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Air Force Institute of Technology

2016

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Articles 151 - 180 of 193

Full-Text Articles in Engineering

Characterization Of Quad-Copter Positioning Systems And The Effect Of Pose Uncertainties On Field Probe Measurements, James C. Dossett Mar 2016

Characterization Of Quad-Copter Positioning Systems And The Effect Of Pose Uncertainties On Field Probe Measurements, James C. Dossett

Theses and Dissertations

When measuring the Radar Cross Section (RCS) of a test object, many uncertainties must be accounted for, such as the non-homogeneous nature of the medium between the radar test equipment and the platform under test. There are a variety of other error sources, including clutter and Radio Frequency Interference (RFI), motivating the development of techniques to measure and model the uncertainties in RCS measurements. The following research, in unison with prior and current efforts, intends to reduce the impact of these uncertainties by utilizing a unique two-way field probe in the form of a geodesic sphere encompassing a commercial quad-copter …


Airborne Directional Networking: Topology Control Protocol Design, Barry C. Geise Mar 2016

Airborne Directional Networking: Topology Control Protocol Design, Barry C. Geise

Theses and Dissertations

This research identifies and evaluates the impact of several architectural design choices in relation to airborne networking in contested environments related to autonomous topology control. Using simulation, we evaluate topology reconfiguration effectiveness using classical performance metrics for different point-to-point communication architectures. Our attention is focused on the design choices which have the greatest impact on reliability, scalability, and performance. In this work, we discuss the impact of several practical considerations of airborne networking in contested environments related to autonomous topology control modeling. Using simulation, we derive multiple classical performance metrics to evaluate topology reconfiguration effectiveness for different point-to-point communication architecture …


Jamming Cognitive Radios, Travis J. Freeman Mar 2016

Jamming Cognitive Radios, Travis J. Freeman

Theses and Dissertations

The goal of this thesis is to identify and evaluate weaknesses in the rendezvous process for Cognitive Radio Networks (CRNs) in the presence of a Cognitive Jammer (CJ). Jamming strategies are suggested and tested for effectiveness. Methods for safe- guarding the Cognitive Radios (CRs) against a CJ are also explored. A simulation is constructed to set up a scenario of two CRs interacting with a CJ. Analysis of the simulation is conducted primarily at the waveform level. A hardware setup is constructed to analyze the system in the physical layer, verify the interactions from the simulation, and test in a …


Dynamic Honeypot Configuration For Programmable Logic Controller Emulation, Kyle A. Girtz Mar 2016

Dynamic Honeypot Configuration For Programmable Logic Controller Emulation, Kyle A. Girtz

Theses and Dissertations

Attacks on industrial control systems and critical infrastructure are on the rise. Important systems and devices like programmable logic controllers are at risk due to outdated technology and ad hoc security measures. To mitigate the threat, honeypots are deployed to gather data on malicious intrusions and exploitation techniques. While virtual honeypots mitigate the unreasonable cost of hardware-replicated honeypots, these systems often suffer from a lack of authenticity due to proprietary hardware and network protocols. In addition, virtual honeynets utilizing a proxy to a live device suffer from performance bottlenecks and limited scalability. This research develops an enhanced, application layer emulator …


Using Phase Screens To Synthesize Electromagnetic Gaussian-Schell Model Sources With Desired Amplitude, Coherence, And Polarization, Christopher K. Kokoczka Mar 2016

Using Phase Screens To Synthesize Electromagnetic Gaussian-Schell Model Sources With Desired Amplitude, Coherence, And Polarization, Christopher K. Kokoczka

Theses and Dissertations

An electromagnetic Gaussian-Schell model (EGSM) source is built with desired coherence, amplitude, and polarization using correlated phase screens based on re- search conducted in Refs. [2, 9]. A new method of amplitude control is presented and tested using spatial light modulators (SLM). A brief review of theory and concepts is discussed followed by methods of how to build an EGSM source, correlated phase screens, and control amplitude using SLM gratings. The experimental set-up is presented which builds EGSM sources that demonstrate desired amplitude, coherence, and polarization. Irradiance correlation, degree of polarization, and Stokes parameters S0 and S1 are …


Superconducting Quantum Interference Device Array Based High Frequency Direction Finding On An Airborne Platform, Tyrel K. Kvasager Mar 2016

Superconducting Quantum Interference Device Array Based High Frequency Direction Finding On An Airborne Platform, Tyrel K. Kvasager

Theses and Dissertations

This thesis evaluates a new incredibly sensitive highly linear high dynamic range 2D Bi-SQUID array purposed by the dissertation written by Susan Berggren applied to use on an airborne platform for the purposes of HFDF. To evaluate how useful the 2D Bi-SQUID is we explore multiple signals of the same frequency in two different base sensor configurations: Non-uniform phased array and non-colocated Poynting's Theorem based vector sensors. The exploration is performed using the SPIRIT HPC system to calculate the 2D Bi-SQUID output given multiple incident signals. The AoA estimation calculation is performed using the MUSIC algorithm on the signals received …


Real-Time Implementation Of Vision-Aided Monocular Navigation For Small Fixed-Wing Unmanned Aerial Systems, Timothy I. Machin Mar 2016

Real-Time Implementation Of Vision-Aided Monocular Navigation For Small Fixed-Wing Unmanned Aerial Systems, Timothy I. Machin

Theses and Dissertations

The goal of this project was to develop and implement algorithms to demonstrate real-time positioning of a UAV using a monocular camera combined with previously collected orthorectified imagery. Unlike previous tests, this project did not utilize a full inertial navigation system (INS) for attitude, but instead had to rely on the attitude obtained by inexpensive commercial off-the-shelf (COTS) autopilots. The system consisted of primarily COTS components and open-source software, and was own over Camp Atterbury, IN for a sequence of flight tests in Fall 2015. The system obtained valid solutions over much of the flight path, identifying features in the …


Non-Linear Optimization Applied To Angle-Of-Arrival Satellite Based Geo-Localization For Biased And Time Drifting Sensors, Daniel E. Levy Mar 2016

Non-Linear Optimization Applied To Angle-Of-Arrival Satellite Based Geo-Localization For Biased And Time Drifting Sensors, Daniel E. Levy

Theses and Dissertations

Multiple sensors are used in a variety of geolocation systems. Many use Time Difference of Arrival (TDOA) or Received Signal Strength (RSS) measurements to locate the most likely location of a signal. When an object does not emit a classical RF signal, Angle of Arrival (AOA) measurements become more feasible than TDOA or RSS measurements. AOA measurements can be created from any sensor platform with any sort of camera. When location and attitude knowledge of the sensor passive objects can be tracked. A Non-Linear Optimization (NLO) method for calculating the most likely estimate from AOA measurements has been created in …


Interference Suppression Using Knowledge-Aided Subarray Pattern Synthesis, David A. New Mar 2016

Interference Suppression Using Knowledge-Aided Subarray Pattern Synthesis, David A. New

Theses and Dissertations

Most phased array systems subarray many antenna elements into far fewer digitized channels. While having more degrees of freedom (DOF) yields better performance, adding channels to create more digital DOF increases system cost and data throughput requirements. A subarray itself constitutes a phased array with as many DOF as it has antenna element weights. Typically, only one degree of freedom is used to steer the maximum gain direction of the subarray pattern. For typical antenna geometries a single subarray will provide many more spatial DOF than there are digitized channels. The inherent DOF of the subarrays could be used to …


Visual-Ins Using A Human Operator And Converted Measurements, Turner J. Montgomery Mar 2016

Visual-Ins Using A Human Operator And Converted Measurements, Turner J. Montgomery

Theses and Dissertations

A method human operated INS aiding is explored in which the pilot identifies and tracks a ground feature of unknown position over a short measurement epoch using an E/O sensor. One then refers to Visual-INS. In contrast to current research trends, a human operator is entrusted with visually tracking the ground feature. In addition, a less conventional measurement linearization technique is applied to generate “converted” measurements. A linear regression algorithm is then applied to the converted measurements providing an estimate of the INS horizontal velocity error and accelerometer biases. At the completion of the measurement epoch, the INS is corrected …


Comparison Of Methods For Radio Position Of Non-Emitting Dismounts, Collin J. Seanor Mar 2016

Comparison Of Methods For Radio Position Of Non-Emitting Dismounts, Collin J. Seanor

Theses and Dissertations

Radio Tomographic Imaging (RTI) is a form of Device Free Passive Localization (DFPL) that utilizes the Received Signal Strength (RSS) values from a collection of wireless transceivers to produce an image in order to localize a subject within a Wireless Sensor Network (WSN). Radio Mapping is another form of DFPL that can utilize the same RSS values from a WSN to localize a subject by comparing recent values to a set of calibration data. RTI and Radio Mapping have never been directly compared to one another as a means of localization within a WSN. The goal of this research is …


Multihop Rendezvous Algorithm For Frequency Hopping Cognitive Radio Networks, John A. Pavlik Mar 2016

Multihop Rendezvous Algorithm For Frequency Hopping Cognitive Radio Networks, John A. Pavlik

Theses and Dissertations

Cognitive radios allow the possibility of increasing utilization of the wireless spectrum, but because of their dynamic access nature require new techniques for establishing and joining networks, these are known as rendezvous. Existing rendezvous algorithms assume that rendezvous can be completed in a single round or hop of time. However, cognitive radio networks utilizing frequency hopping that is too fast for synchronization packets to be exchanged in a single hop require a rendezvous algorithm that supports multiple hop rendezvous. We propose the Multiple Hop (MH) rendezvous algorithm based on a pre-shared sequence of random numbers, bounded timing differences, and similar …


Electromagnetic Characterization Of Materials Using A Dual Chambered High Temperature Waveguide, Jeffrey S. Sovern Mar 2016

Electromagnetic Characterization Of Materials Using A Dual Chambered High Temperature Waveguide, Jeffrey S. Sovern

Theses and Dissertations

Measurement of the electromagnetic properties of materials at high temperatures is important for industrial, scientific, medical, and aerospace applications [1]. Current high-temperature electromagnetic material characterization is a time consuming process that typically requires three days to collect data from one material specimen. For example, the standard high-temperature process involving rectangular waveguides [2] requires measurements of the sample (1), the empty waveguide (2), and a metal short standard (3) completed in separate heated runs over three days to perform the Nicolson-Ross-Weir inversion algorithm for computing permittivity and permeability. The technique developed here will reduce the high-temperature measurement process from three days …


A Comparative Analysis Of Ieee 802.15.4 Adapters For Wireless Range Finding, Andrew P. Seitz Mar 2016

A Comparative Analysis Of Ieee 802.15.4 Adapters For Wireless Range Finding, Andrew P. Seitz

Theses and Dissertations

ZigBee wireless networks have become increasingly prevalent over the past decade. Based on the IEEE 802.15.4 low data rate wireless standard, ZigBee offers low-cost mesh connectivity in hospitals, refineries, building automation, and critical infrastructure. This thesis explores two ZigBee Received Signal Strength Indicator (RSSI)-based rangefinding tool sets used for assessing wireless network security: Z-Ranger and Zbfind. Z-Ranger is a new tool set developed herein for the Microchip Zena Wireless Adapter that offers configurable distance estimating parameters and a RSSI resolution of 256 values. Zbfind is an application developed for the Atmel RZUSBstick with no configurable distance estimating parameters and a …


Field-Based Phase Retrieval Using Under-Sampled Data, Tatsuki L. Watts Mar 2016

Field-Based Phase Retrieval Using Under-Sampled Data, Tatsuki L. Watts

Theses and Dissertations

A phase retrieval algorithm designed for use with under-sampled astronomical data is developed in this thesis. Blind-deconvolution, Gerchberg Saxton (GS), and a field-based compass search are combined into an algorithm capable of recovering Zernike coefficients 4 through 11 from single frames of noisy, under-sampled data without the need to unwrap the recovered phase. The performance of the algorithm in data under-sampled by a factor of 2 is compared the performance of the algorithm on Nyquist-sampled data. In simulation trials, the magnitudes of all 8 estimated Zernike coefficients converged to within half a wave of the true values for 98% of …


Comparison Of Radio Frequency Distinct Native Attribute And Matched Filtering Techniques For Device Discrimination And Operation Identification, Barron D. Stone Mar 2016

Comparison Of Radio Frequency Distinct Native Attribute And Matched Filtering Techniques For Device Discrimination And Operation Identification, Barron D. Stone

Theses and Dissertations

The research presented here provides a comparison of classification, verification, and computational time for three techniques used to analyze Unintentional Radio- Frequency (RF) Emissions (URE) from semiconductor devices for the purposes of device discrimination and operation identification. URE from ten MSP430F5529 16-bit microcontrollers were analyzed using: 1) RF Distinct Native Attribute (RFDNA) fingerprints paired with Multiple Discriminant Analysis/Maximum Likelihood (MDA/ML) classification, 2) RF-DNA fingerprints paired with Generalized Relevance Learning Vector Quantized-Improved (GRLVQI) classification, and 3) Time Domain (TD) signals paired with matched filtering. These techniques were considered for potential applications to detect counterfeit/Trojan hardware infiltrating supply chains and to defend …


Neutron Versus Gamma Radiation Effects On Ytterbium-Doped Optical Fibers, Olivia M. Borman Mar 2016

Neutron Versus Gamma Radiation Effects On Ytterbium-Doped Optical Fibers, Olivia M. Borman

Theses and Dissertations

Multimode ytterbium-doped optical fibers (YDFs) are increasingly utilized in military applications involving fiber lasers and amplifiers. YDFs were irradiated with three different radiation sources (neutron, gamma, and mixed gamma/neutron) in order to determine the independent effects that gamma and neutron radiation have on the fibers. The transmission spectra of the fibers were measured during each irradiation and the spectral shapes and attenuation were compared at similar doses. Comparisons of the spectra showed that gamma radiation results in increased attenuation over the 550-975 nm wavelengths. Fast neutrons were found to contribute to increased attenuation near 500 nm. Neutron radiation also caused …


Nuclear Forensics Applications Of Principal Component Analysis On Micro X-Ray Fluorescence Images, Sarah T. Castro Mar 2016

Nuclear Forensics Applications Of Principal Component Analysis On Micro X-Ray Fluorescence Images, Sarah T. Castro

Theses and Dissertations

A method is developed for rapid detection and analysis of actinides and correlated materials in nuclear fallout debris using principal component analysis on quantified micro x-ray fluorescence intensity values. This method is then applied to address goals of nuclear forensics. The first implementation is a collaborative effort with the National Institute of Standards and Technology and the Federal Bureau of Investigation Laboratory to produce a standard reference material that is a surrogate for glassy nuclear fallout debris in a modern urban environment. This reference material will enable researchers in the development and validation of nuclear forensics methods. A method for …


Radiation Effects In Thin Film Hexagonal Boron Nitride, Nathaniel M. Kaminski Mar 2016

Radiation Effects In Thin Film Hexagonal Boron Nitride, Nathaniel M. Kaminski

Theses and Dissertations

The radiation response of 2 nm and 12 nm hexagonal boron nitride (hBN) thin film insulators was studied using metal insulator semiconductor (MIS) devices. Current-voltage, capacitance-voltage, and impedance spectroscopy measurements were compared to quantify changes in hBN resistance due to radiation damage. MIS devices exposed to a gamma total dose deposition of 3.1 Mrad(Si) from a Co- 60 source exhibited a small increase in hBN resistance and no observable C-V shift associated with charge trapping. MIS devices irradiated with 4.5 MeV silicon ions showed no significant resistivity decrease to a threshold fluence of 1 ×1012 for the 2 nm …


Characterization Of 2d Jammed Granular Memristive Copper Arrays, Len L. Kedrow Mar 2016

Characterization Of 2d Jammed Granular Memristive Copper Arrays, Len L. Kedrow

Theses and Dissertations

A novel sensor made of jammed granular memristive copper spheres was explored in an effort to develop a protection technology that could be used in non-proliferation treaty monitoring. The micro-copper spheres were annealed for various times at a constant temperature. SEM, EDS, and XPS were used to characterize the growth of the oxide coating. Electrical characterization of the device was done by confining the granular copper spheres to a two-dimensional plane using a unique test fixture capable of measuring I-V curves at the boundary of the circuit board using tungsten pillar electrodes. Electroforming of the copper spheres produced soft dielectric …


Analysis Of Neutron Effects For Asteroid Disruption, Aaron J. Ferguson Mar 2016

Analysis Of Neutron Effects For Asteroid Disruption, Aaron J. Ferguson

Theses and Dissertations

The use of nuclear weapons is one possible method for disrupting or deflecting an asteroid on a trajectory to impact the earth. A largely unexplored component of weapon yield in a disruption scenario is the impact of the neutron output. The results of MCNP-6 simulations are presented demonstrating the effect that incident neutron energy has on the total energy deposited in an asteroid, including that the efficiency of energy deposition in a material is inversely proportional to the incident neutron energy due to negative Q-value reactions. The effects of material composition on the total energy deposited as well as the …


Optically Stimulated Luminescence From Ag-Doped Lithium Tetraborate (Li2b4o7), Ember S. Maniego Mar 2016

Optically Stimulated Luminescence From Ag-Doped Lithium Tetraborate (Li2b4o7), Ember S. Maniego

Theses and Dissertations

Silver-doped lithium tetraborate (Li2B4O7) crystals emit optically stimulated luminescence (OSL) in response to stimulating light around 400 nm. Photoluminescence, optical absorption, and electron paramagnetic resonance (EPR) were used to identify the defects in the crystal that cause this OSL. Lithium tetraborate crystals have Ag+ ions at Li+ sites and at interstitial sites. Upon ionization at room temperature via x rays, electron-hole pairs are generated. The electrons are trapped at Ag+ occupying interstitial sites, while the holes are trapped at Ag+ at lithium sites. The trapped electron centers become Ag0 …


Improved Performance By The Tie-Gcm With The Inclusion Of Helium As A Major Species, Fredrick R. Schmidt Mar 2016

Improved Performance By The Tie-Gcm With The Inclusion Of Helium As A Major Species, Fredrick R. Schmidt

Theses and Dissertations

When considering the neutral constituents in the upper thermosphere and exosphere, helium needs to be accounted for as a major species. As detailed by Emmert [2015], most first-principle models do not consider helium a major species when solving for diffusion and collisions within the atmosphere. First-principle, physics-based models hold a distinct advantage of seasonal variations and spatial resolution over empirical models which leads to a more realistic depiction of the atmosphere. The National Center for Atmospheric Research’s (NCAR) self-consistent, physics-based Thermosphere-Ionosphere-Electrodynamic General Circulation Model (TIE-GCM) has been updated to take into account this neutral constituent in its calculations. The major …


Material And Design Considerations For A Portable Ultra-Violet (Uv) Light Emitting Diode (Led) Water Purification Device, Drew D. Gallucci Mar 2016

Material And Design Considerations For A Portable Ultra-Violet (Uv) Light Emitting Diode (Led) Water Purification Device, Drew D. Gallucci

Theses and Dissertations

Department of Defense personnel often deploy to austere environments where clean water is not readily available. Ultraviolet (UV) radiation through the use of light emitting diodes (LEDs) in a portable device offers a potential method for expedient water treatment. This research studied the application of one diode, low power, UV LEDs and nine diode, high power, UV LEDs within a portable steel reactor and Teflon reactors of three different wall thicknesses. Reactor efficiency was determined through measuring and comparing the rate constants for Advanced Oxidation of hydrogen peroxide with yellow tartrazine as a witness dye. Experiments conducted with low power …


Unmanned Aerial Vehicle (Uav) Operators’ Workload Reduction: The Effect Of 3d Audio On Operators’ Workload And Performance During Multi-Aircraft Control, Sungbin Kim Mar 2016

Unmanned Aerial Vehicle (Uav) Operators’ Workload Reduction: The Effect Of 3d Audio On Operators’ Workload And Performance During Multi-Aircraft Control, Sungbin Kim

Theses and Dissertations

The importance and number of Unmanned Aerial Vehicle (UAV) operations are rapidly growing in both military and civilian applications. This growth has produced significant manpower issues, producing a desire that multiple aircraft are controlled by a single operator as opposed to the current model where one aircraft may require multiple operators. A potential issue is the need for an operator to monitor radio traffic for the call signs of multi-aircraft. An investigation of the use of 3D sound was undertaken to investigate whether an automatic parser, which preselected the spatial location of relevant versus irrelevant call signs, could aid UAV …


Multi-Trajectory Automatic Ground Collision Avoidance System With Flight Tests (Project Have Escape), John V. Trombetta Mar 2016

Multi-Trajectory Automatic Ground Collision Avoidance System With Flight Tests (Project Have Escape), John V. Trombetta

Theses and Dissertations

Multi-trajectory automatic collision avoidance techniques for heavy-type aircraft are explored to increase aviation safety procedures and decrease losses due to controlled flight into terrain. Additionally, this research includes flight test results from the United States Test Pilot School’s Test Management Project (TMP) titled Have Emergency Safe Calculated Autonomous Preplanned Exit (ESCAPE). Currently, the heavy aircraft community lacks an automatic collision avoidance system that has proven to save lives in fighter-type aircraft. The tested algorithm includes both a 3-path and a 5-path avoidance technique that is compared to an optimal solution which minimizes aircraft control to avoid terrain. The research utilizes …


Implementation And Performance Of Factorized Backprojection On Low-Cost Commercial-Off-The-Shelf Hardware, Alec C. Rasmussen Mar 2016

Implementation And Performance Of Factorized Backprojection On Low-Cost Commercial-Off-The-Shelf Hardware, Alec C. Rasmussen

Theses and Dissertations

Traditional Synthetic Aperture Radar (SAR) systems are large, complex, and expensive platforms that require significant resources to operate. The size and cost of the platforms limits the potential uses of SAR to strategic level intelligence gathering or large budget research efforts. The purpose of this thesis is to implement the factorized backprojection SAR image processing algorithm in the C++ programming language and test the code's performance on a low cost, low size, weight, and power (SWAP) computer: a Raspberry Pi Model B. For a comparison of performance, a baseline implementation of filtered backprojection is adapted to C++ from pre-existing MATLAB® …


An Openeaagles Framework Extension For Hardware-In-The-Loop Swarm Simulation, Derek B. Worth Mar 2016

An Openeaagles Framework Extension For Hardware-In-The-Loop Swarm Simulation, Derek B. Worth

Theses and Dissertations

Unmanned Aerial Vehicle (UAV) swarm applications, algorithms, and control strategies have experienced steady growth and development over the past 15 years. Yet, to this day, most swarm development efforts have gone untested and thus unimplemented. Cost of aircraft systems, government imposed airspace restrictions, and the lack of adequate modeling and simulation tools are some of the major inhibitors to successful swarm implementation. This thesis examines how the OpenEaagles simulation framework can be extended to bridge this gap. This research aims to utilize Hardware-in-the-Loop (HIL) simulation to provide developers a functional capability to develop and test the behaviors of scalable and …


A Practical Wireless Exploitation Framework For Z-Wave Networks, Joseph L. Hall Mar 2016

A Practical Wireless Exploitation Framework For Z-Wave Networks, Joseph L. Hall

Theses and Dissertations

Wireless Sensor Networks (WSN) are a growing subset of the emerging Internet of Things (IoT). WSNs reduce the cost of deployment over wired alternatives; consequently, use is increasing in home automation, critical infrastructure, smart metering, and security solutions. Few published works evaluate the security of proprietary WSN protocols due to the lack of low-cost and effective research tools. One such protocol is ITU-T G.9959-based Z-Wave, which maintains wide acceptance within the IoT market. This research utilizes an open source toolset, presented herein, called EZ-Wave to identify methods for exploiting Z-Wave devices and networks using Software-Defined Radios (SDR). Herein, techniques enabling …


Modeling And Economy’S Dynamics And External Influences Through A System Of Differential Equations, Thomas M. Dickey Mar 2016

Modeling And Economy’S Dynamics And External Influences Through A System Of Differential Equations, Thomas M. Dickey

Theses and Dissertations

This research proposes a methodology to develop models for the greater understanding of the application of the economic instrument of national power through a selection of factors that define the economic condition of a country. The major components of an economy are identified as GDP per capita, a treasury bond yield, and a major stock market index. The components have interconnected dynamics along with external influences from the United Stated Federal Funds Rate and foreign direct investment. These connections are considered through a metamodel in the form of a system of differential equations which is solved as an inverse problem. …