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Air Force Institute of Technology

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Counter Weapon Control, Brian J. Roadruck Mar 2015

Counter Weapon Control, Brian J. Roadruck

Theses and Dissertations

In this work, pursuit-evasion differential game theory is applied to the target defense scenario. The targets, attackers, and the defenders positional information is assumed to be known to the players. With positional information, a computational efficient method of strategy synthesis can be derived applying a differential game theory approach. We demonstrate that when non-optimal strategies are employed by one of the players, e.g. Line Of Sight guidance, the outcome will favor the players that employ the optimal strategy given by the solution of the pursuit-evasion differential game.

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The Use Of Ultra-Violet (Uv) Light Emitting Diodes (Leds) In An Advanced Oxidation Process (Aop) With Brilliant Blue Fcf As An Indicator, Robert W. Scott Iv Mar 2015

The Use Of Ultra-Violet (Uv) Light Emitting Diodes (Leds) In An Advanced Oxidation Process (Aop) With Brilliant Blue Fcf As An Indicator, Robert W. Scott Iv

Theses and Dissertations

Water contamination can result from terrorist acts, industrial accidents, or natural phenomena. Advanced Oxidation Processes (AOPs) represent a potentially useful method for water decontamination. This research explored the application of Brilliant Blue FCF as a witness dye in an Advanced Oxidation Process (AOP) employing Ultra-Violet (UV) Light Emitting Diodes (LEDs) with peroxide (H2O2). In addition to exploring the attributes of Brilliant Blue FCF within this application, this research employed this dye to evaluate the effect of varied UV LED duty cycles (pulsing) on the reaction rates of a UV/H2O2 AOP. Experiments performed using …

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Army Information Technology Procurement: A Business Process Analysis, Alexander M. Vukcevic Mar 2015

Army Information Technology Procurement: A Business Process Analysis, Alexander M. Vukcevic

Theses and Dissertations

This thesis presents a business process analysis of the Army's ICT procurement system. The research identified several inefficiencies and proposes several potential solutions. the contributions of this research include a unified taxonomy, a method to prioritize requests, and system architecture products for development of an automated and sustainable collaboration interface for the CIO/G6 to streamline their IT acquisition process. Development of a centralized system would reduce waste in the request process from submission to formal accounting, hasten the movement of requests between stakeholders, maintain a digital signature authorization for each approval authority, provide a reporting database to recognize reprogramming thresholds, …

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Error Characterization Of Flight Trajectories Reconstructed Using Structure From Motion, Daniel C. Alix Mar 2015

Error Characterization Of Flight Trajectories Reconstructed Using Structure From Motion, Daniel C. Alix

Theses and Dissertations

This research effort assessed the accuracy of Structure from Motion (SFM) algorithms in replicating aircraft fight trajectories. Structure from Motion techniques can be used to estimate aircraft trajectory by determining the position and pose of an aircraft mounted camera from a sequential series of images taken during flight. An algorithm is proposed and implemented that successfully reconstructed aircraft trajectory using only a known starting position and a sequential series of images. The error in and reliability of the algorithm was found to be a function of image resolution as well as the amount of overlap and angular separation between sequential …

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Navigation Constellation Design Using A Multi-Objective Genetic Algorithm, Heather C. Diniz Mar 2015

Navigation Constellation Design Using A Multi-Objective Genetic Algorithm, Heather C. Diniz

Theses and Dissertations

In satellite constellation design, performance and cost of the system drive the design process. The Global Positioning System (GPS) constellation is currently used to provide positioning and timing worldwide. As satellite technology has improved over the years, the cost to develop and maintain the satellites has increased. Using a constellation design tool, it is possible to analyze the tradeoffs of new navigation constellation designs (Pareto fronts) that illustrate the tradeoffs between position dilution of precision (PDOP) and system cost. This thesis utilized Satellite Tool Kit (STK) to calculate PDOP values of navigation constellations, and the Unmanned Spacecraft Cost Model (USCM) …

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Optimized Flight Path For Localization Using Line Of Bearing, Namkyu Kim Mar 2015

Optimized Flight Path For Localization Using Line Of Bearing, Namkyu Kim

Theses and Dissertations

This research develops optimized flight paths for localization of a target using LOB measurements. The target area is expressed as an error ellipse using the measurement errors of the LOBs. The optimization approach is focused on minimizing the size of the error ellipse. The algorithm for the optimized path is generated and compared with typical flight paths. The optimization routine is based on the results revised from previous similar research in the literature. A geometrical method to estimate the error ellipse is combined with optimal control in this research. Each LOB gives a possible target area and this target area …

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Reflections Of A Wave: An Analysis Of Photonic Doppler Velocimetry Systems, Brian K. Lagrange Mar 2015

Reflections Of A Wave: An Analysis Of Photonic Doppler Velocimetry Systems, Brian K. Lagrange

Theses and Dissertations

Munitions are one of the Air Force's most effective weapons in eliminating targets, but also one of the most expensive. Due to the inherent high-cost in deploying munitions, munition shock wave detonation must be better observed and quantified for munitions to be more cost-efficient. PDV systems have the potential to achieve this quantification of shock wave properties on a molecular scale during solid-against-solid impacts. The overall goal of this research was to determine whether the current photonic Doppler velocimetry (PDV) system at Eglin Air Force Base is prepared for future explosive sensitivity testing. This determination was done through an uncertainty …

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Computer Modeling Of A Rotating Detonation Engine In A Rocket Configuration, Nihar Shah Mar 2015

Computer Modeling Of A Rotating Detonation Engine In A Rocket Configuration, Nihar Shah

Theses and Dissertations

Detonation-based combustors leverage the higher thermodynamic efficiency of the Atkinson cycle compared to the traditional deflagration-based combustion of the Brayton cycle. The rotating detonation engine (RDE) has one or more shock waves rotating around an annulus. The RDE can theoretically be 20% more thermally efficient than a traditional deflagration-based cycle. A RDE was modeled in Numerical Propulsion System Simulation (NPSS) based on a model developed in Microsoft Excel. The thermodynamic analysis of the RDE in these models is broken into four streams. Empirical models were used to find the percentage of the total flow in each stream. The pre-detonation pressure …

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Characterization And Modeling Of A Control Moment Gyroscope, Dylan R. Penn Mar 2015

Characterization And Modeling Of A Control Moment Gyroscope, Dylan R. Penn

Theses and Dissertations

The Air Force Research Laboratory (AFRL) is developing a spacecraft simulator that uses Control Moment Gyroscopes (CMGs). Prior to the research herein, the Air Force Institute of Technology (AFIT) designed and built six laboratory-rated CMGs for use on the AFRL spacecraft simulator. The main contributions of this research are in the testing and modeling of a single CMG. Designing, building, and operating spacecraft simulators is time consuming and expensive, but less so than tests with on-orbit spacecraft. Reductions in cost and schedule can be realized by investing in modeling the spacecraft simulator and payload before testing. A model of the …

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Optimal Recovery Trajectories For Automatic Ground Collision Avoidance Systems (Auto Gcas), Angela W. Suplisson Mar 2015

Optimal Recovery Trajectories For Automatic Ground Collision Avoidance Systems (Auto Gcas), Angela W. Suplisson

Theses and Dissertations

The USAF's F-16 Automatic Ground Collision Avoidance System (Auto GCAS) uses a single pre-planned roll to wings- level and 5-g pull-up to meet the operational requirements of being both aggressive and timely, meaning that extremely agile avoidance maneuvers will be executed at the last second to avoid the ground. There currently exists no similar Auto GCAS for manned military heavy' aircraft with lower climb performance such as transport, tanker, or bomber aircraft. This research proposes a new optimal control approach to the ground collision avoidance problem for heavy aircraft by mapping the aggressive and timely requirements of the automatic recovery …

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Experimental Magnetohydrodynamic Energy Extraction From A Pulsed Detonation, Kaz I. Teope Mar 2015

Experimental Magnetohydrodynamic Energy Extraction From A Pulsed Detonation, Kaz I. Teope

Theses and Dissertations

The high MWatt power available in a fuel-fed detonation wave, which contains combustion ions in the trailing gas, provides an opportunity for external power extraction via electromagnetically forced charged particle drift. Sets of experiments were accomplished using a pulsed detonation tube, extracting power across a load resistor in an electrical circuit with an applied electric or magnetic field to determine what magnitude of gas conductivity and power extraction could be attained from an unseeded or seeded pulsed detonation driven combustion. Due to the low magnetic field strength, even with flow seeding, the power extracted in this research was not enough …

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Design And Test Of An Attitude Determination And Control System For A 6u Cubesat Using Afit's Cubesat Testbed, Michael L. Tibbs Mar 2015

Design And Test Of An Attitude Determination And Control System For A 6u Cubesat Using Afit's Cubesat Testbed, Michael L. Tibbs

Theses and Dissertations

The design and test of a 6U CubeSat Attitude Determination and Control System (ADCS) are explored to establish single-axis control using AFIT's CubeSat testbed consisting of a Helmholtz cage and hemi-spherical air bearing. The Helmholtz cage produces a near-uniform magnetic field inside the cage while the air bearing provides a near-frictionless surface for ADCS testing. The ADCS testbed includes a four wheel pyramid reaction wheel array (RWA) for actuation and an inertial measurement unit (IMU) for attitude determination. Along with the ADCS hardware, the ADCS testbed also includes an Electrical Power System (EPS) and Command and Data Handling (CDH) for …

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Simulation Of Locking Space Truss Deployments For A Large Deployable Sparse Aperture Reflector, Dylan M. Van Dyne Mar 2015

Simulation Of Locking Space Truss Deployments For A Large Deployable Sparse Aperture Reflector, Dylan M. Van Dyne

Theses and Dissertations

Large deployable space structures require an inordinate amount of effort to fully design and test on Earth. To aid in the determination of the feasibility of the reflector, a method to simulate the structure's deployment was developed using COMSOL. The simulation model is comprised of a locking hinge truss that constitutes the partial reflector structure. To meet computational and temporal restrictions, the structure is simplified to use simple beams with square cross sections and is meshed to a sufficient accuracy with second order elements. The geometry is modeled in the truss's stowed configuration, with the connecting hinges and applied forces …

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Advancements Of In-Flight Mass Moment Of Inertia And Structural Deflection Algorithms For Satellite Attitude Simulators, Jonathan W. Wright Mar 2015

Advancements Of In-Flight Mass Moment Of Inertia And Structural Deflection Algorithms For Satellite Attitude Simulators, Jonathan W. Wright

Theses and Dissertations

Experimental satellite attitude simulators have been used to test and analyze control algorithms; driving down risk before implementation on operational satellites. Ideally, the dynamic response of a terrestrial-based experimental satellite attitude simulator matches that of an on-orbit satellite. Unfortunately, gravitational disturbance torques and poorly characterized moments of inertia introduce uncertainty into the system dynamics leading to questionable experimental results. This research consists of three distinct, but related contributions to the field of developing robust satellite attitude simulators. First, existing approaches to estimate mass moments and products of inertia are evaluated followed by a proposition and evaluation of a new approach …

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Absorption Spectroscopy Of Rubidium In An Alkali Metal Dispenser Cell And Bleached Wave Analysis, James M. Rosenthal Mar 2015

Absorption Spectroscopy Of Rubidium In An Alkali Metal Dispenser Cell And Bleached Wave Analysis, James M. Rosenthal

Theses and Dissertations

An absorption spectrum of a rubidium alkali metal dispenser (AMD) cell was obtained in order to determine the system s suitability for use in a diode pumped alkali laser (DPAL) and use in high-temperature spectroscopic studies. The AMD produced a concentration of 3.65 0.16 1010 cm-3, which is in the ideal range for Beer s Law region absorption spectroscopy, but too low to make a high-power DPAL in a 10 cm cell with a poor Q resonator. Before AMDs can be used to determine pressure broadening and shifting coefficients, issues concerning contamination and producing rubidium vapor at …

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Non-Rated Air Force Line Officer Attrition Rates Using Survival Analysis, Jill A. Schofield Mar 2015

Non-Rated Air Force Line Officer Attrition Rates Using Survival Analysis, Jill A. Schofield

Theses and Dissertations

The Air Force structures its workforce around rank structure and work specialty codes (Air Force Specialty Codes (AFSCs)). The challenge is to grow and manage personnel to fill a variety of skill sets at a variety of ranks over a 20-30 year planning horizon. To ensure that the missions are accomplished while adhering to congressionally-mandated force allocations, the Air Force is continually attempting to \right size its force by maintaining the correct balance of personnel in each career field. The Air Force conducts its force structure management responsibility by comparing historical attrition rates to current manpower requirements for each AFSC …

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2014 Annual Report Of The Graduate School Of Engineering And Management, Air Force Institute Of Technology, Office Of Research And Sponsored Programs, Graduate School Of Engineering And Management, Afit Mar 2015

2014 Annual Report Of The Graduate School Of Engineering And Management, Air Force Institute Of Technology, Office Of Research And Sponsored Programs, Graduate School Of Engineering And Management, Afit

AFIT Documents

The Graduate School's Annual Report highlights research focus areas, new academic programs, faculty accomplishments and news, and provides top-level sponsor-funded research data and information.

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Distributed Kernelized Locality-Sensitive Hashing For Faster Image Based Navigation, Scott A. Hutchison Mar 2015

Distributed Kernelized Locality-Sensitive Hashing For Faster Image Based Navigation, Scott A. Hutchison

Theses and Dissertations

Content based image retrieval (CBIR) remains one of the most heavily researched areas in computer vision. Different image retrieval techniques and algorithms have been implemented and used in localization research, object recognition applications, and commercially by companies such as Facebook, Google, and Yahoo!. Current methods for image retrieval become problematic when implemented on image datasets that can easily reach billions of images. In order to process extremely large datasets, the computation must be distributed across a cluster of machines using software such as Apache Hadoop. There are many different algorithms for conducting content based image retrieval, but this research focuses …

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Verification And Validation Of Monte Carlo N-Particle 6 For Computing Gamma Protection Factors, William J. Erwin Mar 2015

Verification And Validation Of Monte Carlo N-Particle 6 For Computing Gamma Protection Factors, William J. Erwin

Theses and Dissertations

This thesis examined the suitability of a particle simulator known as "Monte Carlo n-Particle 6" (MCNP6) to determine how well U.S. Army vehicles shield their occupants from gamma radiation. MCNP6 compared favorably to three alternate modeling approaches and another particle simulator. In a validation experiment, MCNP6 was found to produce a gamma protection factor within 5% of the experimental result with 95% confidence. Further evaluations validated MCNP6's ability to produce reliable results with simplified or approximated inputs, model different sources, and position those sources in different shielding geometries. MCNP6 is suitable for evaluating gamma protection of Army vehicles and further …

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Con-Resistant Trust For Improved Reliability In A Smart Grid Special Protection System, Crystal M. Shipman, Kenneth M. Hopkinson, Juan L. Lopez Jr. Feb 2015

Con-Resistant Trust For Improved Reliability In A Smart Grid Special Protection System, Crystal M. Shipman, Kenneth M. Hopkinson, Juan L. Lopez Jr.

Faculty Publications

This paper applies a con-resistant trust mechanism to improve the performance of a communications-based special protection system to enhance its effectiveness and resiliency. Smart grids incorporate modern information technologies to increase reliability and efficiency through better situational awareness. However, with the benefits of this new technology come the added risks associated with threats and vulnerabilities to the technology and to the critical infrastructure it supports. The research in this paper uses con-resistant trust to quickly identify malicious or malfunctioning (untrustworthy) protection system nodes to mitigate instabilities. The con-resistant trust mechanism allows protection system nodes to make trust assessments based on …

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Assessing Predictive Ability Of Three Auroral Precipitation Models Using Dmsp Energy Flux, Cory T. Lane, Ariel O. Acebal, Yihua Zheng Feb 2015

Assessing Predictive Ability Of Three Auroral Precipitation Models Using Dmsp Energy Flux, Cory T. Lane, Ariel O. Acebal, Yihua Zheng

Faculty Publications

Our study statistically compares the total energy flux outputs of Newell et al.'s (2010a) oval variation, assessment, tracking, intensity, and online nowcasting (OVATION) Prime model, Hardy et al.'s (1991) Kp‐based model, and a coupled Space Weather Modeling Framework ring current model to energy flux data obtained from 2198 Defense Meteorological Satellite Program (DMSP) satellite passes in the Northern Hemisphere. Our DMSP data set includes 28 days grouped into continuous 3 and 4 day periods between 2000 and 2008 and encompasses magnetic local times (MLTs) between 04:00 and 21:00. We obtain the most equatorward magnetic latitude coordinate, where a DMSP satellite …

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Theoretical Investigation Of Stabilities And Optical Properties Of Si12C12 Clusters, Xiaofeng F. Duan, Larry W. Burggraf Jan 2015

Theoretical Investigation Of Stabilities And Optical Properties Of Si12C12 Clusters, Xiaofeng F. Duan, Larry W. Burggraf

Faculty Publications

By sorting through hundreds of globally stable Si12C12 isomers using a potential surface search and using simulated annealing, we have identified low-energy structures. Unlike isomers knit together by Si–C bonds, the lowest energy isomers have segregated carbon and silicon regions that maximize stronger C–C bonding. Positing that charge separation between the carbon and silicon regions would produce interesting optical absorption in these cluster molecules, we used time-dependent density functional theory to compare the calculated optical properties of four isomers representing structural classes having different types of silicon and carbon segregation regions. Absorptions involving charge transfer between segregated …

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Two-Dimensional Temperature Analysis Of Nuclear Fireballs Using Digitized Film, Robert C. Slaughter, Tyler R. Peery, John W. Mcclory Jan 2015

Two-Dimensional Temperature Analysis Of Nuclear Fireballs Using Digitized Film, Robert C. Slaughter, Tyler R. Peery, John W. Mcclory

Faculty Publications

Researchers at Lawrence Livermore National Laboratory have begun digitizing technical films spanning the atmospheric nuclear testing operations conducted by the United States from 1945 through 1962. Each atmospheric nuclear test was filmed by Edgerton, Germeshausen, and Grier, Inc., using between 20 to 40 cameras per test. These technical film test data represent a primary source for advancing the knowledge of nuclear weapon output as well as the understanding of nonnuclear high-temperature gases. This manuscript outlines the procedures followed in order to perform two-dimensional temperature calculations for early time nuclear fireballs using digitized film. The digitized optical densities of the film …

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Graduate School Of Engineering And Management Catalog 2015-2017, Graduate School Of Engineering And Management, Air Force Institute Of Technology Jan 2015

Graduate School Of Engineering And Management Catalog 2015-2017, Graduate School Of Engineering And Management, Air Force Institute Of Technology

AFIT Documents

The Graduate Catalog represents the offerings, programs, and requirements in effect at the time of publication.

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Reconfigurable Solid-State Dye-Doped Polymer Ring Resonator Lasers, Hengky Chandrahalim, Xudong Fan Jan 2015

Reconfigurable Solid-State Dye-Doped Polymer Ring Resonator Lasers, Hengky Chandrahalim, Xudong Fan

Faculty Publications

This paper presents wavelength configurable on-chip solid-state ring lasers fabricated by a single-mask standard lithography. The single- and coupled-ring resonator hosts were fabricated on a fused-silica wafer and filled with 3,3′-Diethyloxacarbocyanine iodide (CY3), Rhodamine 6G (R6G) and 3,3′-Diethylthiadicarbocyanine iodide (CY5)-doped polymer as the reconfigurable gain media. The recorded lasing threshold was ~220 nJ/mm2 per pulse for the single-ring resonator laser with R6G, marking the lowest threshold shown by solid-state dye-doped polymer lasers fabricated with a standard lithography process on a chip. A single-mode lasing from a coupled-ring resonator system with the lasing threshold of ~360 nJ/mm2 per pulse …

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Monolithic Optofluidic Ring Resonator Lasers Created By Femtosecond Laser Nanofabrication, Hengky Chandrahalim, Qiushu Chen, Ali A. Said, Mark Dugan, Xudong Fan Jan 2015

Monolithic Optofluidic Ring Resonator Lasers Created By Femtosecond Laser Nanofabrication, Hengky Chandrahalim, Qiushu Chen, Ali A. Said, Mark Dugan, Xudong Fan

Faculty Publications

We designed, fabricated, and characterized a monolithically integrated optofluidic ring resonator laser that is mechanically, thermally, and chemically robust. The entire device, including the ring resonator channel and sample delivery microfluidics, was created in a block of fused-silica glass using a 3-dimensional femtosecond laser writing process. The gain medium, composed of Rhodamine 6G (R6G) dissolved in quinoline, was flowed through the ring resonator. Lasing was achieved at a pump threshold of approximately 15 μJ/mm2. Detailed analysis shows that the Q-factor of the optofluidic ring resonator is 3.3 × 104, which is limited by both solvent …

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Taming The Hurricane Of Acquisition Cost Growth – Or At Least Predicting It, Allen J. Deneve, Erin T. Ryan, Jonathan D. Ritschel, Christine M. Schubert Kabban Jan 2015

Taming The Hurricane Of Acquisition Cost Growth – Or At Least Predicting It, Allen J. Deneve, Erin T. Ryan, Jonathan D. Ritschel, Christine M. Schubert Kabban

Faculty Publications

Cost growth is a persistent adversary to efficient budgeting in the Department of Defense. Despite myriad studies to uncover causes of this cost growth, few of the proposed remedies have made a meaningful impact. A key reason may be that DoD cost estimates are formulated using the highly unrealistic assumption that a program’s current baseline characteristics will not change in the future. Using a weather forecasting analogy, the authors demonstrate how a statistical approach may be used to account for these inevitable baseline changes and identify related cost growth trends. These trends are then used to reduce the error in …

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Sulfur Vacancies In Photorefractive Sn2P2S6 Crystals, Eric M. Golden, Sergey A. Basun, A. A. Grabar, I. M. Stoika, Nancy C. Giles, D. R. Evans, Larry E. Halliburton Dec 2014

Sulfur Vacancies In Photorefractive Sn2P2S6 Crystals, Eric M. Golden, Sergey A. Basun, A. A. Grabar, I. M. Stoika, Nancy C. Giles, D. R. Evans, Larry E. Halliburton

Faculty Publications

A photoinduced electron paramagnetic resonance (EPR) spectrum in single crystals of Sn2P2S6 (SPS) is assigned to an electron trapped at a sulfur vacancy. These vacancies are unintentionally present in undoped SPS crystals and are expected to play an important role in the photorefractive behavior of the material. Nonparamagnetic sulfur vacancies are formed during the initial growth of the crystal. Subsequent illumination below 100 K with 442 nm laser light easily converts these vacancies to EPR-active defects. The resulting S = 1/2 spectrum shows well-resolved and nearly isotropic hyperfine interactions with two P ions and two Sn ions. Partially resolved interactions …

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Multi-Objective Trajectory Optimization Of A Hypersonic Reconnaissance Vehicle With Temperature Constraints, Tadeusz J. Masternak Dec 2014

Multi-Objective Trajectory Optimization Of A Hypersonic Reconnaissance Vehicle With Temperature Constraints, Tadeusz J. Masternak

Theses and Dissertations

Temperature-constrained optimal trajectories for a scramjet-based hypersonic reconnaissance vehicle were generated by developing an optimal control formulation and solving it using a variable order Gauss-Radau quadrature collocation method. The vehicle was assumed to be an air-breathing reconnaissance aircraft that has specified takeoff/landing locations, airborne refueling constraints, specified no-fly zones, and specified targets for sensor data collections. The aircraft model included fight dynamics, aerodynamics, and thermal constraints. This model was incorporated into an optimal control formulation that includes constraints on both the vehicle as well as mission parameters, such as avoidance of no-fly zones and coverage of high-value targets. Optimal trajectories …

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Cloud-Induced Uncertainty For Visual Navigation, Alyssa N. Gutierrez Dec 2014

Cloud-Induced Uncertainty For Visual Navigation, Alyssa N. Gutierrez

Theses and Dissertations

This research addresses the numerical distortion of features due to the presence of clouds in an image. The research aims to quantify the probability of a mismatch between two features in a single image, which will describe the likelihood that a visual navigation system incorrectly tracks a feature throughout an image sequence, leading to position miscalculations. First, an algorithm is developed for calculating transparency of clouds in images at the pixel level. The algorithm determines transparency based on the distance between each pixel color and the average pixel color of the clouds. The algorithm is used to create a dataset …

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