Remote Sensing Commons^™

Towards Spatial Inversion Of Aerial Gamma-Ray Survey Data For Measurement Of Naturally Occurring Radioactivity, Daniel A. Haber

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aerial gamma-ray surveying (AGRS) is used in geologic and environmental contexts to provide data on the surface spatial distribution of naturally occurring radioactive material (NORM) or other gamma-ray-emitting isotopes. The standard data reduction workflow for AGRS data involves a process whereby pointwise gamma-ray spectral data are denoised, corrected for numerous sources of background radiation and aircraft height, and are finally converted to physical values by empirical conversion factors. The reduced pointwise data are then typically spatially interpolated to form a continuous surface map.

This dissertation introduces and explores a novel spatial inversion method for reduced AGRS data that considers aircraft …

Assessment Of Vegetation Dynamics After South Sugar Loaf And Snowstorm Wildfires Using Remote Sensing Spectral Indices, Ibtihaj Ahmad

UNLV Theses, Dissertations, Professional Papers, and Capstones

Wildfires are increasingly common in sagebrush ecosystems across the western United States, leading to vegetation loss and ecosystem restructuring. This study investigated vegetation recovery within two large Nevada burn scars, the Snowstorm Fire of 2017 and the South Sugar Loaf Fire of 2018. Landsat 8 surface reflectance imagery supplied multi temporal spectral data, and vegetation burn severity was mapped with the difference Normalized Burn Ratio. The research aimed to quantify how vegetation health spectral indicators respond over time across severity gradients and to detect shifts in land cover composition from pre fire to post fire conditions.Four spectral indices—NDVI, MSI, MCARI2, …

Evaluation Of The Extent Of Floods In 2022 In Different Land Cover And Land Use Classes In Sindh Province, Pakistan Using Sentinel-1 And Sentinel-2 Imageries, Alina Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Floods are one of the most frequent and most devastating natural disasters, which cause widespread destruction and pose significant risks to human life, infrastructure, and the environment. Advancement in remote sensing technologies and methodologies have demonstrated their efficacy in disaster-related applications, such as the detection, monitoring, and analysis of floods. This study explores the utilization of Synthetic Aperture Radar (SAR) and optical imagery for flood extent mapping and studying the extent of flood over various land cover and land use classes in Pakistan's Sindh province, utilizing the cloud computing power of Google Earth Engine. The change detection method identified extensive …

Unraveling Water Quality Issues In The Colorado River Basin: Utilizing Remote Sensing Satellite Images, Statistical, And Machine Learning For Improved Monitoring, Godson Ebenezer Adjovu

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research was aimed at exploring innovative and cost-effective tools in understanding the spatiotemporal variability of water quality parameters in the Colorado River Basin (CRB), which includes the Colorado River and major reservoirs and lakes in the USA including Lake Mead. The river which arises in the state of Colorado and empties into the Republic of Mexico at the Gulf of California, is a source of water to seven US states and the Republic of Mexico and provides water to about 40 million people and million acres of farmlands in seven states in the western US and the Republic of …

Estimation Of Spatial Change In Cropland Area And Evaluation Of Irrigation Performance In Imperial Valley Using Remotely Sensed Data, Usha Poudel

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Imperial Valley (IV) in the US is an extensively irrigated agricultural region, which includes multiple crops changing on an annual and semiannual basis. The valley is facing grave concerns about water management due to its semi-arid environment, water intensive crops, and limited water supply. A simple, inexpensive, and repeatable method to detect changes in cropping patterns may assist irrigation managers to understand crop diversification and associated consumptive use. In addition, a spatial assessment of existing water irrigation system performance and productivity is crucial to benchmark and improve current water management strategies. This thesis estimates the spatial pattern of change …

Kaleidoscope Of Urban Evapotranspiration: Exploring The Science And Modeling Approaches, Rubab Saher

UNLV Theses, Dissertations, Professional Papers, and Capstones

Urban evapotranspiration is a complex physical process. It depends on various critical drivers, including the land surface temperature (LST), surface albedo, landscape types, and building orientations. All of these factors create difficulties in the estimation of evapotranspiration (ET) by changing the microclimate conditions. The literature has oversimplified microclimate conditions by considering temperature difference as the only variable defining climate. The physical process depends on land-use changes, building proximities, and landscape types. This study devised three objectives to understand the microclimate effects on ET.

In the first objective, land-use change effects on LST, surface albedo, and ET were analyzed over a …

Potential Fossil Yield Classification (Pfyc) Survey Of Nevada Surficial Geology, And A Multi-Sensor, Remote Sensing, Change-Detection Study Of Land-Use/Land-Cover Urbanization Impacting The Las Vegas Formation Located In Northwestern Las Vegas Valley, John Jayson Medema

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis is a combination of two separate but related projects. The first project is a Potential Fossil Yield Classification (PYFC) survey. The PFYC is a Bureau of Land Management funded survey designed to synthesize paleontologic information into a geographic information system (GIS) as a distributable geodatabase. The database is designed to represent surficial geologic deposits contained in a polygon shapefile. Throughout the State of Nevada each polygon represents a mapped geologic unit at a scale of at least 1:250 k. Each mapped geologic unit is then assigned a “potential fossil yield classification”, a numerical ranking value of 1-5 based …

Evaluation Of A Continuous Air Monitoring System On An Unmanned Aerial Vehicle For Measurement Of Airborne Radioactive Material, Adam Pfannenstein

UNLV Theses, Dissertations, Professional Papers, and Capstones

The release of airborne radioactive material presents a health risk hazard to many individuals, emergency responders and public. It is necessary to characterize the unknown radioactive dangers produced in the event of these incidents. Advantages to utilizing unmanned aerial systems in this effort are personnel risk reduction and quick attainment of data points in a plume. By pairing a continuous air monitor and detector with a drone, radioactive material concentration can be quantified, and thus the extent of potential doses can be estimated. A small, low-flow air sampler with a Geiger-Mueller counter was characterized using measurements of sources representing a …

Remote Sensing Of The Environmental Impacts Of Utility-Scale Solar Energy Plants, Mohammad Masih Edalat

UNLV Theses, Dissertations, Professional Papers, and Capstones

Solar energy has many environmental benefits compared with fossil fuels but solar farming can have environmental impacts especially during construction and development. Thus, in order to enhance environmental sustainability, it is imperative to understand the environmental impacts of utility-scale solar energy (USSE) plants. During recent decades, remote sensing techniques and geographic information systems have become standard techniques in environmental applications. In this study, the environmental impacts of USSE plants are investigated by analyzing changes to land surface characteristics using remote sensing. The surface characteristics studied include land cover, land surface temperature, and hydrological response whereas changes are mapped by comparing …

Predictive Modeling Of Terrestrial Radiation Exposure From Geologic Materials, Daniel A. Haber

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aerial gamma ray surveys are an important tool for national security, scientific, and industrial interests in determining locations of both anthropogenic and natural sources of radioactivity. There is a relationship between radioactivity and geology and in the past this relationship has been used to predict geology from an aerial survey. The purpose of this project

is to develop a method to predict the radiologic exposure rate of the geologic materials in an area by creating a model using geologic data, images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), geochemical data, and pre-existing low spatial resolution aerial surveys …

Modeling Background Radiation Using Geochemical Data, Kara Marsac

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aerial gamma ray surveys have many applications in geology and science in general, such as locating mining prospects, defining radioactive plumes, and detecting nuclear weapons. Unfortunately there is currently no simple way to separate the natural gamma radiation of soil and rocks from that of contaminants such as radioactive plumes. This project used geochemical data (uranium, potassium and thorium concentrations) collected from national databases, private companies, and the NURE (National Uranium Resource Evaluation) Survey, to create forward models of exposure rates measured by aerial gamma ray surveys. We developed these techniques using an area in north central Arizona known as …

Novel Deployment Of Elpasolites As A Dual Neutron / Gamma-Ray Directional Detector, Amber Lynn Guckes

UNLV Theses, Dissertations, Professional Papers, and Capstones

At a time when upholding national security has never been more important, there exists a need for the advancement of radiation detection technologies. Neutron and photon detectors are essential to fulfilling mission areas including detection and localization of missing, stolen or smuggled radiological or nuclear materials, quantification of the effects of a radiological or nuclear event, and supporting nonproliferation efforts. The aim of this study was to evaluate a new radiation detector based on the scintillation elpasolite compound Cs2LiYCl6:Ce (CLYC) for simultaneous measurements of neutron and photon flux and the localization of radiation sources. Previous studies performed on the CLYC …

Remote Sensing Based On Hyperspectral Data Analysis, Ershad Sharifahmadian

UNLV Theses, Dissertations, Professional Papers, and Capstones

In remote sensing, accurate identification of far objects, especially concealed objects is difficult. In this study, to improve object detection from a distance, the hyperspecral imaging and wideband technology are employed with the emphasis on wideband radar. As the wideband data includes a broad range of frequencies, it can reveal information about both the surface of the object and its content. Two main contributions are made in this study:

1) Developing concept of return loss for target detection: Unlike typical radar detection methods which uses radar cross section to detect an object, it is possible to enhance the process of …

Time Correlated Measurements Using Plastic Scintillators With Neutron-Photon Pulse Shape Discrimination, Norman Edison Richardson

UNLV Theses, Dissertations, Professional Papers, and Capstones

Since the beginning of the nuclear age, there has been a strong demand for the development of efficient technologies for the detection of ionizing radiation. According to the United States' Department of Energy, the accurate assessment of fissile materials is essential in achieving the nonproliferation goals of enhancing safety and security of nuclear fuel cycle and nuclear energy facilities [1]. Nuclear materials can be characterized by the measurement of prompt and delayed neutrons and gamma rays emitted in spontaneous or induced fission reactions [2] and neutrons emitted in fission reactions are the distinctive signatures of nuclear materials. Today, the most …

Temperature Trends And Urban Heat Island Intensity Mapping Of The Las Vegas Valley, Adam Leland Black

UNLV Theses, Dissertations, Professional Papers, and Capstones

Modified urban climate regions that are warmer than rural areas at night are referred to as Urban Heat Islands or UHI. Islands of warmer air over a city can be 12 degrees Celsius greater than the surrounding cooler air. The exponential growth in Las Vegas for the last two decades provides an opportunity to detect gradual temperature changes influenced by an increasing presence of urban materials. This thesis compares ground based thermometric observations and satellite based remote sensing temperature observations to identify temperature trends and UHI areas caused by urban development.

Analysis of temperature trends between 2000 and 2010 at …

The Evaluation Of Water Storage In Death Valley Using Grace Satellite Data, Maile Sweigart

UNLV Theses, Dissertations, Professional Papers, and Capstones

As drought conditions spread across the United States, concerns over water supplies, water use, and water management policies are growing and possible contributing environmental factors are continually being scrutinized. This thesis examines Death Valley as an analog for Southern Nevada and utilizes NASA EOS data, combined with ancillary climate data, to assess the effect of decadal climate variability on groundwater storage in the Death Valley area. Historical climate data, combined with satellite imagery observations, were compiled and calculated for analyses. Conclusions derived from statistical analyses infer trends between GRACE (Gravity Recovery and Climate Experiment) satellite data and fluctuating levels of …