SuperfluidH3ein globally isotropic random media

In geophysics, the geoelectric (dc), magnetotelluric (MT), and transient electromagnetic (TEM) measuring procedures are commonly used to investigate electrical properties of the ground. Finite difference codes are available for all these methods and, in this paper, the data obtained from numerical simulations are compared with regard to two‐component cubic random lattices. Provided the usage of a convenient normalization procedure, it was expected that in case of statistically homogeneous and isotropic random lattices dc, MT, and TEM would yield the same results. Surprisingly, this is not true for the MT data; the lowest MT conductivities are only one‐fifth of the corresponding TEM values.

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Effective permittivity of log-normal isotropic random media

Journal of Physics A General Physics ◽

10.1088/0305-4470/28/3/022 ◽

1995 ◽

Vol 28 (3) ◽

pp. 693-700 ◽

Cited By ~ 34

Author(s):

B Abramovich ◽

P Indelman

Keyword(s):

Random Media ◽

Effective Permittivity ◽

Log Normal ◽

Isotropic Random

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Method of spherical phase screens for the modeling of propagation of diverging beams in inhomogeneous media

ITM Web of Conferences ◽

10.1051/itmconf/20193015027 ◽

2019 ◽

Vol 30 ◽

pp. 15027

Author(s):

Michael E. Gorbunov ◽

Oksana A. Koval ◽

Victor A. Kulikov ◽

Alexey E. Mamontov

Keyword(s):

Random Media ◽

Radio Occultation ◽

Inhomogeneous Media ◽

Phase Screen ◽

Step Method ◽

Atmospheric Path ◽

Cylindrical Phase ◽

Phase Thickness ◽

Phase Screens ◽

Isotropic Random

The phase-screen (split-step) method is widely used for the modeling of wave propagation in inhomogeneous media. Most known is the method of flat phase screens. An optimized approach based on cylindrical phase screen was introduced for the 2-D modeling of radio occultation sounding of the Earth’s atmosphere. In this paper, we propose a further generalization of this method for the 3-D problem of propagation of diverging beams. Our generalization is based on spherical phase screens. In the paraxial approximation, we derive the formula for the vacuum screen- to-screen propagator. We also derive the expression for the phase thickness of a thin layer of an isotropic random media. We describe a numerical implementation of this method and give numerical examples of its application for the modeling of a diverging laser beam propagating on a 25 km long atmospheric path.

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