SWEEP-FREQUENCY, SPACED-STATION MEASUREMENTS OF ROUND-THE-WORLD HF PROPAGATION.

Abstract

Spaced-station, synoptic, sweep-frequency measurements were made of hf round-the-world (RTW) propagation for a 12-month period in 1963-1964. The primary objectives were further determination of the degree of energy focusing after an RTW circulation and the azimuthal dependence of path loss. Pulse transmissions from Stanford, California, were simultaneously monitored at Stanford, Lubbock (Texas), and Pullman (Washington). RTW signals were most often received at Lubbock near winter noon and at Pullman near summer sunset, as predicted by use of simple ionospheric absorption theory. The energy was found normally to be focused in a region considerably smaller in width than 1400 km--and possibly as small as 400 km. The propagation-sector width was found to vary with time of day, frequency, and month. Typical inferred values of sector width for the system sensitivity being used were 30 deg in summer twilight and as great as 120 deg in winter midmorning. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1966
Accession Number
AD0801701

Entities

People

  • R. B. Fenwick

Organizations

  • Stanford University

Tags

DTIC Thesaurus Topics

  • Absorption
  • California
  • Frequency
  • Measurement
  • Sensitivity
  • Twilight

Readers

  • Chemistry (specifically Chemical Fluorescence)
  • Circadian Sleep-Wake Regulation and Chronobiology
  • Radar Systems Engineering.

Technology Areas

  • AI & ML
  • AI & ML - Bayesian Inference
  • Space