An Overview of Low Frequency Communications

Abstract

Use of Very Low Frequency and Low Frequency (VLF/LF, 3-300 kilohertz) electromagnetic signals for long range underwater communications predates World War II. VLF/LF communications is unique in that transmitted signals are transmitted over extremely long ranges and transmitting antennas are very large. Land-based antennas are typically designed to be supported by towers over 180 meters tall or to span mountain valleys. Airborne antennas typically measure seven kilometers long. Input powers of up to two megawatts provide detectable signals for megameters. The development of this communications system has created and exploited numerous technical advances. Propagation research, material technology, numerical analysis and scale modeling, communications performance evaluation, and modulation advances will be discussed in the context of an overview of this worldwide communications system.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1992
Accession Number
ADA262852

Entities

People

  • Kathleen Grauer
  • Therese Dougherty

Organizations

  • Naval Command, Control and Ocean Surveillance Center

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Composite Materials
  • Data Rate
  • Engineers
  • Frequency
  • Frequency Bands
  • Frequency Shift
  • Generators
  • Materials
  • Noise Generators
  • Numerical Analysis
  • Ocean Surveillance
  • Simulations
  • Simulators
  • Test And Evaluation
  • Transmitting
  • Underwater Communications
  • Very Low Frequency

Fields of Study

  • Engineering

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Optical Fiber Sensing and Electromagnetic Propagation.
  • Positioning, Navigation, and Timing (PNT) Technology.