NEAR FIELDS AND ANTIPODAL FIELDS IN THE TERRESTRIAL EARTH-TO-IONOSPHERE WAVE GUIDE.

Abstract

Near fields of a vertical electric dipole are expressed as a series of zonal harmonics or as a summation of wave-guide modes. These representations are compared with dipole fields on a conducting ground plane and with field calculations using the method of images or ray theory. The series of zonal harmonics and the mode sum provide nearly identical near fields; their difference characterizes the contribution of so-called branch-cut waves and is negligible in the present computational model. In the near field range, the method of images gives the simplest field representation for ELF; for VLF, a useful approximation is provided by combining the ground wave and a single sky wave. At the upper wave-guide boundary, the radial electric fields are finite; but the other field components vanish when approaching the source axis. The field components exhibit similar variations also when approaching the antipode of the source. (Author)

Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1968
Accession Number
AD0679164

Entities

People

  • Janis Galejs

Organizations

  • Sylvania Electric Products

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Boundaries
  • Electric Fields
  • Electromagnetic Radiation
  • Harmonics
  • Ionosphere
  • Near Field
  • Radiation
  • Sky Waves

Fields of Study

  • Physics

Readers

  • Astronomy and Astrophysics.
  • Calculus or Mathematical Analysis
  • Plasma Physics / Magnetohydrodynamics