A Model to Calculate EM Fields in Tropospheric Duct Environments at Frequencies through SHF.

Abstract

Non-monotonic variations of the atmospheric refractivity with height often enable energy to be propagated in a duct mode with little attenuation over long distances. A duct model employing a waveguide-mode method of analysis was developed to calculate the field strength when the refractivity variation with height, is known. The developed numerical procedure methodically determines all significant eigenmodes for elevated and surface ducts at all frequencies through SHF. Computer model results for beyond-the-horizon ducts compare favorably with measurements taken at frequencies between 65 MHz and 3.3 GHz.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1981
Accession Number
ADA107710

Entities

People

  • Sherman Marcus
  • William D. Stuart

Organizations

  • IIT Research Institute

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Communication Systems
  • Complex Numbers
  • Computational Science
  • Computer Programs
  • Coordinate Systems
  • Department Of Defense
  • Differential Equations
  • Ecology
  • Electric Fields
  • Electromagnetic Fields
  • Electromagnetic Wave Propagation
  • Electronics Laboratories
  • Line Of Sight
  • Measurement
  • Partial Differential Equations
  • Refractive Index
  • Wave Propagation

Fields of Study

  • Physics

Readers

  • Computational Modeling and Simulation
  • Radar Systems Engineering.