Date of Award

12-1993

Document Type

Thesis

Degree Name

Master of Science in Electrical Engineering

Department

Department of Electrical and Computer Engineering

First Advisor

Byron M. Welsh, PhD

Abstract

The performance of an aircraft based optical system is degraded by aero-optic turbulence. The varying index of refraction within the turbulent field causes phase perturbation in an optical wave. In order to compensate for aero-optic turbulence effects, the nature of the turbulence must be understood. Large scale, organized structure within the turbulence has been found to contribute significantly to the overall phase perturbation caused by a turbulent field. A unique approach was devised to determine the turbulence structure using tomographic reconstruction techniques. Tomography provides an excellent means to determine the underlying structure within a turbulent field. The tomographic reconstruction produces a three-dimensional index of refraction plot of the turbulent field, revealing the structure within the turbulent field. An experiment was designed to determine the feasibility of the tomographic technique for reconstructing the turbulence structure. An optical wave was propagated through a turbulent field. A shearing interferometer was used to measure the wave front of the perturbed optical wave. The wave front phase map provided the projection data for a tomographic reconstruction of the index of refraction of the turbulent field. The experimental results verified the feasibility of the tomographic technique.

AFIT Designator

AFIT-GEO-ENG-93D-01

DTIC Accession Number

ADA274392

Comments

The author's Vita page is omitted.

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