Thesis (doctoral)--Universidad de Guayaquil, 1983. / Includes bibliographical references.

Air traffic congestion problems in many areas of the world are well known and have been highly publicised in recent years. This airspace dilemma, which results in delays and other undesirable knock-on effects, is escalating at a phenomenal rate and requires immediate attention. Correspondingly, there is concern about safety standards in some worldwide airspace regions. In addition, it is imperative that the significant projected growth in air transport movements over the next two decades is accommodated. Thus, there is an urgent need to solve the current airspace problems and plan in a responsible manner to meet forecast demand. Solutions to these predicaments have been developed and are encompassed under the auspices of the term 'future air navigation systems'. The systems include technologies and procedures that merge to optimise the potential of airport and airspace resources so that the capacity, flexibility and safety of these resources are maximised, while delays and their operating costs are minimised. Future air navigation systems use automated communications. navigation and surveillance technologies to provide enhanced air traffic management through continuous information on aircraft positions and intention, so that reductions in separation are possible without compromising safety. However, confusion exists regarding what technologies and procedures constitute these future air navigation systems. Additionally, their current worldwide integration status is not as advanced as it should be and, in fact, remains largely unknown. Indeed, their successful introduction is far from guaranteed at present. Therefore, this research addresses these requirements by evaluating and improving implementation of tile systems on a global basis. Ultimately, this thesis provides a comprehensive analysis that discovers what systems are pertinent and whether or where they have been applied to date, in addition to developing and validating a framework strategy for improved introduction of the future air navigation systems around the world.

Intensive development of the city and efficient use of space are essential if rapidly increasing populations are to be accommodated in urban areas. Land requirements for transportation functions can be minimized by utilization of air space above transportation facilities. The problems of rapid urbanization and scarcity of land are of particular concern in the major metropolitan areas of British Columbia. British Columbia has experienced the most rapid rate of growth of any Canadian province yet most of this growth has been confined to a few hundred square miles of the province's vast area. These factors suggest utilization of air space above or below transportation facilities has particular relevance to land use and transportation planning in British Columbia. The object of this thesis is to examine the legal and legislative implications, the financial aspects and planning considerations of air rights development in British Columbia. In Chapter II, the position of air space at common law is analyzed. Statutes regulating the ownership of land and the powers of municipalities, governmental agencies and railway companies have been examined. Common law courts have ruled that air and space are not susceptible of ownership except as incidental to the use and enjoyment of the land surface or as space within a structure bearing upon the soil. The Land Registry Act and the Strata Titles Act regulate land ownership in British Columbia. The Strata Titles Act passed in 1966 provides for the individual and multiple ownership of land within an administrative framework. A critical prerequisite to strata development is that land included in the strata plan must be registered in indefeasible title as a single parcel in the name of the Strata corporation. Public and private, agencies responsible for administering highways and rights-of-way are prohibited by legislation from alienating lands that are required, therefore, air rights cannot be developed using the Strata Titles Act. It is shown that these agencies only have authority to lease interest in air space. Of all the agencies examined, none are restricted from developing air rights for their own purposes. The financial aspects of air space utilization are examined in Chapter III. Three methods of valuating air space are examined and the applicability of each is evaluated. Air rights have no real estate value if the cost of developing the air rights platform is greater than the cost of comparable land in fee simple. Air space may be utilized as a matter of public policy if long term costs and benefits show air space utilization to be economically feasible. Programs of financial assistance for air rights development are finally considered. Mortgage financing from private lenders is not readily available because of the legal implications and the traditional blighting influence of freeways and railways on adjacent urban areas. In view of the blighting influence, of highways and railways, it is suggested that provisions of the existing National Housing Act be extended to include assistance for air rights projects in conjunction with urban renewal assistance. Chapter IV outlines the planning considerations that must be recognized in air rights development. The value of determining potential air rights development areas and the methods of regulating air rights development are examined. Public ownership of air rights is the most effective method of control. Municipalities in British Columbia do not own streets, lanes, or highways, therefore, their powers of control are limited only to land that they own. Controls can be exercised over private air rights development using the zoning powers of the municipal government. Special "overlay zones" or comprehensive development provisions of most zoning bylaws can be adapted to control air rights projects. Chapter V contains the conclusions and recommendations of this thesis. Individual and multiple ownership of land is permissible through the regulations of the Land Registry Act and the Strata Titles Act. Public and private agencies controlling transportation facilities are prohibited by Statute from alienating lands required for transportation purposes. It is recommended that legislation be adopted granting powers to these agencies to participate in strata developments providing the transportation facility is maintained within the development. Extension of the Strata Titles Act to include the ownership of space would provide for easier conveyancing of air rights. Feasibility studies of air rights development must be based on the long term costs and benefits rather than on costs of comparative land for conventional development. Extension of urban renewal legislation to include air rights developments would assist in mitigating against the blighting influence of freeways and railways on adjacent urban areas. Air rights development can be most effectively controlled by vesting owner-, ship of all air rights with the municipality or city. Failing this, boards consisting of representatives from agencies owning potential air rights sites should be established to insure that maximum potential of air rights above various transportation facilities is achieved. When zoning controls are used to control air rights, special provisions should be made within zoning by-laws to accommodate air rights projects. Finally, an order of priority for use of publicly controlled air rights is suggested. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate

No description available.

No description available.

The busiest regions of airspace in the U.S. are congested during much of the day from traffic volume, weather, and other airspace restrictions. The projected growth in demand for airspace is expected to worsen this congestion while reducing system efficiency and safety. This dissertation focuses on providing methods to analyze en route airspace congestion during severe convective weather (i.e. thunderstorms) in an effort to provide more efficient aircraft routes in terms of: en route travel time, air traffic controller workload, aircraft collision potential, and equity between airlines and other airspace users. The en route airspace is generally that airspace that aircraft use between the top of climb and top of descent. Existing en route airspace flight planning models have several important limitations. These models do not appropriately consider the uncertainty in airspace demand associated with departure time prediction and en route travel time. Also, airspace capacity is typically assumed to be a static value with no adjustments for weather or other dynamic conditions that impact the air traffic controller. To overcome these limitations a stochastic demand, stochastic capacity, and an incremental assignment method are developed. The stochastic demand model combines the flight departure uncertainty and the en route travel time uncertainty to achieve better estimates for sector demand. This model is shown to reduce the predictive error for en route sector demand by 20\% at a 30 minute look-ahead time period. The stochastic capacity model analyzes airspace congestion at a more macroscopic level than available in existing models. This higher level of analysis has the potential to reduce computational time and increase the number of alternative routing schemes considered. The capacity model uses stochastic geometry techniques to develop predictions of the distribution of flight separation and conflict potential. A prediction of dynamic airspace capacity is calculated based on separation and conflict potential. The stochastic demand and capacity models are integrated into a graph theoretic framework to generate alternative routing schemes. Validation of the overall integrated model is performed using the fast time airspace simulator RAMS. The original flight plans, the routing obtained from an integer programming method, and the routing obtained from the incremental method developed in this dissertation are compared. Results of this validation simulation indicate that integer programming and incremental routing methods are both able to reduce the average en route travel time per flight by 6 minutes. Other benefits include a reduction in the number of conflict resolutions and weather avoidance maneuvers issued by en route air traffic controllers. The simulation results do not indicate a significant difference in quality between the incremental and integer programming methods of routing flights around severe weather. / Ph. D.

The Small Aircraft Transportation System, or SATS, is a NASA-led initiative that seeks to revolutionize commercial air travel by increasing accessibility and mobility for the general consumer. The hallmark of SATS is on-demand, point-to-point air transportation from one of the nation's 5,400 public use airports and landing facilities. A second-order benefit is that it may help relieve congestion on the nation's highways and at our mid- to large size airport hubs. In 1999, NASA initiated a five-year, $69 million research program to study the feasibility and viability of SATS including development of the emerging technologies necessary to make SATS a reality. The five-year plan culminated in June 2005 in Danville, VA with a highly publicized flight demonstration and exposition serving as the SATS proof of concept. The "Highways-in-the-Sky" (HITS) premise inherent to SATS is arguably its biggest enabler, and it depends heavily on the idea of free flight. HITS will potentially be the first step in moving from traditional cars and other vehicles that travel on the ground to ones that will operate largely, if not entirely, in the air. The notion of "cars" that fly was first introduced by the entertainment industry in movies and television programs decades ago. But if mankind is ever to achieve that vision, we must have a start point. This research focuses not on the economic viability of SATS but rather on the degree of flight safety inherent to a program such as this. One can easily see how the introduction of a large number of autonomous vehicles operating simultaneously in an already dense region such as the National Airspace System might carry some degree of risk. This research introduces a modeling and simulation framework that will have applications to SATS at such time as the program must be evaluated from a safety of flight perspective. That will invariably include a high degree of simulation. This work also represents the first large-scale simulation focused primarily on how SATS will perform in the out-years. / Master of Science

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Increasingly, military managers are requiring better and more efficient use of Special Use Airspace (SUA) and Military Operating Areas (MOA). To date, there has been no automated method for determining airspace utilization within the R-2508 Complex. This paper describes the development of a computer based airspace management tool called Airspace Utilization Reporting System (AURS). AURS receives aircraft beacon radar data from an air traffic control automation system used within the R-2508 Complex. The system processes this data in a customized Oracle database format and responds to query requests, making any information about aircraft activities and airspace utilization available to the user. AURS operates continuously 24 hours per day, seven days per week. The system provides a tool for near complete analysis of all transponder equipped aircraft activities and utilization information within the 20,000 square miles R-2508 airspace Complex. In this paper we also provide detailed AURS reports and examples of military and civilian aircraft activities obtained with AURS.

This dissertation contributes to the ongoing national project concerning the \emph{Next Generation Air Transportation System} (NextGen) that endeavors, in particular, to reshape the management of air traffic in the continental United States. Our work is part of this effort and mainly concerns modeling and algorithmic enhancements to the Airspace Planning and Collaborative Decision-Making Model (APCDM). First, we augment the APCDM to study an \emph{Airspace Flow Program} (AFP) in the context of weather-related disruptions. The proposed model selects among alternative flight plans for the affected flights while simultaneously (a) integrating slot-exchange mechanisms induced by multiple Ground Delay Programs (GDPs) to permit airlines to improve flight efficiencies through a mediated bartering of assigned slots, and (b) considering issues related to sector workloads, airspace conflicts, as well as overall equity concerns among the involved airlines in regard to accepted slot trades and flight plans. More specifically, the APCDM is enhanced to include the following: a. The revised model accommodates continuing flights, where some flight cannot depart until a prerequisite flight has arrived. Such a situation arises, for example, when the same aircraft will be used for the departing flight. b. We model a slot-exchange mechanism to accommodate flights being involved in multiple trade offers, and to permit slot trades at multiple GDP airports (whence the flight connection constraints become especially relevant). We also model flight cancelations whereby, if a flight assigned to a particular slot is canceled, the corresponding vacated slot would be made available for use in the slot-exchange process. c. Alternative equity concepts are presented, which more accurately reflect the measures used by the airlines. d. A reduced variant of the APCDM, referred to as \textbf{APCDM-Light}, is also developed. This model serves as a fast-running version of APCDM to be used for quick-turn analyses, where the level of modeling detail, as well as data requirements, are reduced to focus only on certain key elements of the problem. e. As an alternative for handling large-scale instances of APCDM more effectively, we present a \emph{sequential variable fixing heuristic} (SFH). The list of flights is first partitioned into suitable subsets. For the first subset, the corresponding decision variables are constrained to be binary-valued (which is the default for these decision variables), while the other variables are allowed to vary continuously between 0 and 1. If the resulting solution to this relaxed model is integral, the algorithm terminates. Otherwise, the binary variables are fixed to their currently prescribed values and another subset of variables is designated to be binary constrained. The process repeats until an integer solution is found or the heuristic encounters infeasibility. f. We experiment with using the APCDM model in a \emph{dynamic, rolling-horizon framework}, where we apply the model on some periodic basis (e.g., hourly), and where each sequential run of the model has certain flight plan selections that are fixed (such as flights that are already airborne), while we consider the selection among alternative flight plans for other imminent flights in a look-ahead horizon (e.g., two hours). These enhancements allow us to significantly expand the functionality of the original APCDM model. We test the revised model and its variants using realistic data derived from the \emph{Enhanced Traffic Management System} (ETMS) provided by the \emph{Federal Aviation Administration} (FAA). One of the new equity methods, which is based on average delay per passenger (or weighted average delay per flight), turns out to be a particularly robust way to model equity considerations in conjunction with sector workloads, conflict resolution, and slot-exchanges. With this equity method, we were able to solve large problem instances (1,000 flights) within 30 seconds on average using a 1\% optimality tolerance. The model also produced comparable solutions within about 20 seconds on average using the Sequential Fixing Heuristic (SFH). The actual solutions obtained for these largest problem instances were well within 1\% of the best known solution. Furthermore, our computations revealed that APCDM-Light can be readily optimized to a 0.01\% tolerance within about 5 seconds on average for the 1,000 flight problems. Thus, the augmented APCDM model offers a viable tool that can be used for tactical air traffic management purposes as an airspace flow program (particularly, APCDM-Light), as well as for strategic applications to study the impact of different types of trade restrictions, collaboration policies, equity concepts, and airspace sectorizations. The modeling of slot ownership in the APCDM motivates another problem: that of generating detoured flight plans that must arrive at a particular slot time under severe convective weather conditions. This leads to a particular class of network flow problems that seeks a shortest path, if it exists, between a source node and a destination node in a connected digraph $G(N,A)$, such that we arrive at the destination at a specified time while leaving the source no earlier than a lower bounding time, and where the availability of each network link is time-dependent in the sense that it can be traversed only during specified intervals of time. We refer to this problem as the \emph{reverse time-restricted shortest path problem} (RTSP). We show that RTSP is NP-hard in general and propose a dynamic programming algorithm for finding an optimal solution in pseudo-polynomial time. Moreover, under a special regularity condition, we prove that the problem is polynomially solvable with a complexity of order $O(|N / A|)$. Computational results using real flight generation test cases as well as random simulated problems are presented to demonstrate the efficiency of the proposed solution procedures. The current airspace configuration consists of sectors that have evolved over time based on historical traffic flow patterns. \citet{kopardekar_dyn_resect_2007} note that, given the current airspace configuration, some air traffic controller resources are likely under-utilized, and they also point out that the current configuration limits flexibility. Moreover, under the free-flight concept, which advocates a relaxation of waypoint traversals in favor of wind-optimized trajectories, the current airspace configuration will not likely be compatible with future air traffic flow patterns. Accordingly, one of the goals for the \emph{NextGen Air Transportation System} includes redesigning the airspace to increase its capacity and flexibility. With this motivation, we present several methods for defining sectors within the \emph{National Airspace System} (NAS) based on a measure of sector workload. Specifically, given a convex polygon in two-dimensions and a set of weighted grid points within the region encompassed by the polygon, we present several mixed-integer-programming-based algorithms to generate a plane (or line) bisecting the region such that the total weight distribution on either side of the plane is relatively balanced. This process generates two new polygons, which are in turn bisected until some target number of regions is reached. The motivation for these algorithms is to dynamically reconfigure airspace sectors to balance predicted air-traffic controller workload. We frame the problem in the context of airspace design, and then present and compare four algorithmic variants for solving these problems. We also discuss how to accommodate monitoring, conflict resolution, and inter-sector coordination workloads to appropriately define grid point weights and to conduct the partitioning process in this context. The proposed methodology is illustrated using a basic example to assess the overall effect of each algorithm and to provide insights into their relative computational efficiency and the quality of solutions produced. A particular competitive algorithmic variant is then used to configure a region of airspace over the U.S. using realistic flight data. The development of the APCDM is part of an ongoing \emph{NextGen} research project, which envisages the sequential use of a variety of models pertaining to three tiers. The \emph{Tier 1} models are conceived to be more strategic in scope and attempt to identify potential problematic areas, e.g., areas of congestion resulting from a severe convective weather system over a given time-frame, and provide aggregate measures of sector workloads and delays. The affected flow constrained areas (FCAs) highlighted by the results from these \emph{Tier 1} models would then be analyzed by more detailed \emph{Tier 2} models, such as APCDM, which consider more specific alternative flight plan trajectories through the different sectors along with related sector workload, aircraft conflict, and airline equity issues. Finally, \emph{Tier 3} models are being developed to dynamically examine smaller-scaled, localized fast-response readjustments in air traffic flows within the time-frame of about an hour prior to departure (e.g., to take advantage of a break in the convective weather system). The APCDM is flexible, and perhaps unique, in that it can be used effectively in all three tiers. Moreover, as a strategic tool, analysts could use the APCDM to evaluate the suitability of potential airspace sectorization strategies, for example, as well as identify potential capacity shortfalls under any given sector configuration. / Ph. D.

Thesis. 1975. M.Arch.--Massachusetts Institute of Technology. Dept. of Architecture. / Bibliography: leaves 50-52. / by Steven C. Hayes. / M.Arch.