INTERFEROMETRIC PHASE AND AMPLITUDE FLUCTUATION MEASUREMENTS OVER A 7KM ATMOSPHERIC PATH

Abstract

A 6328 A laser interferometer of the Michelson type has a one-way path length of 7 km. The fringes are resolved by frequency-modulating the laser sufficiently to sweep over at least one fringe width. By correlation techniques, the resulting fringe intensity pattern is resolved into the true fringe crossing direction and rate and into light amplitude fluctuations. An upper limit of 300 per second is established for the former, the amplitude fluctuations being at a slower rate. With a measured intensity range of up to 5000:1, it is clear from the data that none of the currently postulated Rayleigh, log normal, or Rice distributions match the amplitude statistics over this full range. A limiting value of standard deviation for the log of the amplitude is 0.85.

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Document Details

Document Type
Technical Report
Publication Date
May 13, 1969
Accession Number
AD0692438

Entities

People

  • Ernst Gehrels

Organizations

  • Massachusetts Institute of Technology

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Amplitude Modulation
  • Atmospheric Motion
  • Computational Science
  • Computer Programs
  • Detection
  • Frequency Shift
  • Fresnel Zones
  • Interferometers
  • Laser Beams
  • Lasers
  • Measurement
  • Optical Properties
  • Probability
  • Refractive Index
  • Scattering
  • Standards
  • Wave Propagation

Fields of Study

  • Physics

Readers

  • Applied Combinatorial Optimization and Logic Circuit Design.
  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Spectroscopy.

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers