Application of Volumetric Multiple-Scattering Approximations to Foliage Media
Abstract
Representation of natural terrain growth as a complex dielectric slab with some arbitrary thickness equivalent to the mean height of the vegetation is a common modeling simplification technique. The vegetation medium may be viewed as two or more different types of dielectric scatterers arranged in a random geometric configuration in a surrounding 'host' medium. Based on this assumption, the foliage is treated as a continuous medium, with the propagation of the waves governed by an effective dielectric constant, (epsilon*). In this paper several volumetric multiple-scattering models were used to determine the effective dielectric constants representative of foliage media. A brief discussion of the Average T-Matrix Approximation (ATA) and the Coherent Potential Approximation (CPA) is presented. The ATA represents the field at an individual scattering center in terms of an equivalent field produced by the other scatterers but includes no provision for the interaction between scatterers. The CPA neglects the difference between the external excitation field and the average field and includes interaction effects between scatterers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1991
- Accession Number
- ADA253337
Entities
People
- Douglas Tamasanis