Forward Optical Scattering from Very Rough Surfaces Near Grazing Incidence

Abstract

A series of metal and dielectric targets exhibiting fractal characteristics are produced having a range of surface roughnesses between about 1 and 16. They are all sufficiently rough that only diffuse reflection was obtained from them when illuminated with a He-Ne laser beam. The intensity scattered in the specular direction has been measured as a function of the surface roughness for near normal theta sub 20 deg and near grazing theta sub 85 deg incidence. The specular direction intensity at first falls rapidly with increasing surface roughness, but then saturates at high values of the surface roughness. Good agreement is obtained between the experimentally observed variation with surface roughness and that predicted theoretically using a fractal surface scattering models and surface parameters measured using a profile instrument. A simple graphical model is used to demonstrate qualitatively the trends observed.

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1990
Accession Number
ADA233527

Entities

People

  • D. L. Jordan

Organizations

  • Royal Signals and Radar Establishment

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Counter IED

DTIC Thesaurus Topics

  • Angle Of Incidence
  • Backscattering
  • Detection
  • Detectors
  • Diffraction
  • Electromagnetic Scattering
  • Forward Scattering
  • Frequency
  • Gaussian Distributions
  • Geometry
  • Grazing Angles
  • Measurement
  • Optical Detectors
  • Radiation
  • Scattering
  • Surface Roughness
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Mathematics or Statistics
  • Spectroscopy.

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers