Digital Commons Network^™

Radar Based Navigation In Unknown Terrain, Kyle J. Kauffman

Theses and Dissertations

There is a great need to develop non-GPS based methods for positioning and navigation in situations where GPS is not available. This research focuses on the development of an Ultra-Wideband Orthogonal Frequency Division Multiplexed (UWB-OFDM) radar as a navigation sensor in GPS-denied environments. A side-looking vehicle-fixed UWB-OFDM radar is mounted to a ground or aerial vehicle continuously collecting data. A set of signal processing algorithms and methods are developed which use the raw radar data to aide in calculating the vehicle position and velocity via a simultaneous localization and mapping (SLAM) approach. The radar processing algorithms detect strong, persistent, and …

A Nonparametric Approach To Segmentation Of Ladar Images, Eric A. Buschelman

Theses and Dissertations

The advent of advanced laser radar (ladar) systems that record full-waveform signal data has inspired numerous inquisitions which aspire to extract additional, previously unavailable, information about the illuminated scene from the collected data. The quality of the information, however, is often related to the limitations of the ladar camera used to collect the data. This research project uses full-waveform analysis of ladar signals, and basic principles of optics, to propose a new formulation for an accepted signal model. A new waveform model taking into account backscatter reflectance is the key to overcoming specific deficiencies of the ladar camera at hand, …

Exploitation Of Rf-Dna For Device Classification And Verification Using Grlvqi Processing, Donald R. Reising

Theses and Dissertations

This dissertation introduces a GRLVQI classifier into an RF-DNA fingerprinting process and demonstrates applicability for device classification and ID verification. Unlike MDA/ML processing, GRLVQI provides a measure of feature relevance that enables Dimensional Reduction Analysis (DRA) to enhance the experimental-to-operational transition potential of RF-DNA fingerprinting. Using 2D Gabor Transform RF-DNA fingerprints extracted from experimentally collected OFDM-based 802.16 WiMAX and 802.11 WiFi device emissions, average GRLVQI classification accuracy of %C greater than or equal to 90% is achieved using full and reduced dimensional feature sets at SNR greater than or equal to 10.0 dB and SNR greater than or equal to …

Passive Ranging Using A Dispersive Spectrometer And Optical Filters, Jacob A. Martin

Theses and Dissertations

Monocular passive ranging using atmospheric oxygen absorption has been demonstrated in the past using an FTS. These instruments are very sensitive to vibration making them di cult to use on an airborne platform. This work focuses on whether passive ranging can be done with instruments that are easier to deploy. Two potential instruments are tested and compared: a diffraction grating spectrometer and optical filters. A grating spectrometer was able to estimate range to within 5% for a static solid rocket motor ring at a distance of 910 m using the NIR absorption band of oxygen. Testing at shorter ranges produced …

Modeling The Effects Of The Local Environment On A Received Gnss Signal, Marshall E. Haker

Theses and Dissertations

There is an ongoing need in the GNSS community for the development of high-fidelity simulators which generate data that replicates what can truly be expected from a challenging environment such as an urban canyon or an indoor environment. The algorithm developed for use in the research in this dissertation, the Signal Decomposition and Parameterization Algorithm (SDPA), is presented in order to respond to this need. This algorithm is designed to decompose a signal received using a GNSS recording and playback system and output parameters that can be used to reconstruct the effects on the signal of the environment local to …

The Role Of Customer Engagement In Innovation Adoption, Scott A. Skiple

Theses and Dissertations

Full knowledge of a customer's true unmet need should improve the likelihood of providing that customer with an Option that meets the need. Since there is inherent risk in making any change, that customer will be more likely to accept the risk they more they understand the option. Both the customer and the solution provider possess knowledge that the other needs, knowledge which is often highly contextual and difficult to transfer, and thus a sufficiently close relationship between the customer and the solution provider should improve this knowledge transfer. It is, however, exceedingly difficult to measure this relationship, or the …

Epr And Endor Studies Of Point Defects In Lithium Tetraborate Crystals, Douglas A. Buchanan

Theses and Dissertations

Lithium tetraborate (Li2B4O7 or LTB) is a promising material for both radiation dosimetry and neutron detection applications. LTB crystals can be grown pure or doped with different impurities including transition-metal and rare-earth ions. Research in this dissertation focuses on undoped LTB crystals and LTB crystals doped with copper and silver. Electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) are used to characterize point defects in the lithium tetraborate crystals. Thermoluminescence (TL), photoluminescence (PL), photoluminescence excitation (PLE), and optical absorption (OA) are also used. An intrinsic hole trap associated with lithium vacancies is characterized with EPR and ENDOR and its …

The Effects Of Observations And Maneuvers On Orbit Solutions, Christine M. Schudrowitz

Theses and Dissertations

The purpose of this research is to characterize the performance of the optimal sequential filter used in ODTK with a maneuvering satellite. Specifically, this thesis sought to characterize the performance using two scenarios: performance with a maneuver in between passes and performance with a limited number of measurements. The performance of the filter is evaluated by analyzing the covariance values generated during the orbit estimation process. Larger covariance values signify reduced performance of the filter. Several variables for the maneuvering satellite are used, including the maneuver direction and the maneuver magnitude. The time of the maneuver is also varied, which …

Design And Characterization Of Optical Metamaterials Using Tunable Polarimetric Scatterometry, Jason C. Vap

Theses and Dissertations

Optical metamaterials are a class of engineered materials with a wide range of material properties and an equally wide range of anticipated applications. This research targets optical metamaterials in two ways. First, the dimensional constraints necessary to bring effective medium theory (EMT) into agreement with the already well-established transfer matrix method (TMM) modeling for a periodic, stratified (metal-dielectric) near-zero permittivity structure were determined. This provided a path to leverage the use of EMT in the design of near-zero permittivity structures and accurately predict its post-fabrication behavior. Second, the first tunable infrared (IR) Mueller matrix polarimeter-scatterometer was developed to capture the …

Parametrizing Finite Frames And Optimal Frame Completions, Miriam J. Poteet

Theses and Dissertations

Frames are used in many signal processing applications. We consider the problem of constructing every frame whose frame operator has a given spectrum and whose vectors have prescribed lengths. For a given spectrum and set of lengths, we know when such a frame exists by the Schur-Horn Theorem; it exists if and only if its spectrum majorizes its squared lengths. We provide a more constructive proof of Horn's original result. This proof is based on a new method for constructing any and all frames whose frame operator has a prescribed spectrum and whose vectors have prescribed lengths. Constructing all such …

Predicting The Wear Of High Speed Rocket Sleds, Lauren B. Wuertemberger

Theses and Dissertations

Holloman Air Force Base houses the 10 mile long Holloman High Speed Test Track (HHSTT) in New Mexico and can run hypersonic experiments at speeds up to 10,000m/s. Tested objects are loaded onto sleds, which are connected to the track by slippers that slide along the rails. The payload sled is propelled down the track by a series of rocket sleds. The ability to predict the wear that will occur on the slippers during these experiments is important for slipper design and preventing catastrophic failure. However, high speeds complicate wear prediction as there additional contributing factors, including inconsistent surface contact, …

Minimization Of Collateral Damage In Airdrops And Airstrikes, Steven P. Dillenburger

Theses and Dissertations

Collateral damage presents a significant risk during air drops and airstrikes, risking citizens' lives and property, straining the relationship between the United States Air Force and host nations. This dissertation presents a methodology to determine the optimal location for making supply airdrops in order to minimize collateral damage while maintaining a high likelihood of successful recovery. A series of non-linear optimization algorithms is presented along with their relative success in finding the optimal location in the airdrop problem. Additionally, we present a quick algorithm for accurately creating the Pareto frontier in the multi-objective airstrike problem. We demonstrate the effect of …

Effect Of Accessory Power Take-Off Variation On A Turbofan Engine Performance, Anis Faidi

Theses and Dissertations

Engine fuel efficiency of aerospace vehicles can be reached by different techniques. One way to do that is to reduce aircraft subsystems power supply effects on the engine performance. Previous research work has showed that extracting bleed air from the high pressure compressor exit is more efficient than extracting the equivalent amount of energy from the low pressure spool shaft. A high bypass turbofan engine was modeled using the Numerical Propulsion System Simulation (NPSS). The baseline engine performance was evaluated at different flight conditions of Mach number and altitude. To better understand the effect of air bleed take-off and shaft …

Investigation Of Diode Pumped Alkali Laser Atmospheric Transmission Using Tunable Diode Laser Absorption Spectroscopy, Christopher A. Rice

Theses and Dissertations

A field deployable, tunable diode laser absorption spectroscopy (TDLAS) device fiber coupled to a pair of 12.5" Ritchey-Chretien telescopes was used to study atmospheric propagation for open path lengths of 100 m to 1,000 m to estimate atmospheric transmission at key High Energy Laser (HEL) wavelengths. The potassium (K) version of the Diode Pumped Alkali Laser (DPAL) operates in between two of the sharp oxygen rotational features in the PP and the PQ branches. Initial experiments were performed in the vicinity of molecular oxygen X3Σ-g to b1Σ+g electronic transition lines near the potassium emission line at 770 nm. More than …

Scaling Study Of Wave Rotor Turbo-Normalization Of A Small Internal Combustion Engine, Brandon D. Smith

Theses and Dissertations

One issue facing small Remotely Piloted Aircraft engines is their ability to maintain performance at altitude. Since many of these aircraft use commercial off the shelf engines originally designed for radio controlled aircraft and lawn care implements, the reduced pressure environment significantly degrades the operability of the engine as the altitude increases. An option to overcome this difficulty is to supercharge the system; however most superchargers are designed for larger, typically automotive, engines. As a supercharger's size is decreased, there are large efficiency losses. Therefore, there is a need to accomplish this function on a smaller scale without. One option …

Resolution Study Of A Hyperspectral Sensor Using Computed Tomography In The Process Of Noise, Samuel V. Mantravadi

Theses and Dissertations

Recently, a new type of hyperspectral imaging sensor has been proposed which simultaneously records both spectral data and multiple spatial dimensions. Unlike dispersive imaging spectrometers, chromo-tomographic hyperspectral imaging sensors (CTHIS) record two spatial dimensions as well as a spectral dimension using computed tomography (CT) techniques with only a finite number of spatially-spectrally diverse images. To date, the factors affecting resolution of these sensors have not been examined. This research examines factors affecting resolution, specifically the number of the focus planes needed to resolve a particular object calculated from a theoretical lower bound, determine a method of reconstructing a hyperspectral object …

Exploring The Dynamics And Modeling National Budget As A Supply Chain System: A Proposal For Reengineering The Budgeting Process And For Developing A Management Flight Simulator, Christoforos Kalloniatis

Theses and Dissertations

In the Science of Economics, there has been a debate about the optimal fiscal and budgetary policy that should be implemented by governments. On the one side, the advocates of the Keynesian Theory assert that in recession times governments should run budgets with deficits, in order to stimulate the economy, while the supporters of the Balanced Budget Theory, on the contrary, underscores the need to reduce and even eliminate the budget deficits. However, previous experience shows that both theories often failed to accomplish their goals, because they underestimated a very sensitive parameter: national budgets are not just an estimate of …

Quantifying Performance Bias In Label Fusion, Alexander M. Venzin

Theses and Dissertations

Classification systems are employed to remotely assess whether an element of interest falls into a target class or non-target class. These systems have uses in fields as far ranging as biostatistics to search engine keyword analysis. The performance of the system is often summarized as a trade-off between the proportions of elements correctly labeled as target plotted against the number of elements incorrectly labeled as target. These are empirical estimates of the true positive and false positive rates. These rates are often plotted to create a receiver operating characteristic (ROC) curve that acts as a visual tool to assess classification …

Investigation Into Suitability Of Geopolymers (Illite & Metakaolin) For The Space Environment, Brandon T. Cesul

Theses and Dissertations

Suitability of non-organic polymers for space application is studied. Materials included are illite and metakaolin. Bulk material suitability was investigated for exposure to ultraviolet radiation, atomic oxygen, and high energy charged particles. Outgassing phenomenon of the materials was studied. Curing shrinkage reduction techniques were identified as well.

Novel Discretization Schemes For The Numerical Simulation Of Membrane Dynamics, Kyle F. Kolsti

Theses and Dissertations

Motivated by the demands of simulating flapping wings of Micro Air Vehicles, novel numerical methods were developed and evaluated for the dynamic simulation of membranes. For linear membranes, a mixed-form time-continuous Galerkin method was employed using trilinear space-time elements, and the entire space-time domain was discretized and solved simultaneously. For geometrically nonlinear membranes, the model incorporated two new schemes that were independently developed and evaluated. Time marching was performed using quintic Hermite polynomials uniquely determined by end-point jerk constraints. The single-step, implicit scheme was significantly more accurate than the most common Newmark schemes. For a simple harmonic oscillator, the scheme …

Intelligent Behavioral Action Aiding For Improved Autonomous Image Navigation, Kwee Guan Eng

Theses and Dissertations

In egomotion image navigation, errors are common especially when traversing areas with few landmarks. Since image navigation is often used as a passive navigation technique in Global Positioning System (GPS) denied environments; egomotion accuracy is important for precise navigation in these challenging environments. One of the causes of egomotion errors is inaccurate landmark distance measurements, e.g., sensor noise. This research determines a landmark location egomotion error model that quantifies the effects of landmark locations on egomotion value uncertainty and errors. The error model accounts for increases in landmark uncertainty due to landmark distance and image centrality. A robot then uses …

Passive Synthetic Aperture Radar Imaging Using Commercial Ofdm Communication Networks, Jose R. Gutierrez Del Arroyo

Theses and Dissertations

Modern communication systems provide myriad opportunities for passive radar applications. OFDM is a popular waveform used widely in wireless communication networks today. Understanding the structure of these networks becomes critical in future passive radar systems design and concept development. This research develops collection and signal processing models to produce passive SAR ground images using OFDM communication networks. The OFDM-based WiMAX network is selected as a relevant example and is evaluated as a viable source for radar ground imaging. The monostatic and bistatic phase history models for OFDM are derived and validated with experimental single dimensional data. An airborne passive collection …

Utilizing Graphics Processing Units For Network Anomaly Detection, Jonathan D. Hersack

Theses and Dissertations

This research explores the benefits of using commonly-available graphics processing units (GPUs) to perform classification of network traffic using supervised machine learning algorithms. Two full factorial experiments are conducted using a NVIDIA GeForce GTX 280 graphics card. The goal of the first experiment is to create a baseline for the relative performance of the CPU and GPU implementations of artificial neural network (ANN) and support vector machine (SVM) detection methods under varying loads. The goal of the second experiment is to determine the optimal ensemble configuration for classifying processed packet payloads using the GPU anomaly detector. The GPU ANN achieves …

Effects Of Architecture On Information Leakage Of A Hardware Advanced Encryption Standard Implementation, Eric A. Koziel

Theses and Dissertations

Side-channel analysis (SCA) is a threat to many modern cryptosystems. Many countermeasures exist, but are costly to implement and still do not provide complete protection against SCA. A plausible alternative is to design the cryptosystem using architectures that are known to leak little information about the cryptosystem's operations. This research uses several common primitive architectures for the Advanced Encryption Standard (AES) and assesses the susceptibility of the full AES system to side-channel attack for various primitive configurations. A combined encryption/decryption core is also evaluated to determine if variation of high-level architectures affects leakage characteristics. These different configurations are evaluated under …

Creating Network Attack Priority Lists By Analyzing Email Traffic Using Predefined Profiles, Eric J. Merrit

Theses and Dissertations

Networks can be vast and complicated entities consisting of both servers and workstations that contain information sought by attackers. Searching for specific data in a large network can be a time consuming process. Vast amounts of data either passes through or is stored by various servers on the network. However, intermediate work products are often kept solely on workstations. Potential high value targets can be passively identified by comparing user email traffic against predefined profiles. This method provides a potentially smaller footprint on target systems, less human interaction, and increased efficiency of attackers. Collecting user email traffic and comparing each …

Ground Vehicle Navigation Using Magnetic Field Variation, Jeremiah A. Shockley

Theses and Dissertations

The Earth's magnetic field has been the bedrock of navigation for centuries. The latest research highlights the uniqueness of magnetic field measurements based on position due to large scale variations as well as localized perturbations. These observable changes in the Earth's magnetic field as a function of position provide distinct information which can be used for navigation. This dissertation describes ground vehicle navigation exploiting variation in Earth's magnetic field using a self-contained navigation system consisting of only a magnetometer and magnetic field maps. In order to achieve navigation, effective calibration enables repeatable magnetic field measurements from different vehicles and facilitates …

Towards The Mitigation Of Correlation Effects In The Analysis Of Hyperspectral Imagery With Extension To Robust Parameter Design, Jason P. Williams

Theses and Dissertations

Standard anomaly detectors and classifiers assume data to be uncorrelated and homogeneous, which is not inherent in Hyperspectral Imagery (HSI). To address the detection difficulty, a new method termed Iterative Linear RX (ILRX) uses a line of pixels which shows an advantage over RX, in that it mitigates some of the effects of correlation due to spatial proximity; while the iterative adaptation from Iterative Linear RX (IRX) simultaneously eliminates outliers. In this research, the application of classification algorithms using anomaly detectors to remove potential anomalies from mean vector and covariance matrix estimates and addressing non-homogeneity through cluster analysis, both of …

Individual Resistance To Change, Jeffrey C. Sandusky

Theses and Dissertations

This thesis examines individual resistance to change and concludes that it is a constantly evolving process with many contributing factors. Defining resistance to change is a challenge within its own right. To account for the actions involved in change resistance is an even more complex undertaking. In this research, resistance to change is examined and explained using the influences of goals, participation, leadership effectiveness, and communication. These factors are expressed as the composition of what makes an individual resist or accept a change. Each of the four elements of resistance to change are examined independently and then synthesized into a …

A Study Of Executable Model Based Systems Engineering From Dodaf Using Simulink, Weston J. Hanoka, Michael H. Ryan

Theses and Dissertations

Diagrams and visuals often cannot adequately capture a complex system’s architecture for analysis. The Department of Defense Architectural Framework (DoDAF), written to follow the Unified Modeling Language (UML), is a collection of mandated common architectural products for interoperability among the DoD components. In this study, DoDAF products from as-is Remotely Piloted Aircraft (RPA) Satellite Communication (SATCOM) systems have been utilized for the creation of executable architectures as part of an Executable Model Based Systems Engineering (EMBSE) process. EMBSE was achieved using Simulink, a software tool for modeling, simulating and analyzing dynamic systems.

This study has demonstrated that DoDAF products can …

Operationally Responsive Spacecraft Using Electric Propulsion, Thomas C. Co

Theses and Dissertations

A desirable space asset is responsive and flexible to mission requirements, low-cost, and easy to acquire. Highly-efficient electric thrusters have been considered a viable technology to provide these characteristics; however, it has been plagued by limitations and challenges such that operational implementation has been severely limited. The technology is constantly improving, but even with current electric propulsion, a spacecraft is capable of maneuvering consistently and repeatedly in low-Earth orbit to provide a responsive and flexible system. This research develops the necessary algorithm and tools to demonstrate that EP systems can maneuver significantly in a timely fashion to overfly any target …