Digital Commons Network^™

Gnss Software Defined Radio: History, Current Developments, And Standardization Efforts, Thomas Pany, Dennis Akos, Javier Arribas, M. Zahidul H. Bhuiyan, Pau Closas, Fabio Dovis, Ignacio Fernandez-Hernandez, Carles Fernandez-Prades, Sanjeev Gunawardena, Todd Humphreys, Zaher M. Kassas, Jose A. Lopez Salcedo, Mario Nicola, Mario L. Psiaki, Alexander Rugamer, Yong-Jin Song, Jong-Hoon Won

Faculty Publications

Taking the work conducted by the global navigation satellite system (GNSS) software-defined radio (SDR) working group during the last decade as a seed, this contribution summarizes, for the first time, the history of GNSS SDR development. This report highlights selected SDR implementations and achievements that are available to the public or that influenced the general development of SDR. Aspects related to the standardization process of intermediate-frequency sample data and metadata are discussed, and an update of the Institute of Navigation SDR Standard is proposed. This work focuses on GNSS SDR implementations in general-purpose processors and leaves aside developments conducted on …

The Afit Engineer, Volume 4, Issue 4, Graduate School Of Engineering And Management, Air Force Institute Of Technology

AFIT Documents

In this issue:

• Data Analytics and Data Science Programs
• Faculty Retirements
• CSRA 10^th Anniversary
• Distance Learning
• New Hypersonic Flight Certificate Program

Contested Agile Combat Employment: A Site-Selection Methodology, Zachary T. Moer, Christopher M. Chini, Peter P. Feng, Steven J. Schuldt

Faculty Publications

Numerous factors complicate ACE site-selection decisions including peer-to-peer threats, complex geopolitics, and resource requirements. The proposed site-selection framework identifies existing airports best suited for strategic utilization to support combatant commands as they optimize agile combat employment infrastructure.

Using Blockchain To Track Dod Funding And Auditing, Prithvi Prasanna

Theses and Dissertations

The Department of Defense (DoD) currently faces a significant problem when it comes to auditing and tracking financial transactions. The DoD has failed every audit since 2017 although it is gradually improving its auditable rating year after year. Concurrently, Blockchain is an emerging technology that has typically been used for cryptocurrencies but has slowly been adapted by private enterprises for their auditing and invoicing problems. This study investigates the value proposition of blockchain technology to improve DoD financial tracking and auditing. To test the hypothesis that blockchain is the optimal option for the DoD, this paper employs an industry blockchain …

Pilot Development: An Empirical Mixed-Method Analysis, Jonathan Slottje, Jason Anderson, John M. Dickens, Adam D. Reiman

Faculty Publications

Purpose — Pilot upgrade training is critical to aircraft and passenger safety. This study aims to identify variances in the US Air Force C-130J pilot upgrade training based on geographic location and provide a model to enhance policy that will impact future pilot training efforts that lower cost and increase operator quality and proficiency.
Design/methodology/approach — This research employed a mixed-method approach. First, the authors collected data and analyzed 90 C-130J pilots' aviation records and then contextualized this analysis with interviews of experts. Finally, the authors present a modified version of Six Sigma's define–measure–analyze–improve–control (DMAIC) that identifies and reduces the …

Applying Models Of Circadian Stimulus To Explore Ideal Lighting Configurations, Alexander J. Price

Theses and Dissertations

Increased levels of time are spent indoors, decreasing human interaction with nature and degrading photoentrainment, the synchronization of circadian rhythms with daylight variation. Military imagery analysts, among other professionals, are required to work in low light level environments to limit power consumption or increase contrast on display screens to improve detail detection. Insufficient exposure to light in these environments results in inadequate photoentrainment which is associated with degraded alertness and negative health effects. Recent research has shown that both the illuminance (i.e., perceived intensity) and wavelength of light affect photoentrainment. Simultaneously, modern lighting technologies have improved our ability to construct …

A United States Air Force Site Selection Methodology In A Contested Agile Combat Employment Environment, Zachary T. Moer

Theses and Dissertations

The United States Air Force’s (USAF) Agile Combat Employment (ACE) strategy relies on host country access and underlying local infrastructure to facilitate airpower. However, numerous factors, including peer-to-peer threats, complex geopolitics, and intricate supply chain management, often complicate site access and thwart site selection decisions. When shaping the battlespace for future conflict, strategists and planners face the difficult task of identifying optimal locations to conduct adaptive basing operations given these complicating factors. Multi-Criteria Decision Analysis (MCDA) can help strategists appropriately account for competing objectives and maintain a competitive advantage with theater adversaries. This thesis presents an MCDA model that evaluates …

Hydrologic Profiles And Geospatial Trend Analysis Evaluating Recurrent Flooding At Coastal U.S. Air Force Installations, Dylan D. Bechen

Theses and Dissertations

Military installations are exposed to numerous threats, including a changing climate and the risk of recurrent flooding. The four components of recurrent flooding are sea-level rise, tidal fluctuations, storm surges, and precipitation. This research analyzed 40 years of historical precipitation and tidal data at 17 coastal U.S. Air Force installations using indicators of both peak and threshold exceedances to identify long-term temporal trends in the hydrologic components that make up recurrent flood risk, establishing an installation’s “hydrologic profile” which can be used to better inform decision makers when evaluating portfolio-wide adaptation strategies and prioritization of long-term infrastructure investments.

A Framework For Assessing Facility-Level Vulnerability And Risk To Extreme Weather Events, Blake A. Gawlik

Theses and Dissertations

Intensifying extreme weather events, tied to the rise in the global average temperature, put global built infrastructure at risk. This presents a daunting challenge for organizational leaders who are tasked to determine how best to adapt current infrastructure to uncertain future events. To develop adaptation plans and policies, vulnerability and risk must be downscaled to an actionable scale, such that planners, designers, and engineers can make adaptation recommendations. However, previous research has largely assessed risk at coarser scales, e.g., regional, national, or global. These assessments are informative, but do not help those tasked to lead adaptation to make detailed, actionable …

Analysis Of Twitter Networks To Aid Open Source Intelligence Capabilities: A Multilayer Network Approach, Austin P. Logan

Theses and Dissertations

Open Source Intelligence using social media is a practice which gives military intelligence analysts a window into the thoughts and minds of an online population. Using Social Network Analysis, user interactions on Twitter will be modeled as a weighted and directed network. Topic modeling through Latent Dirichlet Allocation uncovers the topics of discussion in Tweets and is then integrated into a multi-layer network which allows users to be connected to the conversations with which they have participated. Influential users in this network as well as highly connected groups of individuals are then discovered to paint a picture for intelligence analysts …

Magnetic Navigation Using Online Calibration Filter Analysis, Jonnathan D. Bonifaz

Theses and Dissertations

Magnetic navigation using the Earth’s magnetic anomaly field has proven to be a promising alternative that can provide coverage for a navigation system. This research demonstrates a magnetic navigation system using an extended Kalman filter (EKF) to aid an aircraft’s inertial navigation system (INS). Traditional magnetic anomaly navigation uses a “static calibration method,” which takes post-processed data to calibrate, obtaining the Tolles-Lawson coefficients needed for magnetic anomaly navigation filter compensation. These coefficients are constant and may cause drifts in the navigation filter if not re-calibrated. The online calibration method continuously updates the Tolles-Lawson coefficients as a filter state, reducing the …

Burn Probability And Climate Change: A Quantitative Evaluation Of The Temporal Alterations Of Wildfire, David N. Robinson

Theses and Dissertations

The intensity of extreme weather events, specifically wildfires, along the West Coast has slowly grown overtime due to atmospheric changes caused by climate change. The Air Force, though aware of the threat that is wildfire, does not currently have a quantitative way to assess the hazard to base locations. In this paper, burn probability is quantitatively calculated through the geospatial analysis programs to provide a means of assessing wildfire vulnerability. The FlamMap fire simulator generated burn probabilities for Vandenberg Air Force Base using climate data generated by the remote automated weather station on the base to highlight how the burn …

Academic Year 2021-2022 Faculty Excellence Showcase, Afit Graduate School Of Engineering & Management, Graduate School Of Engineering And Management, Air Force Institute Of Technology

AFIT Documents

No abstract provided.

Developing A Resilient, Robust And Efficient Supply Network In Africa, Jade F. Preston, Bruce A. Cox, Paul P. Rebeiz, Timothy W. Breitbach

Faculty Publications

Purpose — Supply chains need to balance competing objectives; in addition to efficiency, supply chains need to be resilient to adversarial and environmental interference and robust to uncertainties in long-term demand. Significant research has been conducted designing efficient supply chains and recent research has focused on resilient supply chain design. However, the integration of resilient and robust supply chain design is less well studied. The purpose of the paper is to include resilience and robustness into supply chain design. Design/methodology/approach — The paper develops a method to include resilience and robustness into supply chain design. Using the region of West …

Academic Year 2020-2021 Faculty Excellence Showcase, Afit Graduate School Of Engineering & Management, Graduate School Of Engineering And Management, Air Force Institute Of Technology

AFIT Documents

No abstract provided.

Design And Performance Characterization Of A Water Propellant Resistojet Thruster, Sean M. Weathersby

Theses and Dissertations

Secondary payloads, such as CubeSats, are being increasingly used by the US Department of Defense in the role of defense capability enhancement, and these increasingly complex defense missions can require extended lifespans that result in the need for a thruster. While many thruster options exist, characteristics such as propellant toxicity, complexity, and low performance limit many viable solutions. However, a potential answer that satisfies these thruster limitations is found in electrothermals, specifically the resistojet. The research presented here represents the first attempt to construct a 1U water-propellant resistojet thruster design and establish an initial characterization through evaluation of various performance …

Enterprise Resource Allocation For Intruder Detection And Interception, Adam B. Haywood

Theses and Dissertations

This research considers the problem of an intruder attempting to traverse a defender's territory in which the defender locates and employs disparate sets of resources to lower the probability of a successful intrusion. The research is conducted in the form of three related research components. The first component examines the problem in which the defender subdivides their territory into spatial stages and knows the plan of intrusion. Alternative resource-probability modeling techniques as well as variable bounding techniques are examined to improve the convergence of global solvers for this nonlinear, nonconvex optimization problem. The second component studies a similar problem but …

Interdependent Infrastructure Recovery Using Multilayered Networks And Optimization, Brigham A. Moore

Theses and Dissertations

Interdependent infrastructure recovery modeling and simulation are complicated due to various interdependent connections and complexities. Current efforts have identified both operational and restoration interdependency subtypes and coupling strategies that have not been integrated into one comprehensive model. This research presents a model which simultaneously integrates nine interdependency subtypes and four coupling strategies in a multi-objective format to provide the most tailorable and comprehensive network-based recovery model available. This research also created a defense-centric interdependent infrastructure database by modifying the existing CLARC database. This research then addressed assumptions regarding recovery work management in order to address the impact of work crew …

The Afit Engineer, Volume 3, Issue 2, Graduate School Of Engineering And Management, Air Force Institute Of Technology

AFIT Documents

In this issue:

• Women in STEM2021
• AETC Challenge Award winners at AFIT
• Commencement highlights
• ...and more.

Per-Pixel Cloud Cover Classification Of Multispectral Landsat-8 Data, Salome E. Carrasco [*], Torrey J. Wagner, Brent T. Langhals

Faculty Publications

Random forest and neural network algorithms are applied to identify cloud cover using 10 of the wavelength bands available in Landsat 8 imagery. The methods classify each pixel into 4 different classes: clear, cloud shadow, light cloud, or cloud. The first method is based on a fully connected neural network with ten input neurons, two hidden layers of 8 and 10 neurons respectively, and a single-neuron output for each class. This type of model is considered with and without L2 regularization applied to the kernel weighting. The final model type is a random forest classifier created from an ensemble of …

Air Force Institute Of Technology Research Report 2020, Graduate School Of Engineering And Management, Air Force Institute Of Technology

AFIT Documents

This Research Report presents the FY20 research statistics and contributions of the Graduate School of Engineering and Management (EN) at AFIT. AFIT research interests and faculty expertise cover a broad spectrum of technical areas related to USAF needs, as reflected by the range of topics addressed in the faculty and student publications listed in this report. In most cases, the research work reported herein is directly sponsored by one or more USAF or DOD agencies. AFIT welcomes the opportunity to conduct research on additional topics of interest to the USAF, DOD, and other federal organizations when adequate manpower and financial …

Data- Driven Asset Degradation Modeling: An Enterprise-Wide Roof System Case Study, Kurt R. Lamm

Theses and Dissertations

Organizations with large facility and infrastructure portfolios have used asset management databases for over ten years to collect and standardize asset condition data. Decision makers use this data to predict asset degradation and expected service life, enabling prioritized maintenance, repair, and renovation actions that reduce asset life-cycle costs and achieve organizational objectives. However, these asset condition forecasts are calculated using standardized, self-correcting distribution models that rely on continuous functions. This research presents four step wise asset condition forecast models that utilize historical asset inspection data to improve prediction accuracy: (1) Slope, (2) Weighted Slope, (3) Condition-intelligent Weighted Slope, and (4) …

Developing Infrastructure Adaptation Pathways To Combat Hurricane Intensification: A Coupled Storm Simulation And Economic Modeling Framework For Coastal Installations, Alexander J. Baldwin

Theses and Dissertations

Climate change projections suggest intensification of extreme weather events, including hurricanes, is expected throughout the 21st century. This will lead to increased destruction for coastal military bases unless infrastructure resiliency and adaptation measures are implemented. This research focuses on examining the simulation of probabilistic, climate-intensified hurricane events at Eglin Air Force Base. FEMA Hazus models are combined with climate projections for wind Intensity, tide, and sea-level rise to produce an assessment of losses to the installation. Damage estimates and hurricane intensity outputs are downscaled to the facility-level so that climate adaptation signals can be identified. The facility losses and climate …

Water Security At United States Air Force Installations, John D. Pollock

Theses and Dissertations

Global water security is a growing concern that poses unique challenges that stem from geopolitical arrangement, regional location, and local climate conditions. United States national defense relies on an uninterrupted water supply to sustain operations to carry out its readiness mission. Accurate water security assessments are necessary for adapting to climate factors and to provide essential information to meet the changing needs of human water demand. This research presents how different water metrics are applied at various United States Air Force locations to measure water scarcity. Geographical Information Systems (GIS) software is used to conduct spatial correlation across the United …

Exploring Fog Of War Concepts In Wargame Scenarios, Dillon N. Tryhorn

Theses and Dissertations

This thesis explores fog of war concepts through three submitted journal articles. The Department of Defense and U.S. Air Force are attempting to analyze war scenarios to aid the decision-making process; fog modeling improves realism in these wargame scenarios. The first article "Navigating an Enemy Contested Area with a Parallel Search Algorithm" [1] investigates a parallel algorithm's speedup, compared to the sequential implementation, with varying map configurations in a tile-based wargame. The parallel speedup tends to exceed 50 but in certain situations. The sequential algorithm outperforms it depending on the configuration of enemy location and amount on the map. The …

Real-Time Aerial Magnetic And Vision-Aided Navigation, Daniel J. Clarke

Theses and Dissertations

Aerial magnetic navigation has shown to be a viable alternative navigation method that has the potential for world-wide availability, to include over oceans. Obtaining GPS-level accuracy using magnetic navigation alone is challenging, but magnetic navigation can be combined with other alternative navigation methods that are more posed to obtaining GPS-level accuracy in their current state. This research presents an aerial navigation solution combining magnetic navigation and vision-aided navigation to aid an inertial navigation system (INS). The navigation solution was demonstrated in real-time playback using simulated magnetic field measurements and flight-test captured visual imagery. Additionally, the navigation solution was flight-tested on …

Conversion From Coal To Natural Gas At Wright Patterson Air Force Base: An Analysis And Case Study, Tyler A. Ferry

Theses and Dissertations

Over the last 20 years, natural gas has replaced coal as the preferred fossil fuel for heat and power generation across the United States, due to its increased prevalence, lower cost, and reduced environmental impacts. While most conversion decisions are driven by cost savings, proponents of energy transitions often cite emissions reductions as a tangential benefit. Over the same time, climate change and its impact on the environment and society have come to the forefront of scientific inquiry. One example of the transition from coal to natural gas can be found in Dayton, Ohio. Wright Patterson Air Force Base (WPAFB) …

Continuous Integration/Continuous Delivery Pipeline For Air Force Distributed Common Ground System (Af Dcgs), Carolyn W. Fuller

Theses and Dissertations

AF DCGS has a recognized need to improve speed of delivery for modification and sustainment of the weapon system. Given that the program office implemented a Continuous Integration/Continuous Delivery (CI/CD) process for the sole purpose of delivering capability to the field faster, there is a need to measure and report the pipeline throughput. This research conducts an independent evaluation of the newly implemented pipeline within AF DCGS’s existing integration and test laboratories. Actual project data from the agile development work environments is studied and hypothesis tests are conducted to substantiate that the CI/CD pipeline improved the speed of delivery. The …

Graduate School Of Engineering And Management Fall 2020 Fact Book, Graduate School Of Engineering And Management, Air Force Institute Of Technology

AFIT Documents

No abstract provided.

Cyberspace Odyssey: A Competitive Team-Oriented Serious Game In Computer Networking, Kendra Graham [I], James Anderson [I], Conrad Rife [I], Bryce Heitmeyer [I], Pranav R. Patel [*], Scott L. Nykl, Alan C. Lin, Laurence D. Merkle

Faculty Publications

Cyber Space Odyssey (CSO) is a novel serious game supporting computer networking education by engaging students in a race to successfully perform various cybersecurity tasks in order to collect clues and solve a puzzle in virtual near-Earth 3D space. Each team interacts with the game server through a dedicated client presenting a multimodal interface, using a game controller for navigation and various desktop computer networking tools of the trade for cybersecurity tasks on the game's physical network. Specifically, teams connect to wireless access points, use packet monitors to intercept network traffic, decrypt and reverse engineer that traffic, craft well-formed and …