MULTIWAVELENGTH LASER PROPAGATION STUDY--2

Abstract

In conducting multiwavelength scintillation experiments over a one mile path, it was found that a finite-sized transmitter aperture does not represent a true spherical-wave source, regardless of the beam divergence used. This observation has important implications for the interpretation of other data on the 'saturation' of scintillations, and in the present experiments has lead to the redesign of the transmitter to achieve a virtual point source. This has been completed, including a provision for independently increasing the aperture at each wavelength up to two inches in diameter, for later transmitter- aperture-dependence measurements. A highly-developed thermal probe system for the detailed study of turbulence structure was made completely operational, and a portable laser system was fabricated for independent 'optical turbulence strength' measurements. All subsystems of the experimental facility are operating without problems, and no further modifications are contemplated. In order to put the problem of atmospheric scintillations in current perspective and to guide the comprehensive experiments, a discussion of recent experimental and theoretical issues is given.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1970
Accession Number
AD0699498

Entities

People

  • J. R. Kerr

Organizations

  • Oregon Health & Science University

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • C4I
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Amplifiers
  • Computers
  • Dynamic Range
  • Filters
  • Frequency
  • Low Noise
  • Measurement
  • Oscillators
  • Plane Waves
  • Probability
  • Probability Distributions
  • Refractive Index
  • Resistance
  • Scattering
  • Spherical Waves
  • Statistics
  • Wave Functions

Fields of Study

  • Physics

Readers

  • Astronomy and Astrophysics.
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Software Engineering

Technology Areas

  • Directed Energy