NARSIM Simulations on Virtual Block Control and Separation Bubbles

During the last two weeks NLR successfully carried out simulations on Virtual Block Control and the use of Separation Bubbles for Taxiway Conflict Alerting under low visibility conditions. The project was carried out by AT-One, the ATM research alliance between the Dutch and German Aerospace Research Institutes NLR and DLR, for Eurocontrol, the European Organisation for the Safety of Air Navigation.
The objective of the project was to evaluate operational improvements that would support air traffic controllers in more efficiently and more safely handling airport ground traffic when visibility conditions are so bad that pilots cannot avoid collisions by looking outside the cockpit (VIS-3). Furthermore, it was assumed that there were no additional means in the cockpit that would increase pilot situational awareness, such as moving map displays.
In an earlier workshop with controllers from several European airports it was concluded that a concept for Virtual Block Control in combination with a safety net for separation (Separation Bubbles) would most probably be the most effective improvement for ground control under the specified conditions.
In order to evaluate the new tools and the associated operational procedures, the NARSIM Tower simulation environment of NLR was equipped with prototype virtual stop bars on a ground traffic radar display and appropriate alerting services for stop bar and separation violations. Rotterdam Airport (EHRD) was chosen as the geographic location as it was considered to have an ideal layout for evaluating all operational challenges when using the new tools. Above that the Rotterdam set-up was already successfully used for controller training.



Two teams of controllers (from Rotterdam and Stockholm) took part in the evaluation sessions that assessed operational procedures and, in a later stage, traffic throughput together with automation trust, impact on mental workload, situational awareness, and general system usability. Results will be reported to Eurocontrol in a final report at the end of this year. It is expected that Eurocontrol will publish that report in early 2009.

EMMA2 Airport Simulations (Milan)

In July 2008 real-time simulations for a safety assessment of the Milan Malpensa tower controller working environment were carried out with the NARSIM-Tower validation platform at NLR Amsterdam as part of the EMMA project.

The objective of the simulations was to obtain results that support a safety assessment of the Italian prototype A-SMGCS components developed within the project timeframe.



The following analysis methods were applied during the experiments:
- Observation and Improved Operational Expert Elicitation
- Insertion of Hazards in the Simulations
- Measurement of Parameters for Risk Uncertainty Reduction

Results of the real-time experiments will become available as part of the EMMA2 Validation Analysis Report at the beginning of 2009.

Requirements Engineering

Just at the start of the new year NLR finished a study for Eurocontrol investigating the role of requirements within the different life cycle phases of ATM operational concept validation as described by the European Operational Concept Validation Methodology (E-OCVM).

A survey of relevant standards (IEEE, ESA-ECSS, EUROCAE) and terminology related to operational concept validation and requirements engineering was performed. This survey resulted in a strategy for the development of requirements along the E-OCVM life cycle composed of three major processes called requirements elicitation or capture process, requirements analysis or specification process, and requirements management process.

The study describes the requirements strategy in detail and refers to the relevant standards that can be used as guidelines for the processes. An analysis of actors and their roles within the validation process emphasised the role of a central manager overseeing the development processes that lead to a gradual refinement of the requirements. Finally, the study analysed three European R&D projects regarding their requirements engineering processes and compared their approaches with the suggested strategy.

Thus, if you have lost your way in the underbrush of ATM standards and requirements documents, this study might be interesting reading material.

The report was published as NLR report CR-2007-702 and is publicly available.

What is the E-OCVM?

E-OCVM stands for the European Operational Concept Validation Methodology and is a framework that has been developed in 2004 by Eurocontrol in collaboration with several R&D partners including the ATM & Airports Department of NLR. Generally, the E-OCVM is based on the methodological approach described by the Master European Validation Plan (MAEVA) project in its Validation Guideline Handbook (VGH).

The MAEVA VGH suggests a five-step approach to validation that was originally defined in the Eurocontrol Development of EATCHIP/EATMP Validation Methodologies (DEVAM) project. As refined and expanded, these five steps form the core of the VGH. In order to address each of the steps at the appropriate level and for the appropriate audience, the VGH contains three parts, each describing the steps at different levels of detail. Despite the general acceptance of the VGH within the ATM community, several adaptations of the framework were proposed within European R&D initiatives (especially the Gate-to-Gate and C‑ATM projects) concentrating on the initial approach to validation activities and the related life cycle of the concept or technology to be validated.

Eurocontrol together with the Co-operative Approach to Air Traffic Services (CAATS) project team (responsible for co-ordinating validation approaches within the current European Commission Framework Programme) consolidated all change proposals in the first edition of the E-OCVM, which has become the mandatory methodological framework for concept validation within the European ATM community.

The E-OCVM addresses validation at the highest two levels of the MAEVA stepped approach, and additionally introduces a concept life cycle model as well as a so-called case-based approach. The latter integrates validation exercise results into key cases that directly address stakeholder issues about ATM performance and behaviours. More information can be found at the Eurocontrol Validation Forum website.