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2016

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Articles 6031 - 6060 of 9607

Full-Text Articles in Engineering

Application Of Non-Rated Line Officer Attrition Levels And Career Field Stability, Christine L. Zens Mar 2016

Application Of Non-Rated Line Officer Attrition Levels And Career Field Stability, Christine L. Zens

Theses and Dissertations

The Air Force monitors the strength of its active duty officer force and attempts to achieve the difficult challenge of employing a diversity of talent among career specialties and experience levels. This study completes two objectives, predicting future manning levels for 23 career fields, and providing a statistical framework to assess the stability of these fields. The first part of the study applies regression and survival analysis to subpopulations within the active duty Air Force officer corps, and then aggregates them by year to forecast future personnel levels. Four career fields are considered, including Acquisitions (ACQ), Logistics (LOG), Support (SPT), …

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Modeling The Components Of An Economy As A Complex Adaptive System, Richard J. Mickelsen Mar 2016

Modeling The Components Of An Economy As A Complex Adaptive System, Richard J. Mickelsen

Theses and Dissertations

Complex systems science is a relatively new discipline and has not been widely applied to the field of economics. Much of current economic theory relies on principles of constrained optimization and often fails to see economic variables as part of an interconnected network. While tools for forecasting economic indicators are based primarily on autoregressive techniques, these techniques are not always well-suited to predicting the future performance of highly volatile data sets such as the stock market. This research portrays the stock market as one component of a networked system of economic variables, with the federal funds rate acting as an …

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Rate Setting Analysis: A Statistical Approach To Outlier Analysis In The Rate Setting Process Within The United States Transportation Command, Warren B. Mcgriff Mar 2016

Rate Setting Analysis: A Statistical Approach To Outlier Analysis In The Rate Setting Process Within The United States Transportation Command, Warren B. Mcgriff

Theses and Dissertations

The rate setting process implemented by the USTRANSCOM J8 Program Analysis & Financial Management Directorate (USTC J8 or TCJ8) is of importance, as accurate rates yield proper and equitable recoupment of costs from customers and ensure USTC can achieve an accurate Net Operating Result (NOR) in each given year. This research sought to identify areas in which the current rate setting methodology can be improved. We initially examined the use of six months of historical cost data versus a full year of data to set rates, concluding that there is not a statistically significant difference with respect to their relative …

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Long-Term Impacts Of Military Drawdown On The Industrial Base, Anton H. Martyn Mar 2016

Long-Term Impacts Of Military Drawdown On The Industrial Base, Anton H. Martyn

Theses and Dissertations

Since World War II, competition in the defense industry has fallen by over 90 percent. Over half of contracts currently executed by the United States Navy and Air Force are awarded without any competition. With the recent defense budget cuts, and an extended period of reduced defense spending ahead, more of which is going to sustainment and overhead than ever before, each year prime contractors are fighting over an even smaller piece of the procurement pie, which could have a deleterious effect on national security if these contractors go out of business or further consolidate through mergers. This study used …

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A Response Surface Validation Of A Quantum Key Distribution Model, Jacob M. Ehrlich Mar 2016

A Response Surface Validation Of A Quantum Key Distribution Model, Jacob M. Ehrlich

Theses and Dissertations

The need for secure communication in the presence of an adversary introduced the field of cryptology -- the practice and study of techniques for secure communication. A common method to secure communication is to distribute a secret key among authorized parties so they can encrypt and decrypt messages between each other. By doing so, ideally, any messages intercepted by a third party are meaningless. An innovative technique to distribute a shared key is Quantum Key Distribution (QKD). QKD uses laws of quantum mechanics to generate and distribute such keys. The purpose of this thesis is to validate an existing mathematical …

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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. …

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Determination Of Fire Control Policies Via Approximate Dynamic Programming, Michael T. Davis Mar 2016

Determination Of Fire Control Policies Via Approximate Dynamic Programming, Michael T. Davis

Theses and Dissertations

Given the ubiquitous nature of both offensive and defensive missile systems, the catastrophe-causing potential they represent, and the limited resources available to countries for missile defense, optimizing the defensive response to a missile attack is a necessary endeavor. For a single salvo of offensive missiles launched at a set of targets, a missile defense system protecting those targets must decide how many interceptors to fire at each incoming missile. Since such missile engagements often involve the firing of more than one attack salvo, we develop a Markov decision process (MDP) model to examine the optimal fire control policy for the …

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Overhaul Facility Planning And Control Tool Selection And Implementation Analysis, Santiago L. Martin Mar 2016

Overhaul Facility Planning And Control Tool Selection And Implementation Analysis, Santiago L. Martin

Theses and Dissertations

The Argentine Air Force Materiel General Directorate (AAFMGD) has initiated an effort to assure logistical support and to gradually increase the productivity and efficiency of related processes. Within the efforts of increased productivity and efficiency over the AAF Overhauling Facilities, the Planning and Control Departments (PCD) became targets for improvements. These departments are tasked with providing the best certainty and visibility of all assets within their facilities to feed the logistics pipeline, and better support air operations. This thesis, sponsored by the MGD, is focused on achieving improvements in the PCD processes, through an academically rigorous evaluation of confounding factors …

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Heterogeneous Air Defense Battery Location: A Game Theoretic Approach, Nicholas T. Boardman Mar 2016

Heterogeneous Air Defense Battery Location: A Game Theoretic Approach, Nicholas T. Boardman

Theses and Dissertations

The Unites States and its allies confront a persistent and evolving threat from missile attacks as nations around the world continue to invest and advance their current capabilities. Within the air defense context of a missile-and-interceptor engagement, a challenge for the defender is that surface to air interceptor missile batteries often must be located to protect high-value targets dispersed over a vast area, subject to an attacker observing the disposition of batteries prior to developing and implementing an attack plan. To model this scenario, we formulate a two-player, three-stage, perfect information, sequential move, zero-sum game that accounts for, respectively, a …

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Epidemiology, Cost, And Aircraft Choice For Aeromedical Evacuation In Africom, Daniel A. Griffith Mar 2016

Epidemiology, Cost, And Aircraft Choice For Aeromedical Evacuation In Africom, Daniel A. Griffith

Theses and Dissertations

A significant shortfall exists in the medical capability provided to US Service members deployed to the African Area of Responsibility because of unknown epidemiology, large distances, limited resources, and high patient movement cost. The first step in closing this gap is to understand the types, demographics, diagnoses, and distribution of the patients requiring aeromedical evacuation. This research examined the DoD’s aeromedical evacuation missions from Africa between 2010 and 2014. Of the 274 patients and 170 missions identified from available data, a gap is evident in aeromedical evacuation capability with over 23% of Priority patients and almost 10% of Urgent patients …

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An Economic Analysis Of The Transition Of A Contingency Military Installation To An Enduring Status Using Monte Carlo Simulations, Ryan M. Amedee Mar 2016

An Economic Analysis Of The Transition Of A Contingency Military Installation To An Enduring Status Using Monte Carlo Simulations, Ryan M. Amedee

Theses and Dissertations

The construction of expeditionary bases is central to Department of Defense’s (DoD) responses to contingency operations. Usually expected to be transitory, expeditionary bases are constructed with temporary materials that can be erected quickly. The Global War on Terrorism is entering its fifteenth year and bases within Central Command that were expected to be temporary have provided an enduring presence. The decision to transition a base from temporary to semi-permanent or permanent is difficult, as it requires substantial capital investment for facility construction. This decision is further complicated by unknown mission durations. The DoD has attempted to reduce the decision’s complexity …

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Determining Air Base Installation Capacity Through Multivariate Analysis, Perry L. Cansick Mar 2016

Determining Air Base Installation Capacity Through Multivariate Analysis, Perry L. Cansick

Theses and Dissertations

Per the Air Force Strategic Master Plan, the Air Force will adjust their current basing structure to provide the most effective and efficient installations to support national defense objectives. The Air Force may be required to make strategic basing decisions that close installations and relocate missions to achieve an optimal basing structure. However, before making these decisions, the Air Force needs to have a comprehensive understanding of installation capacity. This research provides an operational definition of installation capacity, which is necessary for measuring installation-level, infrastructure capacity. Using this definition, the research evaluates a set of capacity indicators using principal component …

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Validation And Improvement Of Reliability Methods For Air Force Building Systems, Patrick A. Deering Mar 2016

Validation And Improvement Of Reliability Methods For Air Force Building Systems, Patrick A. Deering

Theses and Dissertations

The United States Air Force manages its civil infrastructure resource allocation via a two-dimensional risk model consisting of the consequence of failure and reliability. Air Force civil engineers currently use the BUILDER® Sustainment Management System to estimate and predict reliability at multiple levels within its civil infrastructure systems. Alley (2015) developed and validated a probabilistic model to calculate reliability at the system level. The probabilistic model was found to be a significant improvement over the currently employed BUILDER® model for four major building systems (electrical, HVAC, fire protection, and electrical). This research assessed the performance and accuracy of both the …

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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 …

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Logistics Simulation For Long Duration Logistics Wargames, Kevin R. Cardenas Mar 2016

Logistics Simulation For Long Duration Logistics Wargames, Kevin R. Cardenas

Theses and Dissertations

Wargames were originally created to test wartime strategies against opposing forces within a short time frame. Due to the short duration design of these wargames, logistics were deemed irrelevant and it was incorrectly assumed that the warfighter would be logistically supported for the entire duration of the wargame. The purpose of this thesis is to provide insight to the value of capturing logistics within a wargame and to better model the increased requirement for Agile Combat Support. This research utilizes a logistics simulation tool and its outputs to conduct statistical analyses comparing a baseline scenario created to mirror the Joint …

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Radiation Response From A Novel Uo2 Crystal, Stephan A. Varga Mar 2016

Radiation Response From A Novel Uo2 Crystal, Stephan A. Varga

Theses and Dissertations

The radiation response of a novel, single-crystalline UO2 sample was analyzed using several types of radiation. The crystal was exposed to alpha, gamma, and neutron radiation under various environmental conditions and the electronic response of the crystal was measured using a pulse shape discrimination algorithm. The distributions of pulse amplitude (Vmax) and pulse decay times (τ) were used to compare the output. This research revealed that the crystal radiation response is exceptionally sensitive to surface conditions, specifically humidity, which tends to alter the time dependent currents resulting from the radiation interactions. The pulse τ can be made to …

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Simulation Of Modeling Sortie Generation Process In Turaf, Bahadir Aykiri Mar 2016

Simulation Of Modeling Sortie Generation Process In Turaf, Bahadir Aykiri

Theses and Dissertations

Simulation is a useful technique for engineers and operations researchers. One of the primary advantages of simulation models is that they are able to provide users with practical feedback when analyzing real-world systems. This thesis builds a discrete event simulation of the sortıe generatıon process, to help decision makers in performing analyses regarding quantity of manpower, bottlenecks in supply and maintenance activities; as well as utilization of maintenance manpower, cost and number of sorties produced in a specific time. We only model one aircraft system with four Line Replacement Units (LRU), but any system and its LRUs can be included …

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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 …

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Automated Sunspot Classification And Tracking Using Sdo/Hmi Imagery, Maclane A. Townsend Mar 2016

Automated Sunspot Classification And Tracking Using Sdo/Hmi Imagery, Maclane A. Townsend

Theses and Dissertations

Verification of an automated sunspot detection and classification algorithm is conducted utilizing two years of solar imagery from NASA's Solar Dynamics Observatory (SDO) satellite. Automated McIntosh classifications are compared against sunspot reports from the National Oceanic and Atmospheric Administration’s (NOAA) Space Weather Prediction Center (SWPC) using a three-tiered comparison metric. Statistical confidence is demonstrated for algorithm performance and consistency when compared against the SWPC data set, suggesting future applications of the algorithm will perform similarly. A sunspot tracking algorithm is added to the existing code and demonstrates reliable feature tracking for time periods out to four days between consecutive images. …

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Antecedents Of Fuel Efficiency, James A. Cotton Mar 2016

Antecedents Of Fuel Efficiency, James A. Cotton

Theses and Dissertations

Reducing the United States Air Force (USAF)’s fuel use is a major budgetary concern, as the USAF consumes more fuel than the Army, Navy, Marine Corps and all other Department of Defense (DoD) agencies combined. This research focused on fuel efficiency of C-130 Hercules Aircraft Commanders (ACs) by proposing, constructing, and testing a survey measure of behavioral drivers of discretionary pro-environmental professional behaviors among USAF pilots.

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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 …

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Evaluation Of The Visible Infrared Imaging Radiometer Suite (Viirs) Cloud Base Height (Cbh) Pixel-Level Retrieval Algorithm For Single-Layer Water Clouds, Kyle E. Fitch Mar 2016

Evaluation Of The Visible Infrared Imaging Radiometer Suite (Viirs) Cloud Base Height (Cbh) Pixel-Level Retrieval Algorithm For Single-Layer Water Clouds, Kyle E. Fitch

Theses and Dissertations

Evaluation of the Visible Infrared Imaging Radiometer Suite (VIIRS) Cloud Base Height (CBH) product was accomplished. CBH is an important factor for aviation, but a lack of coverage for ground-based retrieval is a significant limitation. Space-based retrieval is essential; therefore, the VIIRS CBH pixel-level retrieval algorithm was assessed for single-layer water clouds. Accurate (truth) measurements were needed not only for the CBH product, but also for VIIRS cloud optical thickness (COT), effective particle size (EPS), and cloud top height (CTH). Data from Atmospheric Radiation Measurement (ARM) sites were used, with VIIRS-ARM matchups created from June 2013 through October 2015 for …

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Analysis Of Military Entry Control Point Queueing, Justin J. Dwyer Mar 2016

Analysis Of Military Entry Control Point Queueing, Justin J. Dwyer

Theses and Dissertations

Military Entry Control Facilities (ECFs) are unique service queues that are constrained by space, receive high peak traffic flow, and have a customer base that must receive service. Due to complexity of the interactions within the system, simulations provide input that would be impractical for quantitative experimentation. Our research examines relationships within the ECF in order to develop insights that could lead to more efficient daily operations. We focus the research on interactions that generate a queue length that would interfere with traffic flow surrounding the base. Examining the interactions between multiple arrival rates and service times as well as …

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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 …

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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 …

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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 …

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Differential (P, P′) And (P, D) Cross Sections Of 89Y And 92Zr, Molly A. Wakeling Mar 2016

Differential (P, P′) And (P, D) Cross Sections Of 89Y And 92Zr, Molly A. Wakeling

Theses and Dissertations

Differential cross sections for the (p, p′) and (p, d) reactions on 89Y and 92Zr were measured using a 28.25-MeV proton beam at the 88-inch cyclotron at Lawrence Berkeley National Laboratory. Angular distributions were obtained for the ground state and several excited states of each isotope using silicon detector telescopes over angles 10° to 140° in the reaction plane. These data were obtained by fitting a Gaussian function to each peak in the energy spectra and integrating the number of counts under each peak. These cross sections will be included in nuclear structure models …

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An Examination Of Economic Metrics As Indicators Of Air Force Retention, Helen L. Jantscher Mar 2016

An Examination Of Economic Metrics As Indicators Of Air Force Retention, Helen L. Jantscher

Theses and Dissertations

Fluctuations in the economy can cause military recruitment and retention plans to go awry. By focusing on various economic metrics, it is possible to anticipate changes in retention rates for specific Air Force Specialty Codes (AFSCs). To address the challenge of maintaining a robust and mission capable Air Force, a correlation analysis is employed to determine the relationship between certain economic indicators and AFSC retention rates. As one might suspect, retention rates follow the trend of decreasing when the economy is strong. Of interest, we found two AFSCs which go against this trend. Namely, the retention rates for officers in …

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The Impact Of Reducing Full Time Support Positions In The U.S. Army National Guard And Reserves, Lucas J. Lease Mar 2016

The Impact Of Reducing Full Time Support Positions In The U.S. Army National Guard And Reserves, Lucas J. Lease

Theses and Dissertations

The United States Army is at a point in its history in which it, along with the other branches of the military, are experiencing cuts, constraints and a tightening of resources. The days of seemingly large budgets, abundant financial resources and high amounts of manpower are becoming a thing of the past. As the government reduces the allocations to the military, it is examining ways to reduce costs and improve its financial prospects. One of the positions examined for reduction or outright elimination is the full time support position in the U.S. Army National Guard (ARNG) and Reserves (USAR). The …

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The Efficacy Of Implementing A Small, Low-Cost, Real Time Kinematic Gps System Into A Small Unmanned Aerial System Architecture, Kevin J. Hendricks Mar 2016

The Efficacy Of Implementing A Small, Low-Cost, Real Time Kinematic Gps System Into A Small Unmanned Aerial System Architecture, Kevin J. Hendricks

Theses and Dissertations

Along with the growing uses for small unmanned aerial systems (UAS) within the Department of Defense (DoD), is the utility of small UAS within the civilian market is also increasing. This has led to significant research and development on small UAS subsystems by the commercial market. The focus of this research is characterizing and investigating the application considerations of a small, low-cost real time kinematic (RTK) GPS receiver system. Work was also accomplished to characterize the accuracy and precision of the commonly used GPS receiver subsystem in small UAS to show the increased utility of the RTK GPS system. The …

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