Date of Award

3-9-2009

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Engineering Physics

First Advisor

Michael A. Marciniak, PhD

Abstract

Optical devices interrogated with a laser in the appropriate band can exhibit strong, deterministic reflections of the incident beam. This characteristic could be exploited for optical target detection and identification. The distribution of reflected power is strongly dependent on the geometry of the interrogation scenario, atmospheric conditions, and the cross section of the target optical device. Previous work on laser interrogation systems in this area has focused on analytic models or testing. To the best of my knowledge, I am presenting for the first time an approach to predict reflected power for a variety of interrogation configurations, targets, and propagation conditions using numeric simulation based on wave optics. Numeric simulation has a cost advantage over laboratory and field experiments and avoids the limiting complexity of analytic models. Moreover, results demonstrate that reflected power can be predicted within error with an appropriately characterized. Simulations were prepared in MATLAB and run for interrogation scenarios using a simple retroreflector (corner cube) and a surrogate complex optical system (lens-mirror) target. Laboratory and field experiments were conducted for simulation validation in the absence and presence of atmospheric turbulence with a focus on bistatic receiver configurations. Two interrogation wavelengths, 1064nm and 4636nm, were used. Targets used in this experiment were modeled in simulation by measuring or estimating their deviation from a perfectly flat reflector and applying the corresponding Zernike mode phase aberrations to the simulated pupil. Strengths and limitations of the simulation environment are addressed.

AFIT Designator

AFIT-GEO-ENP-09-M03

DTIC Accession Number

ADA495727

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