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First-Principles Modeling Of Electromagnetic Scattering By Discrete and Discretely Heterogeneous Random MediaA discrete random medium is an object in the form of a finite volume of a vacuum or a homogeneous material medium filled with quasi-randomly and quasi-uniformly distributed discrete macroscopic impurities called small particles. Such objects are ubiquitous in natural and artificial environments. They are often characterized by analyzing theoretically the results of laboratory, in situ, or remote-sensing measurements of the scattering of light and other electromagnetic radiation. Electromagnetic scattering and absorption by particles can also affect the energy budget of a discrete random medium and hence various ambient physical and chemical processes. In either case electromagnetic scattering must be modeled in terms of appropriate optical observables, i.e., quadratic or bilinear forms in the field that quantify the reading of a relevant optical instrument or the electromagnetic energy budget. It is generally believed that time-harmonic Maxwell's equations can accurately describe elastic electromagnetic scattering by macroscopic particulate media that change in time much more slowly than the incident electromagnetic field. However, direct solutions of these equations for discrete random media had been impracticable until quite recently. This has led to a widespread use of various phenomenological approaches in situations when their very applicability can be questioned. Recently, however, a new branch of physical optics has emerged wherein electromagnetic scattering by discrete and discretely heterogeneous random media is modeled directly by using analytical or numerically exact computer solutions of the Maxwell equations. Therefore, the main objective of this Report is to formulate the general theoretical framework of electromagnetic scattering by discrete random media rooted in the Maxwell- Lorentz electromagnetics and discuss its immediate analytical and numerical consequences. Starting from the microscopic Maxwell-Lorentz equations, we trace the development of the first principles formalism enabling accurate calculations of monochromatic and quasi-monochromatic scattering by static and randomly varying multiparticle groups. We illustrate how this general framework can be coupled with state-of-the-art computer solvers of the Maxwell equations and applied to direct modeling of electromagnetic scattering by representative random multi-particle groups with arbitrary packing densities. This first-principles modeling yields general physical insights unavailable with phenomenological approaches. We discuss how the first-order-scattering approximation, the radiative transfer theory, and the theory of weak localization of electromagnetic waves can be derived as immediate corollaries of the Maxwell equations for very specific and well-defined kinds of particulate medium. These recent developments confirm the mesoscopic origin of the radiative transfer, weak localization, and effective-medium regimes and help evaluate the numerical accuracy of widely used approximate modeling methodologies.
Document ID
20170004359
Acquisition Source
Goddard Space Flight Center
Document Type
Accepted Manuscript (Version with final changes)
Authors
Michael I Mishchenko
(Goddard Institute for Space Studies New York, New York, United States)
Janna M Dlugach
(National Academy of Sciences of Ukraine Kyiv, Ukraine)
Maxim A Yurkin
(Novosibirsk State University Novosibirsk, Russia)
Lei Bi
(Texas A&M University System College Station, Texas, United States)
Brian Cairns
(Goddard Institute for Space Studies New York, New York, United States)
Li Liu
(Columbia University New York, New York, United States)
R Lee Panetta
(Texas A&M University System College Station, Texas, United States)
Larry D Travis
(Goddard Institute for Space Studies New York, New York, United States)
Ping Yang
(Texas A&M University System College Station, Texas, United States)
Nadezhda Zakharova
(Trinnovim, LLC New York, NY, United States)
Date Acquired
May 3, 2017
Publication Date
April 12, 2016
Publication Information
Publication: Physics Reports
Publisher: Elsevier
Volume: 632
Issue Publication Date: May 16, 2016
ISSN: 0370-1573
Subject Category
Physics Of Elementary Particles And Fields
Report/Patent Number
GSFC-E-DAA-TN31534
GSFC-E-DAA-TN40267
Funding Number(s)
CONTRACT_GRANT: NNG12HP07C
CONTRACT_GRANT: NNX15AJ05A
Distribution Limits
Public
Copyright
Public Use Permitted.
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