VLF/LF/MF Whispering Gallery Propagation Studies.

Abstract

The propagation of very low frequency (VLF) and low frequency (LF) radio waves in the earth-ionosphere waveguide is affected profoundly by the earth's curvature. In particular, for frequencies greater than about 20 kHz, some modes are possible for which the energy is concentrated near the base of the ionosphere and the field strength near the ground is small. It is useful to think of such modes as being composed of waves repeatedly reflected at the inside surface of the ionosphere. Using analogy with sound waves, we can call these modes whispering-gallery modes. Since they depend only very slightly on ground conductivity, these modes are also referred to as earth-detached modes. The Navy currently is pursuing efforts leading to a feasibility demonstration of a balloon gateway communications system that would employ a balloon-to-balloon cross link based on the whispering-gallery propagation modes. This report discusses some recent whispering-gallery theoretical advances and simplifications. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Sep 09, 1981
Accession Number
ADA106517

Entities

People

  • Peter R. Bannister

Organizations

  • Naval Underwater Systems Center

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies
  • Ground and Sea Platforms
  • Materials and Manufacturing Processes
  • Weapons Technologies

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Altitude
  • Computer Simulations
  • Electromagnetic Wave Propagation
  • Electrons
  • Environment
  • Frequency
  • Geography
  • High Altitude
  • Ionosphere
  • Phase Velocity
  • Physics
  • Physics Laboratories
  • Radio Frequency
  • Radio Waves
  • Simulations
  • Very Low Frequency

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Space/Atmospheric Physics.
  • Wave Propagation and Nonlinear Chaotic Dynamics.