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Capacity Optimisation in TrajecTory-based OperatioNs

Periodic Reporting for period 2 - COTTON (Capacity Optimisation in TrajecTory-based OperatioNs)

Reporting period: 2019-01-01 to 2019-12-31

COTTON (Capacity Optimisation in TrajecTory-based OperatioNs) project is addressing the research topic ER3-03-2016 “Optimised ATM Network Services: TBO”, and in particular the challenge of exploring how the uncertainties associated with the agreed trajectory will impact the quality of the predictions – both volume and complexity of traffic demand – and the effectiveness of DCB processes regarding airspace management.
The main objective of COTTON project is to deliver innovative solutions to maximise the effectiveness of the Capacity Management processes in Trajectory Based Operations (TBO) taking full advantage of the available trajectory information. To achieve this goal, COTTON identifies three main sub-objectives:

OBJECTIVE 1: Improve the use of trajectory-based complexity and workload assessment to support Capacity Management enabled by Trajectory-Based Operations (TBO) including uncertainty.

OBJECTIVE 2: Identify and promote the benefits of Trajectory-Based Operations (TBO) to develop innovative demand/capacity models based on Dynamic Airspace Configuration (DAC) and Flight Centric ATC (FCA) solutions

OBJECTIVE 3: Explore Dynamic Airspace Configuration (DAC) and Flight Centric ATC (FCA) solutions integration.
In this context, COTTON has addressed the optimisation of Capacity Management processes incorporating trajectory uncertainty into an advanced model for demand and capacity balancing considering all the Capacity Management planning phases, and integrating complexity and workload algorithms more suitable to the most innovative aspects of the SESAR 2020 solutions– Dynamic Airspace Configuration (DAC) and Flight Centric ATC (FCA) –.

To achieve its objectives, COTTON has assessed the suitability of the available complexity metrics to support DAC, FCA, and integrated DAC/FCA CM process. From the result of this assessment, COTTON has selected three candidate complexity metrics, namely Solution Space, Cognitive Complexity and Geometrical Complexity. It has evolved their mathematical formulation; and developed complexity-based methods to assess capacity in DAC and FCA.

COTTON proposes a complementary use of these three enhanced complexity metrics to build COTTON Complexity Assessment, which is flexible enough to support each CM sub-process; with the due granularity to address the specificities of DAC and FCA airspaces; and effective at each planning phase.
The development and integration of COTTON Complexity Assessment within the CM processes constitutes COTTON Enhanced Capacity Management, whose potential benefits are assessed in COTTON validation.

The impact of COTTON proposed solutions on the most relevant Key Performance Areas (KPAs) has been evaluated by means of Fast Time Simulations to test not only DAC and FCA solutions in isolation but also potential alternatives for their safe integration. The validation envisages three fast time simulations focused on the evaluation of the COTTON Enhanced CM Feasibility, Capacity, Cost-efficiency, Safety and Human Performance. Specifically, it focuses on the enhancements of COTTON Complexity Assessment brought to FCA short term planning phase (one hour till the execution time); DAC short-term planning phase (day of operations up to 20 minutes before execution time) and Integrated DAC/FCA medium-term planning phase (six to one days before operations).

COTTON methodology is (depicted in Figure attached) follows the following steps:
• Firstly, COTTON identified limitations of complexity and workload metrics in DAC and FCA taking into account uncertainty prediction models.
• Afterwards, the project assessed the effects of the identified limitations to derive the requirements that complexity predictions should comply with in order to be useful in a TBO environment where Capacity Management processes are in place.
• Complexity assessment methodologies and metrics in line with the requirements previously outlined were developed.
• Once the improved complexity methodologies and metrics were available, they were integrated in DAC and FCA demand and capacity models.
• DAC and FCA improved demand and capacity models were validated through Fast Time Simulation exercises. They evaluated the appropriateness of new algorithms for DAC and FCA incorporating uncertainty in the processes of airspace organisation and segment allocation.
• In addition to the validation results, Real time experiments for integration of Human Factors were performed to guided the improvement of the complexity methodologies.
• Finally, the integration of the DAC and FCA improved DCB models was assessed and the integrated Capacity Management function (whose achievement was articulated through Milestone M5) was validated.
COTTON conducts an application-oriented research; it aims at achieving V1 (TRL2) at the end of the project by providing new operational improvements within the optimised ATM Network Services:
- DAC Capacity Management process explicitly taking into account the time uncertainty inherent to 4D trajectory planning
- FCA Capacity Management process explicitly taking into account the uncertainty inherent to 4D trajectory planning
- Traffic complexity and workload assessment adapted to Trajectory Based Operations including time uncertainty
- An overall European ATM framework for Capacity Management in TBO integrating Flight Centric ATC (FCA) into the Dynamic Airspace Configurations (DAC) concept.

The expected impacts of the application of COTTON proposed operation improvements are:
- COTTON Enhanced FCA shows an improvement of capacity when introducing the use COTTON Enhanced Complexity Metrics.
- The application of the COTTON Enhanced DAC shows better detection rates for overloads. It must be highlighted that better hotspot prediction allows for better planning of airspace configuration and more efficient use of capacity. Moreover, COTTON DAC Solution either reduces the number of sectors while keeping average OCC/min and workload within acceptable levels, or reduce/balance average OCC/min and/or workload while maintaining the number of sectors. COTTON assessed also the safety implications of the proposed DAC Solution, which brings reduced number of conflicts and conflict severity with regards to Reference DAC Solution.
- The application of the COTTON Enhanced DAC/FCA integrated solution showed that DAC alone and combination of DAC and FCA modes of operation, using dynamic allocation, is highly performant in terms of Capacity and Cost-efficiency.
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