Aperture Averaging Effects on Scintillation and the Temporal-Frequency Power Spectrum

Abstract

Aperture averaging effects on the measurement of scintillation and on the temporal-frequency power spectrum have been examined in the marine boundary surface layer using a He-Ne (6328 A) laser beam propagating over various path lengths and under varying turbulence conditions. Two significant results have been obtained: (1) For scintillation measurements, a vanishingly small receiver can best be approximated by using an aperture of diameter Dmin = (Z/k) sup (1/2) . (2) The aperture averaging correction factor for an aperture diameter D > Dmin decreases as the level of turbulence increases. Data have also been obtained supporting the theoretical prediction that an increase in aperture diameter reduces the high frequency power content of the temporal-frequency power spectrum.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1976
Accession Number
ADA030084

Entities

People

  • Howard R. Hall

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Analyzers
  • Born Approximations
  • Boundary Layer
  • Data Reduction
  • Detectors
  • Diffraction
  • Equations
  • Fresnel Zones
  • Measurement
  • Power Spectra
  • Refractive Index
  • Scattering
  • Scintillation
  • Spectra
  • Spectrum Analysis
  • Turbulence
  • Wave Equations

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Library and Information Science/ Studies, Southeast Asia Studies, Bibliography of Vietnam and Lao Studies.
  • Optical Physics and Photonics.

Technology Areas

  • Directed Energy