Through application of modern technology, aviation systems are becoming more automated and are relying less on antiquated air traffic control (ATC) voice systems. Aircraft are now able to wirelessly broadcast and receive identity and location information using transponder technology. This helps reduce controller workload and allows the aircraft to take more responsibility for maintaining safe separation. However, these systems lack source authentication methods or the ability to check the integrity of message content. This opens the door for hackers to potentially create fraudulent messages or manipulate message content. This thesis presents a solution to handling many of the potential security issues in aircraft data communication. This is accomplished through the implementation of a Dual Path PKI (DPP) design which includes a novel approach to handling certificate revocation through session certificates. DPP defines two authentication protocols, one between aircraft and another between aircraft and ATC, to achieve source authentication. Digital signature technology is utilized to achieve message content and source integrity as well as enable bootstrapping DPP into current ATC systems. DPP employs cutting-edge elliptic curve cryptography (ECC) algorithms to increase performance and reduce overhead. T is found that the DPP design successfully mitigates several of the cyber security concerns in aircraft and ATC data communications. An implementation of the design shows that anticipated ATC systems can accommodate the additional processing power and bandwidth required by DPP to successfully achieve system integrity and security. / Master of Science

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In this work, a user-friendly MATLAB tool is introduced to solve nonlinear optimal control problems by applying collocation techniques using Coupled Radial Basis Functions (CRBFs). CRBFs are a new class of Radial Basis Functions combined with a conical spline r^5, which provides the advantage of insensitivity to the shape parameter while maintaining accuracy and robustness. To solve optimal control problems, software tools are often employed to implement numerical methods and apply advanced techniques to solving differential equations. Although several commercial software tools exist for solving optimal control problems, such as ICLOCS2, GPOPS, and DIDO, there are no options available that utilize adaptive collocation with CRBFs. A unified MATLAB tool named Radial Optimal Control Software (ROCS) is introduced and not only implements the CRBF method, but also enables any user, from professionals to students, to solve nonlinear optimal control problems through a user-friendly interface. The tool accepts user input for boundary conditions, necessary conditions, and the governing equations of motion. The two-point boundary value problem (TPBVP) is approximated through collocation using CRBFs, and the resulting nonlinear algebraic equations (NAEs) are solved with a MATLAB solver. The tool's usefulness and application are demonstrated by solving classical nonlinear optimal control problems and comparing the results with the solutions found in the literature. Compared to classical numerical method techniques, the present tool is shown to solve optimal control problems more efficiently for the same level of accuracy. By introducing this unified MATLAB tool to solving nonlinear optimal control problems, the intent is to enable professionals and students to solve nonlinear optimal control problems, e.g., in astrodynamics and space-flight mechanics, without the need for extensive manipulation of code in existing software tools and without extensive knowledge of applying numerical solvers.

Traffic signal control is an effective way to improve the efficiency of traffic networks and reduce users’ delays. Ant Colony Optimization (ACO) is a metaheuristic based on the behavior of ant colonies searching for food. ACO has successfully been used to solve many NP-hard combinatorial optimization problems and its stochastic and decentralized nature fits well with traffic flow networks. This thesis investigates the application of ACO to minimize user delay at traffic intersections. Computer simulation results show that this new approach outperforms conventional fully actuated control under the condition of high traffic demand.

This thesis deals with the development of an Airspace Sector Occupancy Model (ASOM). The model determines the occupancy of Air Traffic Control Center (ARTCC) sectors for a given geometry of sectors and flight schedules, and can be used to study the impact of alternative flight schedules on the workload imposed on the sectors. Along with complimentary airspace analysis models, this can serve as an advisory tool to approve flight plans in the Free Flight Scenario, or to reschedule flights around a Special Use Airspace (SUA). ASOM is developed using Matlab 5.2, and can be run on an IBM compatible PC, Macintosh, or Unix Workstation. The computerized model incorporates the powerful features of graphics and hierarchical modeling inherent in Matlab, to design an effective tool for analyzing air traffic scenarios and their respective sector occupancies. / Master of Science

The scope of this study was to evaluate the impact of the air traffic controller-to-pilot communication standard known as CPDLC or Data-Communication on the future air traffic operations. The impact was evaluated from the double viewpoint of airport delays and air traffic controllers' workload. RAMS simulation software is used to perform all the runs and from its output data the values of terminal area delays and controllers workload are obtained. The New York Metroplex terminal area was used as a case study. Because of its complexity, where three major airports (i.e. JFK, Newark, and La Guardia) interact and constraint each other, this area was particularly interesting to be studied and the data analyzed gave a valuable insight on the possible future impact of Data-Communication in congested terminal areas. The results of the study, based on some previous man-in-the-loop simulations performed by the FAA in the nineties, showed that significant potential benefits could be obtained with the complete implementation of such technologies in the workload experienced by air traffic controllers. Moreover some small but not negligible benefits were obtained in the total delays accrued by each airport studied. On the other hand, the simulations of the future demand predicted by the FAA demonstrated that without a significant increment in capacity or limitation on the traffic growth intolerable delays would be recorded across the NAS in the future. For the complexity of the simulation model calibration and for the very time-consuming run time not all the scenarios described in the methodology were tested, demonstrating the weakness of RAMS as a ground simulation model. / Master of Science

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The National Aeronautics and Space Administration (NASA) is leading a research effort to develop a Small Aircraft Transportation System (SATS) that will expand air transportation capabilities to hundreds of underutilized airports in the United States. Most of the research effort addresses the technological development of the small aircraft as well as the systems to manage airspace usage and surface activities at airports. The Federal Aviation Administration (FAA) will also play a major role in the successful implementation of SATS, however, the administration is reluctant to embrace the unproven concept. The purpose of the research presented in this dissertation is to determine if the FAA can pursue a resource management strategy that will support the current radar-based Air Traffic Control (ATC) system as well as a Global Positioning Satellite (GPS)-based ATC system required by the SATS. The research centered around the use of the System Dynamics modeling methodology to determine the future behavior of the principle components of the ATC system over time. The research included a model of the ATC system consisting of people, facilities, equipment, airports, aircraft, the FAA budget, and the Airport and Airways Trust Fund. The model generated system performance behavior used to evaluate three scenarios. The first scenario depicted the base case behavior of the system if the FAA continued its current resource management practices. The second scenario depicted the behavior of the system if the FAA emphasized development of GPS-based ATC systems. The third scenario depicted a combined resource management strategy that supplemented radar systems with GPS systems. The findings of the research were that the FAA must pursue a resource management strategy that primarily funds a radar-based ATC system and directs lesser funding toward a GPS-based supplemental ATC system. The most significant contribution of this research was the insight and understanding gained of how several resource management strategies and the presence of SATS aircraft may impact the future US Air Traffic Control system. / Ph. D.

Currently, there is a significant increase in oceanic air traffic. The Federal Aviation Administration (FAA) is attempting to keep pace with this traffic. Automation is being planned in the airline and Air Traffic Control (ATC) system; eventually, all oceanic functions will be part of the FAA Advanced Automation System (AAS). The Oceanic Display and Planning System (ODAPS) capabilities include oceanic flight data processing, conflict probe, flight strip printing; and aircraft situation display capabilities. The Fight Data Input/Output (FDIO) device is currently being used as the main controller input device to the ODAPS. The objective of the Oceanic Air Traffic Control System (OATCS) is to replace the FDIO device with a system that will provide more flexibility and assistance to the oceanic air traffic controller in interfacing with the ODAPS The OA TCS being proposed by this research and thesis is an interim system in support of planned automation. The OATCS will provide the controller with the ability to scroll, and search through previous received ODAPS update, alert, and response messages, and to compose and edit ODAPS flight plan messages. The OATCs will augment and enhance the current functionality of the FDIO system of the ODAPS by providing high technology workstations similar to AAS. The OATCS also will provide the capability to process Automatic Depending Surveillance (ADS) position reports by replacing ODAPS peripherals to improve the working environment for oceanic controllers, the ARINC Communication Center, and the pilot. In addition, the OATCS will support a future two way data link between the oceanic controller and the pilot. / Master of Science

One of the major problems plaguing the airline industry in recent years has been the steady increase in the number and duration of flight delays. Airports have not been able to keep pace with the increase in air traffic. Consequently, Congress has directed the Federal Aviation Administration (FAA) to initiate programs to reduce delays and improve airport capacity. One program the FAA has initiated evaluates the simultaneous use of three and four closely spaced parallel runways. These operations would allow cost efficient capacity increases through concurrent use of already constructed runways and through the construction of additional runways at existing airports. Recent simulation studies have indicated that improvements in controller displays are required to safely conduct multiple parallel ILS approaches to runways spaced 4300 ft apart or less. This study was designed to quantify the ability of the Precision Runway Monitor (PRM) display to enhance controller performance over the current display, the Automated Radar Terminal System (ARTS) ILIA. Additionally, the effects of blunder degree and the number of simultaneous parallel approach operations (dual or triple approaches) on the controller's ability to detect aircraft blunders were also examined. A blunder is an unusually sharp turn by an aircraft off its ILS localizer course toward an adjacent ILS course. The PRM display, a high resolution raster scan color monitor, enhanced the controller's ability to quickly detect aircraft blunders over the ARTS ILIA display (the current display system), a Plan position Indicator (PPI). The average controller response times were smaller (4 seconds) and the average closest points of approach (CPAs) between the blundering and the evading aircraft were larger (776 ft) when the controllers used the PRM display. As in earlier studies, the thirty degree blunders resulted in conflicts that were more severe than the conflicts associated with twenty degree blunders. Conversely, contrary to earlier studies, the controllers were able to detect the twenty degree blunders as quickly as they detected thirty degree blunders. The controllers performed as well in the dual parallel approach operation as they did in the triple approach operation for all measures. The results of this study generally agreed with those found in earlier studies on controller performance. Controller performance can be improved with the use of high resolution displays with alert systems. However, unlike earlier studies, this study provided a quantification of the benefit of a proposed system relative to the current system. / Master of Science