Pulse Propagation In Discrete Random Media

Abstract

In this paper we investigate the effect of multiple scattering on the propagation of electromagnetic pulses in a medium containing a random distribution of spherical scatterers. As is well known in multiple scattering theory, interferences or interactions among scatterers are important, and in some cases it is not enough to consider only first order multiple scattering which has been widely used in the study of pulse propagation in random media. As a consequence, the characteristics of scattered pulses, e.g., frequency spectrum, coherence time and coherence bandwidth, can affect the interpretation of the random medium. We examine the scattered field of a narrow band pulse wave by randomly distributed particles and show the importance of multiple scattering on estimating attenuation in the formalism. The magnitudes of the transmitted and returned pulse intensities decrease due to scattering. When a considerable amount of scatterers present in the scattering medium, the attenuation factor needs to be corrected for multiple scattering. In order to see the difference between single and multiple scattering theories on the attenuation of pulse propagation, we present two data sets in quite wide frequency ranges.