Area Control Center Research Articles

Short/medium-term prediction for the aviation emissions in the en route airspace considering the fluctuation in air traffic demand

This paper proposes a novel short/medium-term prediction method for aviation emissions distribution in en route airspace. An en route traffic demand model characterizing both the dynamics and the fluctuation of the actual traffic demand is developed, based on which the variation and the uncertainty of the short/medium-term traffic growth are predicted. Building on the demand forecast the Boeing Fuel Flow Method 2 is applied to estimate the fuel consumption and the resulting aviation emissions in the en route airspace. Based on the traffic demand prediction and the en route emissions estimation, an aviation emissions prediction model is built, which can be used to forecast the generation of en route emissions with uncertainty limits. The developed method is applied to a real data set from Hefei Area Control Center for the en route emission prediction in the next 5years, with time granularities of both months and years. To validate the uncertainty limits associated with the emission prediction, this paper also presents the prediction results based on future traffic demand derived from the regression model widely adopted by FAA and Eurocontrol. The analysis of the case study shows that the proposed method can characterize well the dynamics and the fluctuation of the en route emissions, thereby providing satisfactory prediction results with appropriate uncertainty limits. The prediction results show a gradual growth at an average annual rate of 7.74%, and the monthly prediction results reveal distinct fluctuation patterns in the growth.

CARATS Open Dataの精度に関する一検討

CARATS (Collaborative Actions for Renovation of Air Traffic Systems) is a Japanese long-term vision of the future ATM (Air Traffic Management) which was planned to promote the research and development of the Japanese ATM system. CARATS Open Data released by the Japanese government in 2015 are operating data of RDP (Radar Data Processing) system actually used in four ACCs (Area Control Center) in Fukuoka FIR (Flight Information Region). Accuracy of the longitude and latitude of CARATS Open Data is evaluated by using GPS data measured in the airliner cabin. Results show that the longitude error of CARATS Open Data increases with the distance from Tokyo ACC and discontinuous changes occur when a reference radar site is handed over to another radar site. The effect of longitudinal and latitude errors of CARATS Open Data to flight parameters estimation is also studied, where it reveals that appropriate data processing is necessary to estimate parameters such as air speed and fuel flow.

Sectorization and Configuration Transition in Airspace Design

Current airspace is sectorized according to some predefined rules that are not flexible. To facilitate utilizing the airspace more efficiently, methods to design sectors need to be promoted. In this paper, we propose an undirected graph cut-based approach that employs a memetic local search-embedded constrained evolution algorithm, NSGA-II, to generate nondominated airspace configurations. We also propose a new concave hull-based method to automatically depict sector boundaries. In addition, we also study the configuration transition problem. We define the similarity of the two different configurations and calculate their similarity with a bisection diagram and a minimum cost flow algorithm. We build a forward network to represent configuration transitions across several consecutive time periods and use multiobjective dynamic programming to determine a series of nondominated configuration links from the first period to the end. We test our approaches by simulation in high-altitude airspace controlled by Beijing Area Control Center. The results show that our sectorization method outperforms the current configuration in practice, providing a lower sector number, lower intersector flow, more balanced workload distribution among the different sectors, and no constraint violations, so that the proposed approach shows its significant potential as practical applications for dynamic airspace configuration.

Robustness analysis of the European air traffic network

The European air traffic network (ATN), consisting of a set of airports and area control centres, is highly complex. The current indicator of its performance, air traffic flow management delays, is insufficient for planning and management purposes. Topological analysis of ATNs of this kind has highlighted betweenness centrality (BC) as an indicator of network robustness, although such an indicator assumes no knowledge of actual traffic flows and the network's operational characteristics. This paper conducts topological and operational analyses of the European ATN in order to derive a more relevant and appropriate indicator of robustness. By applying a flow maximisation model to the network influenced by a range of capacity reductions at the local level, we propose a new index called the Relative Area Index (RAI). The RAI quantifies the importance of an individual node relevant to the performance of the entire network when it suffers from capacity reduction at a local scale. Air traffic data from three typical busy days in Europe are utilised to show that the RAI is more flexible and capable than BC in capturing the network impact of local capacity degradation. This index can be used to assess network robustness and provide a valuable tool for airspace managers and planners.

Framework to Assess an Area Control Centre's Operating Cost-efficiency: a Case Study

Cost-efficiency is a crucial Key Performance Area (KPA) in today's Air Traffic Management (ATM) system. Traditionally, research has mainly focused on the airport domain, with little attention being paid to the operating cost-efficiency of Area Control Centres (ACCs). This paper addresses this shortcoming and develops a framework to assess the cost-efficiency of an ACC from an operational perspective. It investigates how the resources of an ACC are managed, from the start of the planning process to the day of operation. The framework develops new metrics to assess an ACC's performance. A case study is carried out on the Maastricht Upper Area Control (MUAC) centre. Results show that, despite being one of the most advanced ACCs in Europe, the human workforce is operating at only approximately 50% of their full capabilities.

The impact of controller support tools in enroute air traffic control on cognitive error modes: A comparative analysis in two operational environments

Air traffic is increasing worldwide. In order to accommodate the anticipated rapid growth in air traffic in the future, changes are required to increase the capacity of the airspace. Although major structural changes in air traffic management in Europe are still underway through the implementation of 4D trajectories, many changes happened and are happening now through the introduction of new automated features in the enroute air traffic control systems. Examples of such air traffic control features are electronic coordination and conflict detection tools designed for air traffic controllers. Although it is likely that these controller support tools may decrease the possibilities of cognitive error, the introduction of new tasks may also introduce new sources of cognitive error. This paper describes the results of a qualitative analysis conducted in two European Area Control Centers, and compares possible cognitive error modes using the TRACEr method. The results show that for an operational environment equipped with controller support tools, the cognitive errors that may occur, have changed. Errors related to detection, memory, decision-making and action execution may decrease. However, new tasks related to the controller support tools may also introduce new errors such as those related to timely detection of information. Furthermore, the results show that there is a shift in type of errors which may occur during the execution of tasks. System safety may be increased through eliminating or reducing possibilities for cognitive error, increasing error recovery opportunities and indirectly through reducing mental workload related to the execution of tasks.

New Approach for Modeling of Air Traffic Flow

<strong><strong></strong></strong> Firstly, from the strategic level flow prediction and tactical traffic flow prediction analysis of two methods of flight flow forecast, put forward by the combination method of strategic level forecast, the dead reckoning for the tactical traffic flow prediction. According to the characteristics of dynamic air traffic flow prediction, inference algorithm for aircraft trajectory conjecture by great circle track and isometric track, so as to realize the dynamic traffic prediction. Basic factors that error in in-depth study on track, according to the actual situation of Guangzhou area control center control operation, analyzes and summarizes the influence of dead reckoning uncertainty factors, proposes an equiangular track improved predictive models, and flight data is validated using actual controllers in Guangzhou, the results show that the prediction accuracy of the improved model significant improvement.

A method to estimate air traffic controller mental workload based on traffic clearances

Workload estimation is a complex domain which has been investigated extensively over the years. Past estimation techniques have focused on measuring workload directly from the air traffic controllers (ATCOs) or inferring it from traffic factors. The limitations of these techniques are interfering into the ATCO job and not being able to capture the differences amongst individual ATCOs respectively. This paper presents a novel technique overcoming these limitations, able to accurately estimate the workload experienced by the ATCO based exclusively on the clearances provided to air traffic. The technique, which was calibrated for the EUROCONTROL Maastricht Upper Area Control (MUAC) Centre, thereby has the potential to more accurately estimate actual airspace capacity. It is independent of the level of system automation and therefore applicable not only with the current ATM system, but also in the anticipated future highly automated environments as well as during the transition period. The paper discusses potential applications such as real time monitoring of operational workload and post-operations identification of sector workload imbalances. Both can contribute towards enhancing the performance of the ATM system.

Air traffic predictability framework – Development, performance evaluation and application

The performance of the Air Traffic Flow & Capacity Management (ATFCM) function relies fundamentally on the accuracy of air traffic predictability. Characterising this accuracy and assessing the potential benefits of increased accuracy is fundamental to enhance the performance of the Air Traffic Management (ATM) system and identifying areas that require improvement. This paper develops a framework to assess air traffic predictability. It validates the proposed framework with real operational data and applies it to the Maastricht Upper Area Control centre. The paper develops a methodology to assess the benefits of the deployment of enhanced predictability including capacity, resulting from improved operational concepts such as Airport-Collaborative Decision Making (A-CDM).

Small Cell Deployment and Smart Cooperation Scheme in Dual-Layer Wireless Networks

Traditional mobile networks will become dual-layer wireless networks due to small cells’ deployment. The advantages of dual-layer networks are improving network capacity and overcoming the problem of unbalanced traffic distribution in time-space domain. In this paper, performance of small cells deployment is evaluated in simulations. It is shown that users’ traffic is offloaded by small cells obviously. At the same time, performances of signal to interference plus noise ratio (SINR) and throughput are also improved. However, low SINR ([Formula: see text] dB) users are also increased because of interferences between macro cells and small cells. Furthermore, a new cooperation scheme is proposed for energy saving in dual-layer networks. This scheme is implemented through a functional modular, named by Area Control Center (ACC). Finally, simulations are given to verify the efficiency of this energy saving scheme. The numerical results show that energy consumption could be reduced by 20%.

Refresher Training for Air Traffic Controllers: Is It Adequate to Meet the Challenges of Emergencies and Abnormal Situations?

An observational field study was carried out to examine the degree that refresher training in air traffic control can account for the demands of real-world emergencies. The refresher-training exercises of 21 teams of en route controllers were observed and a number of real incidents were analyzed at a major European Area Control Centre. Expert controllers were observed handling 53 simulated emergencies and abnormal situations during their annual refresher training and their companion team resource management course. The training curriculum was found to be technically oriented. Responding to emergencies was practiced in scenarios less representative of real situations where the controllers do their job in the context of many interruptions, flight crew deviations, and unrecovered errors. Results indicated a substantial gap between formal training requirements and operational demands. An advanced safety training course is proposed on the basis of cognitive task analysis to increase the cognitive fidelity of simulations and focus on cultivating taskwork and teamwork skills.

Comparison of controller attention decrease during different break patterns in night shifts

Night shifts result in a high pressure on employees' health. Regarding air traffic control, they may also represent a safety issue. Research showed that cognitive performance is decreased at night (Monk 1996) and safety risks increase starting from the second working hour without a break (Folkard et al. 2005). Investigating a request to extend the middle part of a night shift due to little traffic, different break patterns are compared in terms of avoiding health and safety issues. 189 air traffic controllers (ATCOs) from the Eurocontrol Maastricht Upper Area Control Centre in the Netherlands were tested during night shifts lasting for 7.5 hours. During the night shift, two teams, each consisting of two air traffic controllers, were working: While one team was on break, the other took over. They were assigned to three break patterns, with four or five hours of break or a split of the night shift. Each team was tested three times during normal operation. They estimated their subjective sleepiness using a subjective measure, the Stanford Sleepiness Scale, and filled in an objective measure, the d2, to measure attention. Furthermore, one measurement took place during a regular day shift in order to control the night shift data. Results show that five hours of working without a break does not have a negative impact on attention compared to the two other work-break patterns. External validity is given, since the study was conducted during normal operation. However, it was not possible to control and evaluate all confounding variables, as this would have disturbed the ongoing safe working processes of the scheduled shifts. Therefore, future research that examines individual differences in attention and considers the different activities during the breaks of the ATCOs still needs to be conducted in order to clearly identify an optimal break pattern for night shifts. Language: en

Cognitive model of team cooperation in en-route air traffic control

Since controller teams are in charge of en-route air traffic control, team cooperation is a key issue for good control performance. We conducted ethnographic field observation at the Tokyo Area Control Center and then analyzed the obtained data to develop a cognitive model of team cooperation in en-route air traffic control. We segmented conversational records, behavioral records, and so on by control unit, and then clarified relations between the segments and identified expert knowledge and judgment behind them. Cognitive processes of controller teams were reconstructed based on a concept of distributed cognition. The analysis revealed that the mutual belief model is applicable to team cooperation processes, the role assignment of tasks within a controller team is implicit and that control plans are implemented smoothly once team situation awareness has been established. A cognitive model of controllers’ team cooperation has been constructed based on these findings.

Developments Towards Trajectory Based Operations in Arrival Management at Schiphol Airport

Air Traffic Control the Netherlands (LVNL) supports the Single European Sky ATM Research (SESAR) in the implementation of Trajectory Based Operations (TBO). A key TBO-component for LVNL is to achieve more environmentally friendly arrivals by introducing Continuous Descent Approach (CDA) in the Terminal Area (TMA) during daytime along fixed Precision Area Navigation (P-RNAV) routes. Simulations and calculations demonstrated decreased controllers’ workload and reductions in noise nuisance for use of P-RNAV routes and in fuel burn for CDA operations.To realize CDAs flown along P-RNAV routes, more predictable and stable arrival traffic flows are needed. Therefore, more accurate delivery of flights at the Initial Approach Fix (IAF) is required. LVNL is developing a decision support tool (Speed and Route Advisor - SARA) for controllers in the Area Control Centre. Simulations show that the reached accuracy of the target metering time window at the IAF can enable CDA along TMA P-RNAV routes.

Optimal maintenance scheduling of generators using multiple swarms-MDPSO framework

In this paper, a challenging power system problem of effectively scheduling generating units for maintenance is presented and solved. The problem of generator maintenance scheduling (GMS) is solved in order to generate optimal preventive maintenance schedules of generators that guarantee improved economic benefits and reliable operation of a power system, subject to satisfying system load demand, allowable maintenance window, and crew and resource constraints. A multiple swarm concept is introduced for the modified discrete particle swarm optimization (MDPSO) algorithm to form a robust algorithm for solving the GMS problem. This algorithm is referred to by the authors as multiple swarms-modified particle swarm optimization (MS-MDPSO). The performance and effectiveness of the MS-MDPSO algorithm in solving the GMS problem is illustrated and compared with the MDPSO algorithm on two power systems, the 21-unit test system and 49-unit Nigerian hydrothermal power system. The GMS of the two power systems are considered and the results presented shows great potential for utility application in their area control centers for effective energy management, short and long term generation scheduling, system planning and operation.

Evaluation of Communication Scenarios Inside the Electrical Power System

The paper presents the modelling and the dependability evaluation of communication scenarios inside the distribution grid of the electrical power system (EPS). In particular, it deals with the communication between one area control centre and a set of substations exchanging commands and signals by means of a redundant communication network. The communication may be affected by threats such as the network failure, or intrusions into the communication, causing the loss of commands or signals. Such scenarios have been modelled and simulated in the form of stochastic activity network (SAN), a particular form of Petri Net (PN), to evaluate in quantitative terms the effect of the threats to the communication. In particular, two measures have been computed: the probability and the number of failures in the communication, as a function of the time.

Collaborative, Trust-Based Security Mechanisms for a Regional Utility Intranet

This paper investigates network policies and mechanisms to enhance security in SCADA networks using a mix of TCP and UDP transport protocols over IP. It recommends creating a trust system that can be added in strategic locations to protect existing legacy architectures and to accommodate a transition to IP through the introduction of equipment based on modern standards such as IEC 61850. The trust system is based on a best-of-breed application of standard information technology (IT) network security mechanisms and IP protocols. The trust system provides seamless, automated command and control for the suppression of network attacks and other suspicious events. It also supplies access control, format validation, event analysis, alerting, blocking, and event logging at any network-level and can do so on behalf of any system that does not have the resources to perform these functions itself. Latency calculations are used to estimate limits of applicability within a company and between geographically separated company and area control centers, scalable to hierarchical regional implementations.

Air Traffic Control Complexity and Safety

“Air traffic control (ATC) complexity” can be defined as the interaction between air traffic and the sector characteristics through which this air traffic flies. Research indicates that complexity is the prime determinant of the air traffic controller's workload. Research has attempted to define and classify complexity variables that have been used to assess the capacity of en route airspace in Europe and North America. Such variables can also be used to assist in ATC sector design by highlighting those complexity factors that can lead to high workload and potentially risky scenarios for the controller. With the use of a structured interview technique, a study analyzed these ATC complexity variables for their impact on controller workload and safety. Seventy-nine air traffic controllers were interviewed about the factors that affected their workload. These controllers were based in 14 area control centers in Europe, including those of high complexity, such as Maastricht, Netherlands, as well as in nine centers in Asia, one in Africa, and Mumbai, India, a region with major traffic growth in recent years. On the basis of these interviews, a taxonomy of more than 50 complexity variables subdivided into 11 major groupings, such as traffic mix and entry and exit points, has been developed. In addition to rating of the impact of the individual complexity factors to assess their effect on airspace, interactions between complexity variables were deduced from the interviews. These interactions enable assessment of the factors that add to layers of complexity for controllers. Such a taxonomy can assist airspace planners in designing sectors that avoid complex ATC situations. How the impact of such complexity factors can be investigated in sector design is outlined.

Route-charging policies for a central European cross-border upper airspace

The introduction of the Central European Air Traffic Services Upper Area Control Centre controlling the upper airspace of several European countries allows different route-charging policies. The impact of three charging scenarios on aircraft operators is examined. It is found that, without a compensatory mechanism, the policy of having different unit rates for each air navigation service provider would adversely affect regional and region-based carriers because the unit rate of the new provider would be significantly lower than the unit rates of the national providers controlling the lower airspaces.

The Factors Affecting Airspace Capacity in Europe: A Cross-Sectional Time-Series Analysis Using Simulated Controller Workload Data

Air traffic in Europe is increasing at a rapid rate and traffic patterns no longer display pronounced daily peaks but instead exhibit peak spreading. Airspace capacity planning can no longer be for the peak period but must consider the whole day. En route airspace capacity in the high density European air traffic network is determined by controller workload. Controller workload is primarily affected by the features of the air traffic and ATC sector. This paper considers the air traffic and ATC sector factors that affect controller workload throughout the whole day. A simulation study using the widely used Reorganized ATC Mathematical Simulator (RAMS) model of air traffic controller workload is conducted for the Central European Air Traffic Services (CEATS) Upper Area Control Centre region of Europe. A cross-sectional time series analysis of the simulation output is conducted with corrections for temporal autocorrelation in the data. The results indicate that a subset of traffic and sector variables and their parameter estimates can be used to predict controller workload in any sector of the CEATS region in any given hour.