Die Flugsicherung in Europa befindet sich im Wandel, denn der Europäische Luftraum und die damit verbundenen Prozesse werden seit einigen Jahren harmonisiert. Eine Vielzahl der Forschungsprojekte, die diese Entwicklung begleiten, zielt darauf ab, eine orts- und außensichtunabhängige Arbeitsumgebung für Fluglotsen zu entwickeln. Insbesondere für kleinere Regionalflughäfen besteht die Idee, eine Fernüberwachung in einem Control Center zu bündeln, da die Fluglotsen bis auf die üblichen Peak-Zeiten häufig nicht ausgelastet und teilweise unterfordert sind. Dies ermöglicht nicht nur die Fernüberwachung eines Flughafens, sondern auch die gleichzeitige Überwachung und Kontrolle aller Flugbewegungen von mehreren Flughäfen. Neben den bisherigen Aufgaben eines Fluglotsen, wie das Überwachen des Verantwortungsbereichs und die Gewährleistung einer sicheren und zügigen Abwicklung des Flugplatzverkehrs, ist bei einer Mehrfachkontrolle (Multi-Airport-Control) die Planung des Verkehrsflusses auf den zu kontrollierenden Flughäfen von entscheidender Bedeutung. Neben Systemen zum Außensichtersatz ist hierbei daher auch ein System erforderlich, dass dem Fluglotsen bei der Planung der Flugbewegungen aller Flughäfen unterstützt. Unter Berücksichtigung eines nutzerzentrierten Ansatzes, Richtlinien für einfach bedienbare Benutzerschnittstellen und mit der Intention, auch im Arbeitskontext eine hohe User Experience (UX) zu bieten, wurde das Assistenzsystem MasterMAN entwickelt. Das Konstrukt der User Experience verfolgt einen ganzheitlichen Ansatz und beinhaltet nicht nur sachbezogene Aspekte wie die Usability des Systems sondern auch hedonische Aspekte wie Nutzeremotionen. Folglich wurde eine interaktive grafische Benutzeroberfläche gestaltet, die sowohl einen leichten und sicheren Umgang mit dem System als auch ein anspruchsvolles, positiv empfundenes Look and Feel gewährleistet. Bei der Evaluierung des Systems wurden neben der analytischen Inspektionsmethode Heuristische Evaluation nach Nielsen (1994) auch die ästhetischen Aspekte der grafischen Benutzerschnittstelle mit dem Fragebogen VisAWI (Visual Aesthetics of Websites Inventory) nach Thielsch & Moshagen (2014) adressiert. Acht Usability-Experten bewerteten das Assistenzsystem, notierten alle Auffälligkeiten und Usability-Probleme und führten ein dazugehöriges Severity Rating durch. Unter Zuhilfenahme dieser Vorgehensweise wurden insgesamt 56 Probleme identifiziert, die im weiteren Verlauf der Entwicklung korrigiert wurden. In einer abschließenden Gruppendiskussion mit allen Evaluatoren und den Entwicklern wurden nach dem Vorbild des Pluralistic Walkthrough die Probleme besprochen und Lösungsansätze mit den Usability-Experten erarbeitet. Hinsichtlich der ästhetischen Gestaltung der Benutzerschnittstelle ergab die VisAWIBewertung ein überdurchschnittliches Ergebnis und bestätigte damit ein ansprechendes Design. Weitere Untersuchungen zur Zufriedenheit von Fluglotsen beim Umgang mit dem System sind geplant.

This research is concerned with the modeling and development of algorithmic approaches for solving airport operational problems that arise in Air Traffic Control (ATC) systems within the terminal area at hub airports. Specifically, the problems addressed include the Aircraft Sequencing Problem (ASP) for runway operations, the Network Assignment Problem (NAP) for taxiway operations, and a simulation model for the evaluation of current or proposed ATC system in detail. For the ASP, we develop a mathematical model and apply the Reformulation-Linearization-Technique (RLT) of Sherali and Adams to construct an enhanced tightened version of the proposed model. Since ASP is NP-Hard and in fact, it is a variation of the well-known Traveling Salesman Problem with time-windows, sub-optimal solutions are usually derived to accommodate the real-time constraints of ATC systems. Nevertheless, we exhibit a significant advancement in this challenging class of problem. Also for the purpose of solving relatively large sized problems in practice, we develop and test suitable heuristic procedures. For the NAP, we propose a quasi-dynamic assignment scheme which is based on the incremental assignment technique. This quasi-dynamic assignment method assumes that the current aircraft route is influenced only by the previous aircraft assigned to the network. This simplified assumption obviates the need for iterative rerouting procedures to reach a pure equilibrium state which might not be achievable in practical taxiway operations. To evaluate the overall system, we develop a microscopic simulation model. The simulation model is designed to have the capability for reproducing not only the dynamic behavior of aircraft, but also incorporates communication activities between controllers and pilots. These activities are critical in ATC operations, and in some instances, might limit the capacity of the facility. Finally, using the developed simulation model named Virginia Tech Airport Simulation Model (VTASM) in concert with ASP and NAP, we compare the overall efficiencies of several control strategies, including that of the existing control system as well as of the proposed advanced control system. / Ph. D.

No description available.

A research report submitted to the Faculty of Humanities, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Arts (Organisational Psychology), 2017 / The aim of the present study was to utilise a mixed methods design as a means of investigating the relation between job demands, job resources, safety, and burnout in Air Traffic Management (ATM) technicians. It was also of interest to determine participants’ perspectives on the job demands and resources that may be present in their occupational environment, their participation in safety behaviours, and their perceptions regarding their work and safety performance. Non-probability, convenience sampling was employed to acquire the participants of the present research study. Participants included 33 ATM technicians (50.77% response rate) who took part in the quantitative component of the research study and 14 ATM who took part in the interview process. Participants’ ages ranged from 27 to 55 years (M = 38.91; SD = 8.76) and 90.1% were male (n = 30). Jackson and Rothmann’s (2005) original Job Demands-Resources Scale was used for the assessment of the job demands and resources sixteen items were also added to the original JDRS scale. Sixteen items were added to incorporate the possible job resources and demands experienced by ATM technicians, which were separated into the following sub-scales: shifts, weather conditions, travel, and equipment. Schaufeli, Leiter, Maslach, and Jackson’s (1996) Maslach Burnout Inventory-General Survey (MBIGS) was used to assess ATM technicians’ burnout. Safety behaviours were assessed through the integration of items found within two safety behaviour scales developed by Neal and Griffin (2006) and Hofmann and Morgeson (1999). A semi-structured interview process consisting of open-ended questions was used to discuss the following issues: job tasks, job demands, job resources, burnout, job safety, work-family spillover, and job performance. The findings depicted a weak, positive correlation between the perception of job demands and the experience of burnout (r = .376, p < .05) and a weak, negative correlation between the perception of job resources and the experience of burnout (r = -.383, p < .05). Job resources significantly predicted the experience of burnout (β = -.494, p = .002), as did job demands (β = .489, p = .003). A moderate, positive correlation between the perception of job resources and safety behaviours was obtained (r = .514, p < .01). The participants’ perceptions of job resources explained 26.5% of the variance in safety behaviours, (R2= .265, F(1, 31) = 11.16, p < 0.05. ATM technicians took part in the following safety behaviours: they consistently communicated with both management and air traffic controllers as a way of knowing exactly what the problem is before they went to a site, they took part in training programs as a means of keeping up to date with the latest technological knowledge, attended safety meetings, always communicated with management on how to increase safety, and made sure that a first aid kit was always available. ATM technician’s safety and performance appeared to be heavily influenced by their own personal understanding of the occupation’s risks, the weather conditions that take place on each specific site, the safety equipment that is worn, the knowledge of the possible repercussions that may arise from making any mistakes, and their own individual mood or disposition. / XL2018

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No description available.

In recent years, unmanned aerial vehicles (UAVs) have become a dominant force in the aerospace industry. Recent technological developments have moved these aircraft from remote operation roles to more active response missions. Of particular interest is the possibility of applying UAVs toward solving complex problems in long-endurance missions. Under that belief, the feasibility of utilizing UAVs for wildfire detection and response was investigated in a partnership that included NASA’s Aeronautics Research Mission Directorate and Science Mission Directorate, and the United States Forest Service. Under NASA’s Intelligent Mission Management (IMM) project, research was conducted to develop a mission architecture that would enable use of a high altitude UAV to search for reported wildfires with a separate low altitude UAV supporting ground assets. This research proposes a “straw man” concept incorporating both a High Altitude Long Endurance (HALE) UAV and a Low Altitude Short Endurance (LASE) UAV in a loosely coupled, low cost solution tailored towards wildfire response. This report identifies the communications architecture, algorithms, and required system configuration that meets the outlined goals of the IMM project by mitigating wildfires and addressing the United States Forest Service immediate needs. The end product is a defined parent-child framework capable of meeting all wildfire mission goals. The concept has been implemented in simulation, the results of which are presented in this report.

No description available.

We develop and evaluate two significant modeling concepts within the context of a large-scale Airspace Planning and Collaborative Decision-Making Model (APCDM) and, thereby, enhance its current functionality in support of both strategic and tactical level flight assessments. The first major concept is a new severe weather-modeling paradigm that can be used to assess existing tactical en route flight plan strategies such as the Flight Management System (FMS) as well as to provide rerouting strategies. The second major concept concerns modeling the mediated bartering of slot exchanges involving airline trade offers for arrival/departure slots at an arrival airport that is affected by the Ground Delay Program (GDP), while simultaneously considering issues related to sector workloads, airspace conflicts, as well as overall equity concerns among the airlines. This research effort is part of an $11.5B, 10-year, Federal Aviation Administration (FAA)-sponsored program to increase the U.S. National Airspace (NAS) capacity by 30 percent by the year 2010. Our innovative contributions of this research with respect to the severe weather rerouting include (a) the concept of "Probability-Nets" and the development of discretized representations of various weather phenomena that affect aviation operations; (b) the integration of readily accessible severe weather probabilities from existing weather forecast data provided by the National Weather Service (NWS); (c) the generation of flight plans that circumvent severe weather phenomena with specified probability levels, and (d) a probabilistic delay assessment methodology for evaluating planned flight routes that might encounter potentially disruptive weather along its trajectory. Given a fixed set of reporting stations from the CONUS Model Output Statistics (MOS), we begin by constructing weather-specific probability-nets that are dynamic with respect to time and space. Essential to the construction of the probability-nets are the point-by-point forecast probabilities associated with MOS reporting sites throughout the United States. Connections between the MOS reporting sites form the strands within the probability-nets, and are constructed based upon a user-defined adjacency threshold, which is defined as the maximum allowable great circle distance between any such pair of sites. When a flight plan traverses through a probability-net, we extract probability data corresponding to the points where the flight plan and the probability-net strand(s) intersect. The ability to quickly extract this trajectory-related probability data is critical to our weather-based rerouting concepts and the derived expected delay and related cost computations in support of the decision-making process. Next, we consider the superimposition of a flight-trajectory-grid network upon the probability-nets. Using the U.S. Navigational Aids (Navaids) as the network nodes, we develop an approach to generate flight plans that can circumvent severe weather phenomena with specified probability levels based on determining restricted, time-dependent shortest paths between the origin and destination airports. By generating alternative flight plans pertaining to specified threshold strand probabilities, we prescribe a methodology for computing appropriate expected weather delays and related disruption factors for inclusion within the APCDM model. We conclude our severe weather-modeling research by conducting an economic benefit analysis using a k-means clustering mechanism in concert with our delay assessment methodology in order to evaluate delay costs and system disruptions associated with variations in probability-net refinement-based information. As a flight passes through the probability-net(s), we can generate a probability-footprint that acts as a record of the strand intersections and the associated probabilities from origin to destination. A flight plan's probability-footprint will differ for each level of data refinement, from whence we construct route-dependent scenarios and, subsequently, compute expected weather delay costs for each scenario for comparative purposes. Our second major contribution is the development of a novel slot-exchange modeling concept within the APCDM model that incorporates various practical issues pertaining to the Ground Delay Program (GDP), a principal feature in the FAA's adoption of the Collaborative Decision-Making (CDM) paradigm. The key ideas introduced here include innovative model formulations and several new equity concepts that examine the impact of "at-least, at-most" trade offers on the entire mix of resulting flight plans from respective origins to destinations, while focusing on achieving defined measures of "fairness" with respect to the selected slot exchanges. The idea is to permit airlines to barter assigned slots at airports affected by the Ground Delay Program to their mutual advantage, with the FAA acting as a mediator, while being cognizant of the overall effect of the resulting mix of flight plans on air traffic control sector workloads, collision risk and safety, and equity considerations. We start by developing two separate slot-exchange approaches. The first consists of an external approach in which we formulate a model for generating a set of package-deals, where each package-deal represents a potential slot-exchange solution. These package-deals are then embedded within the APCDM model. We further tighten the model representation using maximal clique cover-based cuts that relate to the joint compatibility among the individual package-deals. The second approach significantly improves the overall model efficiency by automatically generating package-deals as required within the APCDM model itself. The model output prescribes a set of equitable flight plans based on admissible trades and exchanges of assigned slots, which are in addition conformant with sector workload capabilities and conflict risk restrictions. The net reduction in passenger-minutes of delay for each airline is the primary metric used to assess and compare model solutions. Appropriate constraints are included in the model to ensure that the generated slot exchanges induce nonnegative values of this realized net reduction for each airline. In keeping with the spirit of the FAA's CDM initiative, we next propose four alternative equity methods that are predicated on different specified performance ratios and related efficiency functions. These four methods respectively address equity with respect to slot-exchange-related measures such as total average delay, net delay savings, proportion of acceptable moves, and suitable value function realizations. For our computational experiments, we constructed several scenarios using real data obtained from the FAA based on the Enhanced Traffic Management System (ETMS) flight information pertaining to the Miami and Jacksonville Air Route Traffic Control Centers (ARTCC). Through our experimentation, we provide insights into the effect of the different proposed modeling concepts and study the sensitivity with respect to certain key parameters. In particular, we compare the alternative proposed equity formulations by evaluating their corresponding slot-exchange solutions with respect to the net reduction in passenger-minutes of delay for each airline. Additionally, we evaluate and compare the computational-effort performance, under both time limits and optimality thresholds, for each equity method in order to assess the efficiency of the model. The four slot-exchange-based equity formulations, in conjunction with the internal slot-exchange mechanisms, demonstrate significant net savings in computational effort ranging from 25% to 86% over the original APCDM model equity formulation. The model has been implemented using Microsoft Visual C++ and evaluated using a C++ interface with CPLEX 9.0. The overall results indicate that the proposed modeling concepts offer viable tools that can be used by the FAA in a timely fashion for both tactical purposes, as well as for exploring various strategic issues such as air traffic control policy evaluations; dynamic airspace resectorization strategies as a function of severe weather probabilities; and flight plan generation in response to various disruption scenarios. / Ph. D.

We develop a detailed, large-scale, airspace planning and collaborative decision-making model (APCDM), that is part of an $11.5B, 10-year, Federal Aviation Administration (FAA)-sponsored effort to increase U.S. National Airspace (NAS) capacity by 30 percent. Given a set of flights that must be scheduled during some planning horizon, we use a mixed-integer programming formulation to select a set of flight plans from among alternatives subject to flight safety, air traffic control workload, and airline equity constraints. Novel contributions of this research include three-dimensional probabilistic conflict analyses, the derivation of valid inequalities to tighten the conflict safety representation constraints, the development of workload metrics based on average (and its variance from) peak load measures, and the consideration of equity among airline carriers in absorbing the costs related to re-routing, delays, and cancellations. We also propose an improved set of flight plan cost factors for representing system costs and investigating fairness issues by addressing flight dependencies occurring in hubbed operations, as well as market factors such as schedule convenience, reliability, and the timeliness of connections. The APCDM model has potential use for both tactical and strategic applications, such as air traffic control in response to severe weather phenomenon or spacecraft launches, FAA policy evaluation, Homeland Defense contingency planning, and military air campaign planning. The model is tested to consider various airspace restriction scenarios imposed by dynamic severe weather systems and space launch Special Use Airspace (SUA) impositions. The results from this model can also serve to augment the FAA's National Playbook of standardized flight profiles in different disruption-prone regions of the National Airspace. / Ph. D.