SPECTRUM ANALYSIS OF VLF EMISSIONS.

Abstract

Amplitude analysis of discrete VLF emissions using the Rayspan spectrum analyzer showed characteristics that are not readily detected using the conventional 'frequency' spectrograms. From a small sampling of discrete VLF emissions recorded at various ground stations, the following observations were made: Rise and fall times may be as small as 15 - 20 msec; Emissions that appear 'single' on a frequency spectrogram may consist of closely-linked shorter emissions, each having a duration of the order of 100 msec; Frequency modulation, previously suspected in some frequency spectrograms, is confirmed. In the samples studied the frequency of modulation ranged from 35 Hz to 70 Hz, while the frequency deviation lay mainly in the range 25 Hz to 50 Hz. (Author)

Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1968
Accession Number
AD0686088

Entities

People

  • Byung Gan Lee

Organizations

  • Stanford University

Tags

DTIC Thesaurus Topics

  • Amplitude
  • Analyzers
  • Emission
  • Frequency
  • Frequency Modulation
  • Ground Stations
  • Modulation
  • Observation
  • Sampling
  • Spectra
  • Spectrum Analysis
  • Spectrum Analyzers

Readers

  • Acoustics.
  • Astronomy and Astrophysics.
  • Spectroscopy.