Electromagnetic Scattering From a Strongly Turbulent Medium

A wave incident on a volume of random fluctuations of dielectric permittivity will be scattered in all directions. When the fluctuation is weak, the single scattering theory is widely used and found to be satisfactory; however, as many practical situations are known to exist, if fluctuations are strong, the multiple scattering effect must be taken into account. In this report, two theoretical models of the multiple scattering effects are presented and discussed. The average scattered intensity is the quantity of greatest concern and is computed for both models. In the first model, the cumulative forward-scatter single-backscatter assumption is used. Under this assumption, the wave is scattered mainly in a narrow cone centered in the forward direction. A scattering cross-section formula cast in the form of the Booker-Gordon formula is derived. This formula takes into account both the cumulative forward scattering and the Fresnel diffraction. This result is further generalized to cover the case of multiple random layers. In the second model, the equation for the two-frequency two-position mutual coherence function is derived, based on the wave equation as a starting point. The equation is in the form of the radiative transfer equation. The incoherent part of this function corresponds to the scattered intensity in the backward direction in case a plane wave is impressed.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Yang, Chih-Chung

• Engineering, Electronics and Electrical

Identifier

(UMI)AAI8502350

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/69297