Accession Number : ADP006376

Title :   A Model for Bistatic Scattering of Electromagnetic Waves from Foliage Covered Rough Terrain,

Corporate Author : ROME LAB HANSCOM AFB MA

Personal Author(s) : Papa, Robert J. ; Tamasanis, Douglas T.

Report Date : SEP 1991

Pagination or Media Count : 12

Abstract : The problem of determining the electromagnetic (EM) power received by an antenna located over foliage covered rough terrain in a bistatic scattering geometry is important and quite complex. A model has been developed which can quantitatively determine the effect of a foliage layer on EM waves scattered from rough terrain. The theoretical approximations obtained from this model are compared with data at two levels; the loss in penetrating the foliage and the total normalized scattering cross section. In the model, a transmitting antenna and receiving antenna are located at arbitrary heights and locations over a surface with two scales of roughness covered by a foliage layer. Both the coherent and incoherent power scattered into the receiver are calculated. It is assumed that the foliage is sufficiently sparse that the coherent field is dominant over the incoherently scattered waves within the medium. The propagation of the coherent field in the foliage is characterized by an 'effective' complex dielectric constant. Explicit expressions for have been determined from several multiple scattering formalisms and are based on the dielectric properties of the scattering elements comprising the foliage, i.e. wood, leaves, blades of grass.

Descriptors :   *FOLIAGE, *ELECTROMAGNETIC WAVE PROPAGATION, *ELECTROMAGNETIC SCATTERING, *BISTATIC DETECTION, *RADAR ANTENNAS, ANTENNAS, BLADES, CONSTANTS, CROSS SECTIONS, DIELECTRIC PROPERTIES, DIELECTRICS, GEOMETRY, LAYERS, MODELS, POWER, RECEIVERS, ROUGHNESS, SCATTERING, SCATTERING CROSS SECTIONS, TERRAIN, TRANSMITTING, WAVES, WOOD, VEGETATION, TARGET DETECTION, MILITARY EQUIPMENT.

Subject Categories : Radiofrequency Wave Propagation
      Active & Passive Radar Detection & Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE