  
Reflection Coefficients ◽  
Scattering Media ◽  
Coherent Wave

Boundary conditions for the numerical solution of wave propagation problems

Geophysics ◽  
1978 ◽  
Vol 43 (6) ◽  
pp. 1099-1110 ◽  
Author(s):  
Albert C. Reynolds
Keyword(s):  
Wave Propagation ◽  
Reflection Coefficient ◽  
Finite Difference ◽  
Boundary Conditions ◽  
Numerical Solution ◽  
Neumann Boundary ◽  
Synthetic Seismograms ◽  
Neumann Boundary Conditions ◽  
Numerical Calculations ◽  
Reflection Coefficients

Many finite difference models in use for generating synthetic seismograms produce unwanted reflections from the edges of the model due to the use of Dirichlet or Neumann boundary conditions. In this paper we develop boundary conditions which greatly reduce this edge reflection. A reflection coefficient analysis is given which indicates that, for the specified boundary conditions, smaller reflection coefficients than those obtained for Dirichlet or Neumann boundary conditions are obtained. Numerical calculations support this conclusion.

scholarly journals Strains analysis at the wave propagation throught he contact layer of the elastic solids

2020 ◽  
pp. 89-96
Author(s):  
N.B. Chertova ◽  
◽  
Yu.V. Grinyaev ◽  
Keyword(s):  
Wave Propagation ◽  
Strain Distribution ◽  
Strain State ◽  
Strain Analysis ◽  
Contact Layer ◽  
Reflection Coefficients ◽  
Block Medium ◽  
Elastic Solids ◽  
Elastic Parameters ◽  
Analytical Expressions

The stress-strain state on the interface of the elastic solids is investigated. The studied interface presents a contact layer which is characterized by dimension and the set of physics mechanical parameters. The models of layered and block medium are used for the description this boundary. In the framework of these models the problem of elastic wave propagation through the interface is considered. Analytical expressions for the refraction and reflection coefficients allowing us to determine the strains on the interface and strains distribution in the contact layer are found. Corresponding strains amplitudes depending on the layer thickness are calculated at the different elastic parameters of contacting solids and boundary. The strain laws on the interface which is described by the layered and block medium models are analyzed. The regions of equivalent use these models are determined in the case of strain analysis on the boundary and the strain distribution in the contact layer.

Mathematical basis for analysis of partially coherent wave propagation in nonlinear, non-instantaneous, Kerr media

2008 ◽  
Vol 41 (33) ◽  
pp. 335207 ◽  
Author(s):  
V Semenov ◽  
M Lisak ◽  
D Anderson ◽  
T Hansson ◽  
L Helczynski-Wolf ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Mathematical Basis ◽  
Kerr Media ◽  
Partially Coherent ◽  
Coherent Wave

Frequency-resolved interferometer measurements of polarized wave propagation in scattering media

2005 ◽  
Vol 22 (12) ◽  
pp. 2691 ◽  
Author(s):  
Timothy D. Gerke ◽  
Mark A. Webster ◽  
Andrew M. Weiner ◽  
Kevin J. Webb
Keyword(s):  
Wave Propagation ◽  
Scattering Media

TARGET CHARACTERIZATION USING TIME-REVERSAL SYMMETRY OF WAVE PROPAGATION

2007 ◽  
Vol 21 (20) ◽  
pp. 3511-3555 ◽  
Author(s):  
D. H. CHAMBERS
Keyword(s):  
Wave Propagation ◽  
Electromagnetic Scattering ◽  
Time Reversal ◽  
Imaging Techniques ◽  
Singular Value ◽  
Time Reversal Symmetry ◽  
Scattering Media ◽  
Open Problems ◽  
Starting Point ◽  
Target Characterization

Over the last 15 years, there has been rapid growth in applications of time-reversal symmetry of wave propagation to enhance communications and imaging through highly scattering media. These techniques exploit both temporal and spatial reciprocity to mitigate signal distortion created from the large number of independent propagation paths between a transmitter and receiver. The time-reversal process is often described by the time-reversal operator (TRO), or equivalently by the multistatic response matrix (MRM), defined by the transmit and receive system. A singular value decomposition of this operator (or MRM) is the starting point for many of the time-reversal imaging techniques. In addition to imaging, this decomposition can also be used to extract information about objects embedded within the propagation medium, i.e., target characterization. In this paper, we review the development of target characterization in time-reversal, with an emphasis on extracting information from small targets. We will analyze the MRM for both acoustic and electromagnetic scattering and show how the symmetry of the target is reflected in the properties of the singular value spectrum. Finally, we discuss several open problems and potential applications.

REFLECTION OF PLANE WAVES FROM A LINEAR TRANSITION LAYER IN LIQUID MEDIA

Geophysics ◽  
1965 ◽  
Vol 30 (1) ◽  
pp. 122-132 ◽  
Author(s):  
Ravindra N. Gupta
Keyword(s):  
Wave Propagation ◽  
Bulk Modulus ◽  
Transition Layer ◽  
Plane Waves ◽  
Reflection Coefficients ◽  
Liquid Media ◽  
Approximation Solution ◽  
High Frequencies ◽  
First Order ◽  
Plane Wave Propagation

It is shown that care should be taken in using the term “velocity” in connection with wave propagation in inhomogeneous media. An expression is derived for phase velocity which depends on frequency and depth. Exact solutions are found for normal and oblique incidence, for plane‐wave propagation in a liquid medium in which density, ρ, and bulk modulus, λ, vary as follows: [Formula: see text] and [Formula: see text] where [Formula: see text], [Formula: see text], b, and p are arbitrary constants. It is shown that the geometrical optics approximation solution, valid for high frequencies, is the first term in an asymptotic expansion of the exact solution. The reflection coefficients are obtained for a linear transition layer between two homogeneous half‐spaces. Both first‐order and second‐order discontinuities in density and bulk modulus are considered at the boundaries of the transition layer.

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