Book contents
- Frontmatter
- Dedication
- Contents
- Preface
- Acknowledgments
- Acronyms
- 1 Introduction
- 2 The macroscopic Maxwell equations and monochromatic fields
- 3 Fundamental homogeneous-medium solutions of the macroscopic Maxwell equations
- 4 Basic theory of frequency-domain electromagnetic scattering by a fixed finite object
- 5 Far-field scattering
- 6 The Foldy equations
- 7 The Stokes parameters
- 8 Poynting–Stokes tensor
- 9 Polychromatic electromagnetic fields
- 10 Polychromatic scattering by fixed and randomly changing objects
- 11 Measurement of electromagnetic energy flow
- 12 Measurement of the Stokes parameters
- 13 Description of far-field scattering in terms of actual optical observables
- 14 Electromagnetic scattering by a small random group of sparsely distributed particles
- 15 Statistically isotropic and mirror-symmetric random particles
- 16 Numerical computations and laboratory measurements of electromagnetic scattering
- 17 Far-field observables: qualitative and quantitative traits
- 18 Electromagnetic scattering by discrete random media: far field
- 19 Near-field scattering by a sparse discrete random medium: microphysical radiative transfer theory
- 20 Radiative transfer in plane-parallel particulate media
- 21 Weak localization
- 22 Epilogue
- Appendix A Dyads and dyadics
- Appendix B Free-space dyadic Green's function
- Appendix C Euler rotation angles
- Appendix D Spherical-wave decomposition of a plane wave in the far zone
- Appendix E Integration quadrature formulas
- Appendix F Wigner d-functions
- Appendix G Stationary phase evaluation of a double integral
- Appendix H Hints and answers to selected problems
- References
- Index
- Plate Section
19 - Near-field scattering by a sparse discrete random medium: microphysical radiative transfer theory
Published online by Cambridge University Press: 05 July 2014
- Frontmatter
- Dedication
- Contents
- Preface
- Acknowledgments
- Acronyms
- 1 Introduction
- 2 The macroscopic Maxwell equations and monochromatic fields
- 3 Fundamental homogeneous-medium solutions of the macroscopic Maxwell equations
- 4 Basic theory of frequency-domain electromagnetic scattering by a fixed finite object
- 5 Far-field scattering
- 6 The Foldy equations
- 7 The Stokes parameters
- 8 Poynting–Stokes tensor
- 9 Polychromatic electromagnetic fields
- 10 Polychromatic scattering by fixed and randomly changing objects
- 11 Measurement of electromagnetic energy flow
- 12 Measurement of the Stokes parameters
- 13 Description of far-field scattering in terms of actual optical observables
- 14 Electromagnetic scattering by a small random group of sparsely distributed particles
- 15 Statistically isotropic and mirror-symmetric random particles
- 16 Numerical computations and laboratory measurements of electromagnetic scattering
- 17 Far-field observables: qualitative and quantitative traits
- 18 Electromagnetic scattering by discrete random media: far field
- 19 Near-field scattering by a sparse discrete random medium: microphysical radiative transfer theory
- 20 Radiative transfer in plane-parallel particulate media
- 21 Weak localization
- 22 Epilogue
- Appendix A Dyads and dyadics
- Appendix B Free-space dyadic Green's function
- Appendix C Euler rotation angles
- Appendix D Spherical-wave decomposition of a plane wave in the far zone
- Appendix E Integration quadrature formulas
- Appendix F Wigner d-functions
- Appendix G Stationary phase evaluation of a double integral
- Appendix H Hints and answers to selected problems
- References
- Index
- Plate Section
Summary
The discussion in the preceding chapter was limited to the far field of a random particulate volume comprising a moderate number of particles. However, one is often interested in the near field in order to compute the energy budget of a volume element of a DRM rather than of the entire DRM. Furthermore, in the majority of actual applications the detector of light is located in the near zone of the entire DRM, including the cases of being inside the particulate volume. Although numerically exact solvers of the MMEs such as the MSM (Section 16.1.3) can be used to compute the near field of a DRM (see, e.g., Mackowski and Mishchenko 2013), the applicability of this direct approach is still limited in terms of the number of constituent particles and the overall size of the particulate volume relative to the wavelength.
This implies that the near-field solution of the MMEs for stochastic multi-particle objects such as those shown in Plates 1.1b—1.1f has to be based on a number of simplifying assumptions such as ergodicity, the sparsity and statistical uniformity of the particles' spatial distribution, and the asymptotic limit N → ∞, where N is the number of particles in a DRM. The main objective of the following analysis is to show that this methodology can indeed be used to derive analytically a set of closed-form equations that can be solved numerically with relative ease.
- Type
- Chapter
- Information
- Electromagnetic Scattering by Particles and Particle GroupsAn Introduction, pp. 286 - 337Publisher: Cambridge University PressPrint publication year: 2014