Author ORCID Identifier

https://orcid.org/0009-0004-9395-2445

Date Available

6-6-2023

Year of Publication

2023

Document Type

Master's Thesis

Degree Name

Master of Science (MS)

College

Arts and Sciences

Department/School/Program

Earth and Environmental Sciences (Geology)

Advisor

William C. Haneberg

Abstract

As part of ongoing research on radionuclide mapping and radon hazard characterization, field tests were performed to evaluate the suitability and limitations of a UAV-compatible gamma spectrometer. To date, this data set includes completed stationary data collection, mobile ground collection, multi-level UAV flights over a known material transition, as well as redundant ground and multi-level UAV data collection over a relatively uniform area. Total counts were used as a measure of soil radionuclide levels for our data collected above background. Although our test sites were in regions underlain by bedrock with high indoor radon levels, uranium counts were barely above background levels. The spectrometer can delineate obvious surface material contrasts (e.g., grass versus asphalt or concrete) analogous to boundaries such as faults juxtaposing different rock units. As the height of the instrument increases above a single surface type, the sensitivity of the spectrometer decreases linearly above the ground while the on-ground footprint increases geometrically. This limits the ability to resolve geologic boundaries. In areas covered by distinctly different surface types, the variation in counts is a function of both altitude and the proportion of each surface type within the footprint of the spectrometer at that location and height. In some cases, height appears to contribute to an increase in counts if the instrument is over a low-count surface material, but the complete spectrometer footprint is dominated by a high-count surface material. Ongoing research will quantify background variability to help identify local variations in a low signal-to-noise (low gamma) environment, including the feasibility of stacking results from multiple single-height flights or profiles to cancel noise and amplify changes across geologic boundaries. Results from multi-level flights will also contribute to our understanding of instrument sensitivity and spatial resolution as functions of flying height.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2023.293

Funding Information

This research was made possible by Grant P30 ES026529 from the National Institute of Environmental Health Sciences in 2022. The Kentucky Geological Survey funded my research assistantship as a graduate researcher in the Master's of Science Thesis Program in the Earth and Environmental Science Department of the College of Arts and Sciences from 2021 to 2023. This study was also supported by the Paul Potter Internship with the Kentucky Geological Survey in 2022. The Lyman T. Johnson Fellowship helped fund this research from 2021 to 2023. In 2022 the Geological Society of America Environmental and Engineering Geology Division Graduate Poster Competition awarded funding for winning first place. The Kentucky Association of Mapping Professionals awarded the author of this research a scholarship in 2022.

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