Date of Award

3-2020

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Engineering Physics

First Advisor

Jack McCrae, PhD

Abstract

Previous turbulence measurements along a near-ground, 500 m, horizontal path using two helium-neon laser beacons and Hartmann Turbulence Sensor (HTS) yielded profiles of C2n by measuring local aberrated wavefront tilts. The HTS C2n estimates were consistent with integrated turbulence values collected along the same path by a BLS900 scintillometer. Further validation of the HTS profiling method is necessary to produce accurate optical turbulence profiles for wavefront correction and to eventually gain an improved understanding of turbulence in the lower atmosphere and its variation as a function of altitude. In order to add confidence to the HTS dual-beacon profiling method, a collection of sonic anemometers was added along the path to collect point measurements of C2T, which were used to derive values of C2n. Propagation over a non-homogeneous path (i.e. part grass and part concrete) ensured the turbulence profile along thepath is more varied. C2n profiles in this work derived from HTS data captured on 25 and 26 July 2019 agreed strongly with the collocated anemometer and BLS measurements.

AFIT Designator

AFIT-ENP-MS-20-M-082

DTIC Accession Number

AD1107615

Comments

This thesis received the 2020 AFIT Chancellor's Award.

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