Compendium of the ULF/ELF Electromagnetic Fields Generated above a Sea of Finite Depth by Submerged Harmonic Dipoles

Abstract

This report extends earlier computations of the amplitudes of the quasi-static electromagnetic fields produced on and above the surface of a sea of finite depth by a submerged vertically directed harmonic magnetic dipole (VMD) to other dipoles. Specifically, it now presents data for the fields produced by a submerged vertically directed harmonic electric dipole (VED) and by submerged horizontally directed magnetic and electric dipoles (HMD and HED, respectively). The primary purpose of these computations is to determine the conditions under which an electrically conducting sea floor can produce significant changes in the fields, as compared with the fields produced on and above an infinitely deep sea, for frequencies in the ULF/ELF bands (frequencies less than 3 kHz). As in the earlier work, this report finds that even a comparatively highly conducting sea floor (conductivity of approximately 0.4S/m) can produce substantial changes in the field amplitudes for some source-receiver configurations, and, in the case of the horizontal dipoles (as previously found for the VMD), alterations of two orders of magnitude or more can occur in the amplitudes on the sea surface for smaller values of sigma f.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1980
Accession Number
ADA081952

Entities

People

  • Antony Fraser-Smith
  • D. M. Bubenik

Organizations

  • Stanford University

Tags

Communities of Interest

  • Sensors
  • Weapons Technologies

DTIC Thesaurus Topics

  • Abstracts
  • Air Force
  • Amplitude
  • California
  • Computations
  • Conductivity
  • Contracts
  • Detection
  • Electric Fields
  • Electrical Conductivity
  • Electromagnetic Fields
  • Frequency
  • Magnetic Dipoles
  • Magnetic Fields
  • Materials
  • Military Research
  • Seabed

Readers

  • Coastal Oceanography
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering