The Road to the Virtual Enterprise

The Road to the Virtual Enterprise ICT in aerospace research and development

National Aerospace Laboratory NLR - Amsterdam, April 2001

The Road to the Virtual Enterprise ICT in aerospace research and development

NLR, Amsterdam, April 2001 1

The Road to the Virtual Enterprise - ICT in aerospace research and development

The Road to the Virtual Enterprise ICT in aerospace research and development Edited by: Ir. F.J. Heerema Ir. U. Posthuma de Boer Issued by: National Aerospace Laboratory NLR Anthony Fokkerweg 2, 1059 CM Amsterdam The Netherlands April 2001 ISBN 90-806343-1-x NLR nr.: D608a 2

Dedication This book is dedicated to Wouter Loeve, aerospace engineer and ICT Division leader at the Dutch National Aerospace Laboratory NLR. Started in 1958 in aerodynamics research, he continued working in ICT from 1970. He and his division covered many of the ICT developments in aerospace research and development in the past thirty years. He always perfectly knew the direction to be taken, guided by the belief that in this field it is essential that ICT disciplines are matured in co-operation with the other aerospace disciplines and are providing for multidisciplinary collaboration. This book is composed by the ICT Division on the occasion of his retirement in April 2001.

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Contents Introduction

7

The first steps

9

ICT paves the road to the Virtual Enterprise

11

Stepping stones of the lower levels

15

SPINEware based working environments

21

Simulation: Solutions through Middleware

31

Virtual Environments

41

Interoperability in Command & Control

49

Airport operations as part of air transport

57

Air Traffic Management

71

The road to go

81

Abbreviations and Acronyms

83

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Introduction On the road to the Virtual Enterprise, looking forward and assessing trends and opportunities in Information and Communication Technology (ICT) for aerospace developments and operations, one can feel like Alice in Wonderland “I am travelling to a country that does not yet exist”. The scene of that country is exciting. New-generation aircraft, such as the Airbus A-380, the American Joint Strike Fighter and the Eurofighter are under development. The International Space Station ushers a new space era. There is a strong need to attack environmental and air traffic congestion problems. For competitive reasons companies are merging quickly into larger international entities or choose to work more closely together in consortia. And ICT has a stimulating impact on all aerospace disciplines as well as on the ability to integrate disciplines and companies into so-called Virtual Enterprises. A Virtual Enterprise can be defined as “A temporary alliance of companies, come together to share core competencies and resources in order to better respond on business opportunities and whose co-operation is supported by computer software and networks”. It presents an option to exploit opportunities and to provide products/services that no single company may be able to provide alone. Alliances of companies are not new: already in the sixties a number of aerospace projects, such as the Apollo space project, satisfied this definition. New is the intensity of the use of ICT means and the increasingly concurrent way of working of various disciplines in companies. ICT has become an indispensable discipline in aerospace, not only in the support of all the technical and administrative functions in the development and production processes, but also as an essential part of the aircraft systems and of systems for passenger comfort, of the aircraft operational support, of air transport and of environmental processes. The Virtual Enterprise concept plays an essential role in the realisation of the not yet existing country of the new aerospace developments supported by ICT for improved collaboration. On the road to a Virtual Enterprise does however not mean that one is underway to Utopia. The Virtual Enterprise is a very real world. Virtual means “having the essence or the effect but not the appearance or form of ”. One can deal with the essentials only and is not bothered by the appearance complexities.

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The Road to the Virtual Enterprise - ICT in aerospace research and development

The Virtual Enterprise concept is a result of the tools, created by ICT for in fact similar situations inside a company, and of the need to combine disciplines and/or companies for competitiveness. Both for mono-disciplinary work and for multi-disciplinary work it is important to create a single system image for the end user, showing him only the tools he needs: his toolbox or working environment. The complexities of underlying networking, operating systems, data bases, data exchange tools, etc. located on different computers, are hidden. The introduction of Computer Aided Engineering (CAE), Product Data Management (PDM), Electronic Resource Planning (ERP), Workflow management systems, and especially web-technology nowadays are changing the scene again. The collaboration of people from different national and company cultures requires hiding non-essential features such as the differences in CAE, PDM and ERP tools used. It also asks for solving new problems, as the larger security problems, emerging from the issue of information ownership and the use of internet, and the interfacing between the tools sometimes opposed by the supplier for competitiveness reasons. The various tools in the computer infrastructures of the companies can be joined together into groups of capabilities according their functionality. The common capabilities are considered as building blocks or stepping stones1, necessary to reach the Virtual Enterprise in the turbulent stream of aerospace developments. The road to the Virtual Enterprise is constructed from stepping stones from the lower level network to the application end-user programs. This book describes the various ICT building blocks or stepping stones nowadays applied in civil and military aerospace, which support the Virtual Enterprise concept. The related engineering methods are only lightly touched on. The book shortly evaluates the past in order to provide the evolutionary context. Aspects of today’s integrated aerospace ICT are described and illustrated by recent national and international projects in which NLR is involved. It is concluded with a vision on the way to go.

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Stepping-stone (Collins): – one of a series of stones acting as footsteps for crossing streams, marshes, etc. – a circumstance that assists in progress towards a goal 8

The first steps In aerospace technology and especially in aerodynamics, computers have played an important role from the time they came available. But supporting computational intensive work is quite different from supporting collaboration with computational means. Supporting collaboration requires not only high performance computers but also capabilities for secure high speed communications and standards and reliable software tools to make distributed and integrated working possible. The Virtual Enterprise as required nowadays is based on the use of ICT within the companies, as developed in the past decades. ICT developments in different companies often followed different roads, using different tools and standards, and ICT evolutions were of different maturity. The challenge is to combine these different ICT environments in such a way that the combination gives users simple and standardised access to information and facilities of the participating companies. In the sixties, computers in aerospace mainly were used to simulate physics phenomena. At the time, one of the most demanding computer applications was Computational Fluid Dynamics (CFD). CFD experts often needed to know a lot of details about the computer and the software itself, to carry out sufficiently reliable and fast simulations. In the same period computers were applied for structural computations and for the processing of measurements, for example in wind tunnels and in flight tests. It was the era of dedicated computing. In the seventies and eighties computer technologies like interactive working, graphics and visualisation and data base management were introduced for applications such as CFD, Finite Element Method computations, wind tunnel and flight testing data processing and flight simulation. The then Informatics Division of NLR concentrated on freeing the engineers from computer complexities, with as starting point that the ICT discipline should be an integrated part of the applications domains of NLR.

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Besides for simulations in aerospace research and design, computers were also introduced as parts of real time systems such as flight test data acquisition and satellite control systems. In the Netherlands the first European re-programmable satellite (ANS) was developed and NLR contributed with ground-operations and on-board computer software. In that time also a lot of software development procedures, originating from the US Apollo programs were introduced and used. It formed the basis for the ISO 9001 certification and the introduction of the Capability Maturity Model (CMM) for software in the nineties. At NLR, with geographically separated sites in Amsterdam and the Noordoostpolder, the transition to a computer network that served users in both locations became necessary. It implied that NLR had to build up experience in the area of data communication, as facilities with the required speed between both sites were not yet commercially available. Given the computer network, the first steps could be made to the integration of applications and technologies denoted as Computer Aided Design and Engineering (CAD, CAE) were introduced. Information modelling techniques were applied in the introduction of engineering data management, based on commercially available data base management systems. Together with tools for user interface management and for method management, this led to an infrastructure for information processing similar to infrastructures as striven after in industry. The nineties were characterised by involvement in design and development of complex software components and information systems for national and international industrial entities and aircraft users. A higher degree of integration by means of ICT is found in application domains as Command and Control, Air Traffic Management and Airport Support Systems. An ISO 9001 certified quality system was introduced. Activities were also further extended from the development phase to the operational phase. The experience gained with the infrastructure for information processing formed the basis of development of middleware for virtual environments. In combination with consultancy, working environments have been built for in house and external projects.

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ICT paves the road to the Virtual Enterprise Companies today are faced with an increasing need to be competitive in their product offerings to take advantage of shifting market conditions and new business opportunities. This takes place in the context of market globalisation, and a significantly reduced timeframe for decision making and the implementation of new business strategies. This has affected the role of Information Technology and its relationship to Lines of Business. Increasingly, as information becomes a strategic weapon used by companies to cope with competition, all information that is spread throughout the various business applications in different departments has to be made available in a transparent and seamless fashion to the user of this information. Like NLR, many companies have started activities to bring their ICT infrastructure on a level sufficient for distributed co-operation. On this road to the Virtual Enterprise a lot of tools and processes have still to be improved and adapted to the new ways of working, especially for higher levels of abstraction. For a long time aerospace developments have been supported by ICT. New is the fast introduction of ICT in all technological and administrative parts of the industry. It provides accepted sets of tools and ways of working for multidisciplinary and multi-site collaboration. All information in the chain of development and operations, such as information on requirements, design, production, certification and operation can be made available on computers in stead of on paper. This makes it possible for companies to access and exchange data at the same time, of course if adhering to information management and

Figure1: ICT paves the road to the Virtual Enterprise 11

The Road to the Virtual Enterprise - ICT in aerospace research and development

confidentiality rules. Fast data communication makes it possible to exchange information in near real time, allowing people in different locations to work as if sitting side by side. Figure 1 illustrates the change to a new way of working in aerospace made possible by ICT, allowing for a shorter time-to-market, reduction of costs and a flexible and customised production and operation. In analogy it is applicable for aircraft and satellite operations, air traffic control, shipyard, automobile industry, etc. The users of the collaborative companies in the Virtual Enterprise should have a well-defined access via their computer screen to the available tools and information sets, like digital mock-ups. To allow them to compose an application working environment to their specific needs, requires that the tools should be independent from each other and from the application. This so-called open systems approach to ICT Infrastructure across the Virtual Enterprise is a fundamental architectural principle that must be employed. In due consideration should be held that the defined architecture can be applied to different company sizes and business situations. It should not require large changes or investments, but should allow small and large companies with different internal ICT infrastructures and policies to communicate and to exchange information. An ICT infrastructure can be divided into groups of interrelated building blocks or stepping stones on the road to the Virtual Enterprise. Figure 2 presents such a division and illustrates some of NLR’s stepping stones. On the basis of experiences in one of the large European Extended Enterprise projects (ENHANCE), emphasis is also placed on Security and on Management Services. Especially these tools are active through all building blocks and require extra attention for inter-company collaboration Application Domains

Spacecraft

Air Transport

...

Command and Control

Air Traffic (TRADEF, SMART)

Software Development (ISEnS)

Safety and Risk Analysis (ISTaR)

Decision support (DSF)

PDM systems Workflow systems

Eurosim GEAR, SmartFED

SPINEware

XML STEP tools GUI-servers, Browsers

DBMS Reasoning Tools

HLA CORBA, DCOM, EJB

Middleware

Computer Network

Platform & Operating System Heterogeneous Computing Network Network Services

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Standardisation

Control Engineering (ISMuS)

Security services

Computational Physics (ISNaS)

Management services

Working Environments

Aircraft

Figure2: Examples of stepping stones at NLR’ s road to the Virtual Enterprise

ICT paves the road to the Virtual Enterprise

The open systems approach requires standardisation. In the area of basic infrastructure there is a noticeable amount of standardisation in that most companies are using standard products, including TCP/IP protocols for networking, Windows and UNIX type operating systems, PDM and CORBA standards for their midlleware. However, it is clear that a greater use of common IT components must still be enforced. The stepping stones in the group Computer Network ensure communications between possibly distributed and heterogeneous platforms, using network services, platform and operating system services, and a computing network to connect the platforms. Middleware decouples application specific capabilities from any dependencies on the “plumbing” layer that consists of heterogeneous operating systems, hardware platforms and communication protocols. Examples are architectures for distributed objects, basic capabilities for data and knowledge storage, user access, and for information exchange. Currently, the highest-level middle-ware deals with product and process management. NLR has developed a number of commercially available middleware facilities such as SPINEware, Eurosim and GEAR, to support main aerospace and related technical business processes Using these middleware facilities, working environments have been developed. Examples are ISNaS for Computational Physics, ISMuS for Control Engineering, ISTAR for safety and risk analysis, ISEnS for software engineering, the Decision Support Facility for the management of civil and military decision support systems, and TRADEF for the development and verification of multiradar trackers. As a next step, often common application specific models and processes have been developed and harmonised in national and international settings, to arrive at the next step in the standardisation and information exchange process. All these steps enable quick competence exchange, alignment of processes, and building of applications, by consortia and teams of a varying nature in a dynamic setting. The next chapters describe in more detail the above mentioned tools: the less standardisation, the more detail.

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Stepping stones of the lower levels The descriptions of the stepping stones in this chapter present a general state-ofthe-art in Europe. Locally, other and possibly more advanced solutions of implementations of the stepping stones may be available. Computer Network Services

The common network infrastructure of the Virtual Enterprise includes physical connections, transfer protocols and basic network services. The network provides distributed data access and interoperability within a site or between sites, within national boundaries or internationally, via private networks or via the World Wide Web. There will be demands on Quality of Service in terms of guaranteed bandwidth, transit delay and network resources, on throughput time and on reliability. With respect to transfer protocols, an Internet-based network is a low cost solution, but sufficient Quality of Service support is currently not available. Network services include file services (such as file transfer and file system cross mounting), e-mail and audio/video-conferencing. This is sufficiently standardised for the Virtual Enterprise. A platform architecture includes hardware tiers (computers) and software tiers (clients and servers). Hardware tiers, e.g. PC clients, local servers and remote servers, may be dedicated to specific functions. The software tiers may run on a single hardware platform or on multiple platforms. The client in a client/server architecture is the interface to the application. For that reason standardisation on this and the network services level will simplify all the other standardisation activities on the road to the Virtual Enterprise. Internet/Intranet defines a framework for interconnecting the networks of participating companies in a Virtual Enterprise. It provides services such as e-mail, FTP and the WWW. Web-based applications, if using standard tools, techniques and data formats, have a great potential in the realm of Virtual Enterprise. Middleware

In the past, application developers were often faced with an environment of heterogeneous operating systems, hardware platforms and communication protocols. Applications had both to be developed and to run on such an environment. A lot of effort was spent on dealing with this environment, rather than on the application itself. Early on, NLR’s ICT Division has recognised the need for an organisation-

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The Road to the Virtual Enterprise - ICT in aerospace research and development

wide solution and piloted basic building blocks for what became part of the SPINEware middleware (see next chapters). The same holds for Eurosim, GEAR and Smartfed. It shielded users from the lower level complexities. Commercial vendors now also provide building blocks for turning a heterogeneous network into a homogeneous environment. Examples of this are the Sambaserver, which allows Windows-based PCs to access files on Unix workstations, and VMware, which enables windows-based applications to run on Linux workstations, in such away that all user information is one desktop. The need for scalability has led to the evolution of three-tier (and beyond) application architectures based on component integrators such as CORBA and OLE/COM/DCOM. The separation of what once was one monolithic application into components that are deployed on three different tiers has a number of advantages. The various application components can be located where it is most cost efficient to execute them (e.g. close to the database engine), they can exploit GUI capabilities, and they can be integrated with existing applications or packaged software, etc. Applications can be enterprise-wide in scope, yet remain scaleable and capable of unifying formerly disparate Line of Business applications into what is often referred to as a single system image for the end user. Some corporations have adopted object orientation as their strategic direction. They require an infrastructure that can enable this strategy in a distributed environment, and provide them with a higher level of abstraction than traditional client/server systems. A Database Management System (DBMS) provides access to a database by one or more clients (create, define, access, change data). Many DBMSs provide access via the query language SQL (e.g. Oracle and Microsoft SQL Server). Since there are so many Database Management Systems, a Virtual Enterprise faces the problem of integrating the DBMSs of participating organisations. One solution would be to use a single DBMS. This solution is feasible if all data can be stored at one site and organisational constraints permits this approach. Another would be to use multiple databases, at one or more sites, using the same brand of DBMS, alleviating interoperability requirements. Unfortunately, a single DBMS is not always feasible, because databases in the participating companies use already different DBMSs. In such a case Database Middelware can be applied. It contains a multi-database gateway that processes requests from the clients and translates them to the target dialect of the target database.

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Stepping stones of the lower levels

A user interface provides facilities for communication between users and software. Currently most user interfaces take the form of graphical interfaces. Examples are X-Windows and Microsoft Windows and interfaces built with X-motif. With the rise of multimedia, also sound, voice, video and virtual reality will become part of user interfaces. For the use in a Virtual Enterprise, user interface services should be independent from platform and Operating System. This is the situation to a large extent, for X and for OSF/Motif. Languages that provide excellent facilities for platform independence are Java and Tcl/Tk. An interesting development is web-based user interfaces using a web browser. These are platform independent and provides the same look-and-feel on any platform. Moreover, web browsers are widely available and familiar to most computer users. Web-based applications, if using standard tools, techniques and data formats, have a great potential in the realm of VE. To support users in their work, tools have become available with which reasoning upon knowledge and data becomes more explicitly structured. Advantages are that knowledge implemented is easily showed for explanation and modification by users with domain knowledge (as opposed to ICT expertise). This enables easy sharing of knowledge between domain experts, and use of that knowledge by less proficient users, through execution of the knowledge via the reasoning tool. General-purpose reasoning tools include expert system tools such as NEXT and CLIPS; more advanced tools focus on a specific reasoning area such as constraint reasoning, or a specific application area such as diagnostics, or planning and scheduling. Work is underway to standardise knowledge representation formats. The engineering of complex products such as aircraft incorporates early inspection and simulation of behaviour. Stimulated by the US Department of Defence, a High Level Architecture (HLA) was defined for simulation re-use and interoperability. HLA has three main components: the HLA rules, the HLA federate interface specification, and the HLA object model template . When co-operating parties use different methods and tools, efficiency and sometimes even effectiveness is severely hampered if no standards have been defined for information exchange. One of the earliest standards for exchange of computer text was ASCII.

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The Road to the Virtual Enterprise - ICT in aerospace research and development

The Standard Generalised Mark-up Language SGML is a more recent development. SGML is a formal language that can be used to pass information about the component parts of a document to another computer system. SGML is flexible enough to be able to describe any logical text structure, whether it be a form, memo, letter, report, book, dictionary or database. An information exchange format based on SGML is the Hyper Text Mark-up Language HTML. Most documents on the Web are stored and transmitted in HTML. HTML is a simple language well suited for hypertext, multimedia, and the display of rigid formatted documents. The Extendable Mark-up Language XML is a simplified subset of SGML also especially designed for Web applications, but with more flexibility to formats. Digital product data must contain enough information to cover a product’s entire life cycle, from design to analysis, manufacture, quality control, testing, inspection and product support functions. STEP, the Standard for the Exchange of Product Model Data, is a comprehensive ISO standard that prescribes how to represent and exchange digital product information. In order to do this, STEP covers geometry, topology, tolerances, relationships, attributes, assemblies, configuration and more. There are interoperability concerns between the different STEP Application Protocols. Each area uses its own Product Data management methods and tools for storing and manipulating product data. Therefore, a new initiative has started to unify these approaches, viz. Unified PDM Schema, enabling PDM vendors to produce tools that can be used by a variety of developers from different areas such as structures, electronics, and airframe modellers. These standardisation effects are being co-ordinated with civil and military standardisation organisations. For an organisation supporting both civil and military customers these efforts enable affordable and standard tools to be used throughout the organisation; furthermore, co-operative activities in a Virtual Enterprise are greatly simplified. To achieve the completion of a complex set tasks such as the design of an aircraft, not only the information, but also the processes that act upon this information to produce the desired results need to be standardised and exchangedl. Workflow is the sequence of actions or steps used in a process. Workflow tools can be applied to support the process. Examples of commercial workflow tools for the latter types of application are Windchill and Enovia. These elaborate packages, that combine product data 18

Stepping stones of the lower levels

management with workflow capabilities, are being used by main aerospace industries. Security services

In a complex and multi-company environment the security policy could apply at different levels: the internal network and systems of each partner, the communication links between partners, the access “doors” to each company network, the communication software between partners (e-mail, ftp etc.), the data, the responsibilities, different national laws, etc. Each company could have different a security policy and a fundamental issue is the level of trusted relationship that is introduced between the partners companies. For Virtual Enterprises a simple way of proceeding follows these rules: – each company guarantees a basic level of security on his internal systems following his procedures and according to the internal policies; – each company applies security mechanism on the access “doors” to his internal systems following his internal policy; – common security mechanisms are applied on the communication links and software harmonising security policies and national laws. To this end stepping stones such as User identification, Perimetrical Security, Data Security, Access Control, Cryptographic Mechanisms, Anti-virus tools and Firewalls should be addressed. Firewall systems are used to avoid unauthorised connections on internal network from external network or to separate Local Area Networks with different security classification. They also allow the control of connections to external network and services from the company internal network. Typically firewalls are used to separate and secure the company network from the Internet A firewall system architecture can be composed of several elements: bastion host (i.e. the firewall itself), access router with packet filtering functions, the DeMilitarised Zone (DMZ) with systems that can be visible from the external network and used for the Virtual Enterprise. Operation and Management Services

This includes the framework for managing the assets of the Virtual Enterprise and/or the projects via which the goals of the collaboration are established. It includes process structuring management with PDM and ERP tools, configuration management tools, quality assurance (as ISO 9000 and CMM), information storage management, performance monitoring and disaster recovery. Especially in this area engineering methods for the VE are established.

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SPINEware based working environments Introduction

All activities performed under control of the ICT division are organised into a project. Typical activities in the definition phase of a project are the specifications of requirements for key personnel, tools (hardware and software), software development and test procedures, supporting tools (hardware and software), and an inventory of partial solutions already available from previous projects. The concept of a working environment has been developed to support this process and to support the execution of the project. A working environment is defined as a user-oriented, single, virtual computer (i.e. a metacomputer) that hides the details of the underlying heterogeneous network, and that may be tailored for particular end usage. NLR’s competence in working environment development is conserved in the SPINEware middleware. SPINEware is used in combination with the personal skills of NLR employees in the areas of ICT and one or more of the application oriented disciplines of NLR to enhance the engineering and decision support processes in industry and governmental institutions. SPINEware is open, Object Oriented, and set up to satisfy existing and emerging standards like CORBA. As user requirements and ICT standards are continuously evolving, so is SPINEware. SPINEware copes with this by focussing on the integration aspects of publicly available and accepted software tools, whether freeware, commercial of the shelf or elsewhere. Working environments can be extended to cross boundaries of organisations. As such, SPINEware has enabled realisation of Application Service Provider capabilities, as well as environments supporting the virtual enterprise. SPINEware evolution

In the ISNaS project - a project partly funded by the Dutch government, lead by NLR and executed by NLR, Delft Hydraulics and the Technical Universities of Delft and Twente - a working environment called ‘ISNaS’ for digital flow simulation (CFD, Computational Fluid Dynamics) was developed. ISNaS is an acronym for Information System for flow simulation based on the NavierStokes equations. In addition to development of CFD tools, the ISNaS project aimed at developing an integrated set of tools for development, application and management of CFD software and related data and documents. In the course of the project the ISNaS Shell, a graphical desk top system running on UNIX and based on the commercial product EZview, was developed. It provided the ISNaS user with a single, uniform, and user-friendly graphical user interface 21

The Road to the Virtual Enterprise - ICT in aerospace research and development

for ISNaS, presenting the CFD tools, data, and documents developed and collected in the project and available from a computer network as if these were located on a single machine. ISNaS and the ISNaS Shell raised many new ideas and new requirements. The User Shell and the information management tools, proved a suitable tool kit for constructing working environments for HPC and other application areas, for execution of several contracts, and for supporting quality assurance procedures according to ISO 9001. As the ISNaS Shell became popular within the NLR ICT division, its name was changed into “SPINE”, an acronym meaning “Software Platform for ISNaS in a Network Environment”. The meaning of the word spine as “backbone” also reflects SPINE’s main purpose: playing the role of backbone of a working environment, connecting the individual components of the system. Since SPINE was recognised to be generic and applicable to other application areas as well, the meaning of the acronym was soon changed into “Software Platform for processing Information in a Network Environment”, and later into “Software Platform for the realisation of functionally Integrated working environments in a Network Environment”. The evolution of explanations of the acronym SPINE reflects the evolution of it: from a special instantiation (basis of a CFD working environment) into a generic framework for any working environment. In addition to ISNaS as an instance of SPINE, NLR started development of several other working environments: – ISMuS for control engineering, – ISEnS, for software engineering, – ISTaR for statistical data analysis. NLR demonstrated to NEC the potentials of SPINE as valuable tool for integrating, and customising usage of, NEC’s SX supercomputers in existing (UNIX) networks. NEC decided to fund the further development of SPINE and announced SPINE as NEC program product. To obtain a world-wide trademark, it was necessary to rename the product. “SPINEware” became the product’s official name. In the course of 1997, it became apparent that a redesign of the SPINEware software was required for further extension of the functionality of SPINEware, application of modern standards (e.g., CORBA), techniques (e.g., object techniques) and tools, and dealing with modern operating systems and network architectures. Key component in the new SPINEware is the “Object Interface Layer” (OIL), which provides communication and an object base for SPINEware. SPINEware now is operational on UNIX, Linux, and Windows, and has a JAVA based User 22

SPINEware based working environments

Figure 3: View on elements of the NLR working environment for flow simulation ISNaS, illustrating SPINEware’s JAVA based User Shell.

Shell, enabling access to a SPINEware based working environment using a web browser only (Figure 3). In February 2000, SPINEware version 2.0 became the first commercially available version. Present internal use of working environments

In order to gain of the benefits of the Virtual Enterprise concepts, NLR developed working environments for internal use. These working environments can be regarded as an analogy with the Virtual Enterprise, with the understanding that the “alliance of companies” is an alliance of parties within a company. Working environments at NLR support: – R&D in development of mathematical models and methods; – R&D in application development; – competence management; – engineering in generating concepts and tools Features of working environments are: – graphical presentation of available models, tools, procedures; – hiding of network issues; – reduction of processing time by means of tool chaining.

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The Road to the Virtual Enterprise - ICT in aerospace research and development

Experience is that benefits are gained in the organisational parties involved. The benefits are: – For the individual engineer, ease of finding competence and use of it is of primary importance. – For a project team, to have a common environment supporting collaborative engineering is essential. Project working environments are easily derived from the NLR working environments, providing a flying project start, and a uniform approach to process execution. Project risks are reduced significantly, as well as process execution times. – The department benefits from the satisfaction of the employees, improved competence management as project results and experiences can easily be conserved in the working environment, and reduced training costs. – Organisation experiences increased customer satisfaction, reduced costs, and reduced risks (as its competence is less dependent on individuals). Working environment for flow simulations: ISNaS

Since its earliest development SPINEware has been applied to ISNaS, a working environment for flow simulations. At first, the working environment was aimed to support the use of flow simulation packages across a local area network consisting of a supercomputer, a mainframe, workstations and terminals. Because of its success, more functionality was - and still is - added. The development of any working environment is dominated by the following two principles: – an integrated tool has added value to the user, – the working environment shall adapt to the user and not vice versa. Hence, the user is the central theme in the development of the working environment. This theme also implies that an integrated tool does not stand alone in the working environment: it is surrounded by tools that either supply input or use the output of the specific tool. This uniform integration of several tools greatly facilitates their use. ISNaS now supports both use and development of simulation software. The use of the simulation software is supported by integrating the entire pipeline of simulation analysis: geometry modellers, grid generators, flow solvers, and postprocessors. File transfer and remote logins are hidden from the user. Feedback to the developer of the working environment is made easy by the use of electronic error reports.

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SPINEware based working environments

The development of simulation software is supported by providing for the SPINEware software version management tool, and a framework for setting up a regression test suite. Development and use of the NEC SX-5 is supported by the SX5DEV tool pack. This tool pack integrates tools for compiling, executing, analysing and debugging source on the NEC SX-5. Automatic Makefile generation allows for easy manipulation of the source. Specific options of the various tools are based on the experience of experts in the field of supercomputing. The success of the present working environment is probably best exemplified by the following. A CFD trainee was asked to perform an analysis of the complex flow of cooling fluid in a piston of a Diesel engine (see figure 4). The trainee had a thorough knowledge of flow physics, and numerical mathematics. But he was less familiar with supercomputers, networks, UNIX and postprocessing. Using the working environment he was able to perform and analyse a specific flow configuration within one week. The analysis consisted of the entire pipeline from preprocessing up to visualisation.

Figure 4: Partial view of the simulation environment ISNaS and a snap shot of the cooling fluid in a piston.

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The Road to the Virtual Enterprise - ICT in aerospace research and development

Figure 5: ISMuS: The CACE working environment

Development and user support for a specific working environment typically takes four man weeks a year. This is a small investment compared to the improved efficiency of the end users. Computer Aided Control Engineering: ISMuS

ISMuS (Information System for the development of Multi-body Systems) facilitates exchange of knowledge between various people and their Computer Aided Control Engineering (CACE) projects. Within ISMuS (Figure 5) the model developer has access to several CACE tools and behaviour and control models of dynamical systems. ISMuS acts in part as a model repository. ISMuS appears to the user as a single virtual computer. A graphical user interface provides file manipulation, tool chaining and easy program activation through point-and-click and drag-and-drop operations on icons. ISMuS is an open environment for model development: new CACE tools and models can be incorporated easily.

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SPINEware based working environments

Figure 6: The MOSAIC workflow for the transfer of model files

An important ingredient of ISMuS is the Model-Oriented Software Automatic Interface Converter (MOSAIC). MOSAIC naturally fits into the virtual CACE working environment. Integration of the model transfer process into an automatically executable workflow reduces time and effort. It eliminates repeating and boring jobs that require the same actions time and again. No time is lost with transferring model files manually from one system to the other. Working environment for software engineering: ISEnS

Integrated working environment for software engineering based on SPINEware. ISEnS provides an integrated set of tools for software development allowing for different processes and methods, such as the Unified Process and Unified Modelling Language UML. The ISEnS working environment covers the phases of the software development lifecycle from Requirements Analysis through Design, Coding, Testing, Integration, Installation and Maintenance, and implements traditional lifecycle models such as the Waterfall model, as well as Iterative and Spiral lifecycle models. The software engineer is also supported with tools for Capability Maturity Model (CMM) Key Process Areas, such as requirements management and software configuration management. Together with procedures and guidelines developed by the ICT Division’s Software Engineering Process Group, these tools provide for an integrated, cost-effective software development environment able to produce the systems that current and future customers demand.

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Figure 7: ISTAR capabilities

Safety and Risk Analysis: ISTaR

The SPINEware-based working environment for Safety and Risk Analysis ISTaR has been used within the safety projects carried out by the ICT Division. ISTaR’s (Figure 7) graphical user interface provides developers and analysts easy access to risk analysis and safety information, models, and tools. Main field of application is air transport, in particular accident risk models and tools for evaluation of safety aspects of existing and proposed new Air Traffic Management (ATM) procedures. Currently models and tools are integrated to assess collision risk between aircraft, wake vortex induced risk, navigation performance, external safety around airports, and causal safety. External use

Working environments need not be restricted to NLR itself. Using the same technology, in the NICE project the NICE HCS was built to support access to the supercomputer at NLR for the project members. The only shared facility was this supercomputer. This project was followed by the Superbroker project in which an environment was built enabling web based access to HPCN computers in the Netherlands based on SPINEware including a web based user interface. In a fourth framework programme on Multidisciplinary Design Optimisation MDO, a working environment for multidisciplinary design optimisation for civil aircraft was realised. Copies of this working environment were running at the partner sites. Working environments in which software is actually shared with other institutions, are developed in various European Union 5th Framework projects.

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SPINEware based working environments

Security is the biggest issue here (see previous chapter). In these working environments, simulation is a key element, as part of a possibly automated optimisation process. Typically these projects concern development of a complex system for which each partner has a model of one or more components. These models have to be integrated on different levels to enable simulation of the entire system: – model level: model interface definitions – software level: software interface specifications – simulation level: numerical integration; – simulator level: control and scenario execution. Besides technical issues, the issues related to proprietary rights and security have a big impact on the realisation of such distributed working environments. Approaches are: – central: integrate all models on one site, and enable access for all partners. Problem is to make proprietary information accessible. – distributed: integrate models that remain on the local sites. Problems are access, security, and performance. To deal with these different approaches, NLR is involved in the development of several simulation supporting tools: – EuroSim (hard real time) – GEAR (client server) – Smartfed (distributed HLA based) – SPINEware (distributed tool chains CORBA based) These tools are applicable pending the choice for central/distributed, real/nonreal time, HLA/CORBA. The distributed approach is a first step to the “Virtual enterprise” (see previous chapters). The centralised approach is a first step to “Application service provision”.

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30

Simulation: Solutions through Middleware From Feasibility Studies to Operations & Training

Simulation is a powerful means to mimic and study reality, ranging from the dynamics of our universe to the building blocks of atoms. On a more human scale, simulation plays a crucial part in the design cycle of products or services. Such a design cycle may start with simple feasibility studies and end with a full-scale operational training, test or research facility. With the rise of distributed networked simulation on a world-wide scale, which usually involves several enterprises, simulation also enters the exciting world of virtual enterprises. In a simulated virtual enterprise individual participants – often geographically wide apart – work together as if they were at the same location in close vicinity to each other. Simulation activities and facilities as part of a total solution concept in the area of ATM-gate-to-gate are displayed in figure 8 Individual players, e.g. aircraft, airport(s) and air-traffic-management are supported by dedicated facilities at NLR. In turn, each of these facilities is supported by simulation middleware, like EuroSim, ProSim and Gear. Moreover, as in real-life, the different players can also interact in the virtual world by proper connection. For this the exercise management tool SmartFED is used. The distributed concept makes the ATM gate-to-gate concept a special case of a virtual enterprise.

Figure 8: ATM Gate-to-Gate: total solution by distributed high-fidelity simulation

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The Road to the Virtual Enterprise - ICT in aerospace research and development

Real-time man-in-the-loop simulators are complex systems having a high demand for computing power and often require dedicated hardware. These simulators can only be developed and maintained by dividing them into several relatively simple functional components. Performance requirements may force those components to be distributed over several hosts. Middleware is a layer of distributed software that resides between the application and the operating systems network services. It provides abstractions that enable the functional components of a distributed system to co-operate by using each other’s services transparently, shielding them from technical and communication details.

Figure 9: Fitting Solutions to Application Domains

The choice of simulation middleware is made by the specific requirements of the application domain (see figure 9). Two of the determining requirements in real-time simulation usually are the simulation frequency and the interaction protocols that is used. Simulation frequencies (in 2001) are typically 30 Hz for event-driven communication, and 50-200 Hz for cycle-driven real-time simulations. On the other hand, the limiting factor in world-wide simulation through connected simulation facilities using for instance DOD’s H(igh) L(evel) A(rchitecture) is often limited by available bandwidth. In the remainder of this chapter emphasis is on the simulation middleware and their use in applications.

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EuroSim: Middleware for Synchronous Applications

EuroSim is a configurable simulator tool that is able to support all phases of space and non-space programmes through real-time simulations with a person and/or hardware-in-the-loop The design concept of EuroSim (and its ancestor ProSim ) is based on the principle that every simulator can easily be broken down into an invariant tool part and a part that is specific to the subject being simulated. By means of careful design of the tool component, i.e., EuroSim, it can be used for a wide variety of simple and complex simulators. EuroSim allows re-use of existing model software. EuroSim helps to reduce the costs associated with simulation and also allows simulation activities to be used more extensively and earlier in a program. The EuroSim consortium further develops EuroSim to access and support the international simulation community with state-of the-art simulation support. EuroSim developments are partly funded by NIVR (see also figure 10) The EuroSim consortium consist of Fokker Space, Atos Origin and NLR.

Figure 10: Marketing & Sales Promotion Posters of EuroSim illustrating both technical and organisational collaboration by the EuroSim consortium.

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The Road to the Virtual Enterprise - ICT in aerospace research and development

Figure 11: The EuroSim Simulation paradigm. The Simulation Environment is the main responsibility of NLR within the EuroSim consortium

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Simulation: Solutions through Middleware

The main responsibility of NLR is the development of an attractive EuroSim Simulator Development Environment (SDE), depicted in figure 11. The SDE will consists of a Model & Simulator Repository tool and a Simulator Composition tool. Together they will promote the (re-)use of distributed resources in aerospace system design . The Model & Simulator Repository – figure 12 – will provide the means to store and retrieve in a coherent manner all information that is relevant with respect to models. This information will include for example model code, design documentation, user manuals, and related information such as relevant session results, and proprietary information. An important asset is the availability of the MOSAIC tool as plug-in. The Simulator Development Environment is used to prepare and combine models into simulators suitable for real-time simulation in EuroSim’s run-time environment. The transfer of simulators is automated as much as possible. The Model & Simulator Repository is based on Web and database technology, allowing for a distributed repository architecture.

Repository Access (#1)

Repository Access (#2)

Repository Access (#n)

User Interface Access to

Repository Site Manager (RSM) remote RSMs

Storage Manager

Storage Manager

Storage Manager

Repository Part (#1)

Repository Part (#2)

Repository Part (#m)

View on MSR architecture (one site)

Figure 12: Top Level Architecture of the EuroSim Model & Simulator Repository

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The Road to the Virtual Enterprise - ICT in aerospace research and development

The Simulator Composition tool will be used to combine components present in the Model & Simulator Repository into an executable simulator in such a way that inclusion of hardware components later on is easy. In addition, after selection of components, the SDE will perform a check whether or not the combination of components will lead to a valid EuroSim based simulator. Gear: asynchronous applications

The GEAR middleware system is a high performance, object-oriented and realtime software system especially suited for simulations in heterogeneous environments. The GEAR (figure 13) middleware provides synchronous and asynchronous remote procedure calls, which to the software developer appear as normal function and subroutine calls. Also, subscription services are implemented to allow distributed components to subscribe to data updates from other components, allowing a flow of events and data to propagate through the system. Subscriptions have been implemented using a very efficient and reliable multicast protocol. In the aforementioned simulators, subscription services account for the majority of data communications. While encapsulating the computer and network hardware, the middleware allows access to UNIX primitives. This feature is especially useful for interfacing with graphical user interfaces, third party products and the outside world, such as other simulators. To assist the user of the GEAR middleware, advanced libraries have been developed. Distributing components can be achieved with only a few lines of application code, significantly reducing realisation and maintenance costs and also contributing to the uniformity of the components and the simulation system as a whole. For assistance of both end users and software developers, the GEAR middleware is fitted with advanced monitoring features. A supervision module provides insight into the components involved, their diagnostics and the current simulation time. It also offers controls for pausing, speeding up and slowing down a simulation. A distinguishing feature of the GEAR middleware is its distributed monitoring facility, which allows users to call up textual representations of distributed objects. If an object contains references to other objects, they can be accessed through hyperlinks. Simple interfaces combined with these distributed debugging and monitoring facilities have greatly reduced the usual disadvantages of distributed software systems.

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Figure 13: Architecture of an application using the GEAR middleware, illustrating also the significant role of generated code

The GEAR middleware is highly efficient. The event-driven model in combination with multicast functionality and thin layers supply virtual instantaneous response, imperative for real-time man-in-the-loop systems. For developers the simplicity of the interfaces and the high-level of abstraction provide for a short learning curve and efficient component development. The same characteristics contribute to high portability of components to other (middleware) platforms. Recently GEAR has been used in a series of real-time simulations with up to 75 active participating components and 30 human participants, illustrating its high scalability. The open architecture of GEAR enables simulators to easily join a federation of simulators, also called a distributed simulation. The distributed way in which simulation control is implemented, guarantees that federates (i.e. simulation entities) implemented on top of GEAR can act both as master and slave in a distributed simulation.

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Figure 14: Exercise Management of Networked Distributed Real-Time Simulations with SmartFED. SmartFED: Distributed Exercise Management

NLR has developed an HLA-based software tool, SmartFED (Scenario Manager for Real-Time FEderation Directing) to cope with the challenges of managing the distributed responsibilities of multi-site networked real-time simulations. SmartFED is a facility to couple various autonomous, geographically dispersed real-time (legacy) simulators into one distributed real-time simulation . In HLA parlance, such simulators are called federates. Federates collaborate in a federation to achieve the distributed simulation. SmartFED manages the distributed responsibilities of the federation, whereas each federate remains responsible for its own internal affairs. As such, SmartFED supports the HLA Federation Development and Execution Process (FEDEP) Model. The result is a single controlled distributed real-time simulation. The HLA-compliant SmartFED tool encompasses three modules that together enable exercise management (see figure 14) 1. The Federation Manager: for exercise initialisation and run-time control of the execution state of all federates in the federation. 2. The Federation Monitor: for (real-time) exercise monitoring, visualisation and analysis. Support for after-action review is also provided. 3. The Scenario Definition and Execution Manager: for exercise planning by execution of pre-defined scenarios. These scenarios specify for instance when to generate certain events during simulation execution. 38

Simulation: Solutions through Middleware

SmartFED provides the means to combine single simulation facilities into a powerful total solution virtual facility for specific applications, both inside and outside the aerospace domain. SmartFED has been successfully used as an indispensable core element in several other programs, from its inception in 1996 onwards. The part of SmartFED that controls the simulation has successfully been adapted for CORBA applications. Mission Preparation and Training Equipment: MPTE

From the early beginning space research has been an effort in which many companies and institutes co-operated. Not surprising, rudiments of virtual enterprises are apparent in this realm long before the term was invented. Take for example the Astronomical Netherlands Satellite (ANS), launched in 1974. Its operations involved the Operations Centre of ESOC, Darmstadt (Germany), the ESTRACK Ground Station at Redu (Belgium), a large number of NASA ground stations all over the world, and the ANS Experimenter’s Processing Centre (EPC) in Utrecht (The Netherlands). True, the technology of data communication was primitive by today’s standard: telex lines, telephone lines and magnetic tapes. Still, the idea of a virtual enterprise (or perhaps a virtual organisation) was there.

Figure 15: Simulation for ERA mission preparation 39

The Road to the Virtual Enterprise - ICT in aerospace research and development

A recent example of a Virtual Enterprise in space research using simple data communication methods is the Mission Preparation and Training Equipment (MPTE) for the European Robotic Arm (ERA), figure 15. MPTE involves a number of space research institutes: ESTEC in Noordwijk, The Netherlands, the Russian Rocket Space Corporation/Energia and the Russian Gagarin Cosmonaut Training Center, both in Russia. Therefore, the data communication must be accomplished by taken both Russian and Western infrastructure into account. The Mission Preparation and Training Equipment (MPTE) is a ground based information system (hardware and software), supporting the preparation, simulation, validation, verification and on-earth monitoring of ERA missions, figure 16. ERA is the European Robotic Arm that will be placed on the International Space Station (ISS). Besides that, MPTE supports the training of cosmonauts in the execution of ERA missions and the evaluation of executed ERA missions.

Figure 16: MPTE: Co-orporation between the virtual world and the real world.

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Virtual Environments The NLR Information and Communication Infrastructure

To perform its mission in supporting industry and governmental agencies it is essential that the NLR has the possibilities to be part of each possible Virtual Enterprise in aerospace. So the NLR Computing Network, the Information and Communication Infrastructure (ICI), supports the various aerospace disciplines in their collaboration with industry and public and private operators and organisations. The NLR Information and Communication Infrastructure has been developed as being part of aerospace projects. In a multi-disciplinary, multi-site organisation like NLR, it is important that data and software is equally available to all employees. This has led to an internal Local Area Network where in principle every connected computer can be reached from every working location. For pragmatic reasons, the main central compute and data servers have always been located in the site Noordoostpolder. Emphasis has been placed on a sufficient high speed connection (155Mbps) between the two main NLR sites, with the intention that an employee in Amsterdam should not be hindered by the distance between his workstation and the central servers. Internal speeds are up to 100Mbps; a 1Gbps port links the NLR network to national and international networks (figure 17).

Figure 17: NLR Information and Communication Infrastructure 41

The Road to the Virtual Enterprise - ICT in aerospace research and development

Within the need-to-know constraints of the NLR security policy, the Informatics Division of NLR encourages an open attitude to the sharing and reuse of information and for that reason information is stored at central servers and in working environments. The working environments are centrally maintained, but are available for distributed use. Personal Computers and RISC workstations of various brands and with various operating systems have been made interoperable. The internal NLR network is standardised on the TCP/IP protocol layers. Functions of a central compute server and a central data server are implemented on separate servers, such that the development of both functions is separated. Standard file access protocols like NFS connect the data server to other servers and Unix workstations irrespective of their operating system. The basic layout of the network enabled a situation where an employee can use his data and software from every single workstation at NLR. The stepping stones indicated in figure 2 are available in the NLR ICI. Besides the support of the whole ICT Division to these stepping stones, the ICI Virtual Environment especially supports: – Network Services: The NLR ICI is based on the TCP/IP protocol. The topology of the network is such that all NLR users of the ICI can contact and use all necessary servers. – Platform and Operating services: The NLR ICI contains servers that are useful for all types of NLR activities. The servers range from Windows-based servers to powerful UNIX compute servers like the NEC SX-5 supercomputer. – Middleware: Windchill PDM, SPINEware and various Web browsers. – Security Services: By means of strict user authentication, password protection, password ageing, and access control lists, all data stored into one of the central servers is protected against unauthorised access. The communication between the NLR infrastructure and the rest of the Internet is protected with state-of-the-art firewall technology. For more close co-operation with (international) partners and customers, as in an Virtual Enterprise, a specific part of the ICI has been set apart as a so-called “Demilitarised Zone” (DMZ). This DMZ is an integral part of the ICI, when approached from within NLR. Systems within the DMZ are reachable from outside NLR, but it is not possible to reach NLR-internal servers from a server within the DMZ.

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– Operation and Management Services: The operation of the NLR ICI is based on a documented set of procedures and is ISO9000 certified. Trend analyses are made on the most critical issues of the network in order to respond proactively on the determined growth of the use of the infrastructure. The endto-end availability of the infrastructure is measured regularly and measures are implemented to improve the availability. Enhanced Aeronautical Concurrent Engineering: ENHANCE General

With respect to Virtual Enterprises in general, in the European aeronautical industry the Enhanced Aeronautical Concurrent Engineering (ENHANCE) project is considered as today’s main initiative deployed, by defining a new common way of working, with related operational development tools, engineering methods and organisational guidelines for joint European aeronautics product development. Main impacts expected are reduction of development lifecycle development time and costs, increase of competitiveness and a strong European presence in the adoption of standards. The ENHANCE project aims at providing Concurrent Engineering methods and tools for the whole aircraft industry, including airframes, engines, equipment, helicopters, aeronautical research centres, airlines and SME suppliers. It groups 53 partners, among which are 14 contractors: EADS (Aerospatiale, DASA and CASA), BAE, Dassault Aviation, Alenia, Eurocopter, Rolls-Royce, SNECMA, MTU, Sextant Avionique, Messier-Dowty, Liebherr and NLR. This complete industrial view will minimise fragmentation and therefore accelerate the establishment of global engineering standards. Recent practical experience in Concurrent Engineering is combined with relevant state of the art Information Technology. ENHANCE covers all fields of the development and support process. Workpackages, in itself large projects, deal with Lifecycle and Business Management (contracts, administration, programme management, development process model), with Product Engineering (Digital Product Models, standard parts, aircraft support, certification, scientific calculation), with Technology and Methodology for the Extended Enterprise (standards for exchange of information, multi-site collaborative work, information technology infrastructure, training), with Innovative IT, with Concurrent Engineering Integration and Experiments, with Business Case Studies, with Human Factors and Concurrent Engineering Support and with Dissemination.

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The Road to the Virtual Enterprise - ICT in aerospace research and development

One of the main responsibilities of NLR is the introduction of Innovative IT. The main goals defined by industry are: – Illustrate how partners within a Virtual Enterprise with different Workflow Management Systems can collaborate on a common, but distributed business process, – Illustrate a collaborative environment in which members of a Virtual Enterprise will interact on internationally distributed, heterogeneous data: navigation through distributed databases, – Enable reliable, flexible, secured business quality communications between partners of the Virtual Enterprise over the Internet. Workflow system

The main objective of the workflow management illustrator is to show how aeronautical companies can improve their co-operation, process control and communication within their companies as well as over different facilities and countries. The workflow management illustrator will integrate pieces of Internet and workflow technologies in order to demonstrate how the integration can provide new capabilities to the aeronautical business processes that no piece of technology could provide separately. The final goal is to demonstrate how independent workflow management systems from different vendors can co-operate on a common business process that is being distributed across distant sites. In this illustrator workflow functions from the Windchill, KPM and SPINEware are used. As participants of the future common Concurrent Engineering business process intend continuing to use the workflow management system adopted by their company, interoperability of workflow systems remains a critical IT issue for interconnecting business processes. This issue has been recognised and organisations that deal with workflow management technologies have joined within the Workflow Management Coalition to draw up standards related to interoperability of distributed and heterogeneous workflow management products. Within the workflow illustrator aspects of these proposed standards have been deployed and it is shown how new workflow management technologies, combined with internet technologies, are used to enable current workflow systems to communicate with each other at run-time. The workflow systems are invoked either by web clients or by another workflow system.

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The Road to the Virtual Enterprise - ICT in aerospace research and development

One of the main responsibilities of NLR is the introduction of Innovative IT. The main goals defined by industry are: – Illustrate how partners within a Virtual Enterprise with different Workflow Management Systems can collaborate on a common, but distributed business process, – Illustrate a collaborative environment in which members of a Virtual Enterprise will interact on internationally distributed, heterogeneous data: navigation through distributed databases, – Enable reliable, flexible, secured business quality communications between partners of the Virtual Enterprise over the Internet. Workflow system

The main objective of the workflow management illustrator is to show how aeronautical companies can improve their co-operation, process control and communication within their companies as well as over different facilities and countries. The workflow management illustrator will integrate pieces of Internet and workflow technologies in order to demonstrate how the integration can provide new capabilities to the aeronautical business processes that no piece of technology could provide separately. The final goal is to demonstrate how independent workflow management systems from different vendors can co-operate on a common business process that is being distributed across distant sites. In this illustrator workflow functions from the Windchill, KPM and SPINEware are used. As participants of the future common Concurrent Engineering business process intend continuing to use the workflow management system adopted by their company, interoperability of workflow systems remains a critical IT issue for interconnecting business processes. This issue has been recognised and organisations that deal with workflow management technologies have joined within the Workflow Management Coalition to draw up standards related to interoperability of distributed and heterogeneous workflow management products. Within the workflow illustrator aspects of these proposed standards have been deployed and it is shown how new workflow management technologies, combined with internet technologies, are used to enable current workflow systems to communicate with each other at run-time. The workflow systems are invoked either by web clients or by another workflow system.

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Navigation through distributed data bases

The objective of the navigation illustrator is to demonstrate a standards based, collaborative environment in which geographically dispersed members of a virtual enterprise will interact with heterogeneous data, which may have originated from other parts of the enterprise. Users are enabled to simultaneously share ideas, resolve problems and evaluate and exchange information as well as contributing to product development by adding value to product data according to their role. The architecture of the navigation illustrator is based around the concept of a single view on engineering data, from whatever source, with the ability to modify the source data from the single view. An end-user of the system needs to transparently obtain, work with and return data to the Product Data Management (PDM) systems; he should not concern himself with the detail of where the data is actually stored or how the system manages the data. Furthermore, the user requires access to structurally dissimilar data originating from a variety of disciplines - heterogeneous data. A particular company may choose to store for example CAD data in one location and CFD data in another, and manage both data sets through its own PDM system. Another company, possibly with other tools, may do the same for another part of the product. Nevertheless, all data sets are representations of information about a single product, and the user is required to view the product in its entirety, despite the heterogeneity of the tools and the data, and the distribution of the data. Thus, not only access to the heterogeneous data is required, but also a method of collating its component parts into an integrated whole and presenting it in a form meaningful to the user. Figure 18 presents an overview. So, as well as obtaining data from different, distributed PDM systems, the data has to be presented to the end-user in a format that suits his role in the process.

Figure 18: The architecture of the navigation illustrator

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In the navigation illustrator, there will actually be two “Virtual Reality” environments: a high-end Virtual Reality environment (dVISE and ICAD) which allows for viewing and changing of data, and a low-end Virtual Reality Model Language (via a web-browser), which only allows for viewing of data. In the high-end representation will be an interface that allows intuitive manipulation of the model, with the ability to update the model from the Virtual Reality environment. Secured networking

Communication is not only the heart of Concurrent Engineering but the heart of business and the Internet has become the star of the communication. But Internet itself does not enable reliable, secure and quality communications between partners The public nature of the Internet heightens the security concerns that exist to some extent on any Wide Area Network. The risks associated with user authentication and unauthorised access to sensitive data have been recognised for years. Concurrent Engineering Business requires a mobile workforce and virtual teams, which members (scattered throughout partners) need to exchange data at any time, to co-ordinate their work, and to quickly attack a particular problem before being disbanded. Networking technologies have to meet this flexibility while keeping the telecommunication charges reasonable. By moving to the Internet, the extended enterprise is reachable all over the globe. A Virtual Private Network (VPN), typically uses the Internet as the transport backbone to establish secure links between business partners, extends communications to regional and isolated offices, and significantly decreases the cost of communications for an increasingly mobile workforce. In order to address the change in relative risk levels, and to answer concerns regarding Internet use in general, a new standard - the IPSec protocol - provides new security mechanisms that build security in the network itself. Creating secure, private corporate networks using the shared infrastructure of the Internet is the new promising technology called Internet-based virtual private networking. The secured networking illustrator (figure 19) focuses on the possibilities and limitations of the innovative protocol IPSec. IPSec is not innovative in the sense that this protocol is not yet implemented, because there are already a number of products that support IPSec. The protocol IPSec is innovative in the sense that in the present state and situation it is rarely used by enterprises.

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Figure 19: The secured networking illustrator

The secured networking illustrator applies IPSec in three scenarios: – Virtual Private Network scenario; this scenario simulates a virtual enterprise between the private networks of three enterprises. Secured tunnels are created between those enterprises over the Internet. – Remote access scenario; this scenario demonstrates secured access to the private network of the enterprise from any place on the globe. The traditional way to provide such access is to set up a long distance telephone connection to the private network of the enterprise. Within this scenario is demonstrated that a secured connection can be set up to the private network of the enterprise by using a local telephone connection to the nearest Internet Service Provider, and from there access the company’s network over the Internet. – Protecting a sensitive server; this scenario will show end-to-end security between a client and a server system over the Internet. Superbroker

Tools are developed that make it possible for NLR to act as Application Service Provider by giving customers access to working environments of NLR. One of the tools is Superbroker that facilitates access to NLR resources as to the NLR Supercomputer NEC SX-5, via a common WEB browser. The Superbroker facility has been used successfully for a real-time simulation (including computational steering) of an air curtain air conditioning system. Using the Superbroker such complex simulations are available to anyone with access to the Internet. 47

The Road to the Virtual Enterprise - ICT in aerospace research and development

48

Interoperability in Command & Control ICT and Command & Control Information Systems

Command and Control Information Systems are the facilities, equipment, communications, procedures, and personnel essential to a commander for planning, directing, and controlling operations of assigned forces pursuant to the missions assigned .In short this type of systems are called C2 systems or C2IS. Various other shorthand names are used, in the context of this contribution the above mentioned short hands will be used. National Aerospace Laboratory NLR has been involved in the development of C2IS from the nineteenseventies. Information and Communication Technology (ICT) is the main technology found in C2IS. By consequence the ICT Division of NLR has played a leading role in development and fielding Resulting systems are used as operational system by the Royal Netherlands Airforce (RNLAF) for the support of their day by day operations (figure 20). Application of the resulting systems was and is still mainly in the support of activities at airbase and/or at squadron level. Nations seeking to enable information exchange among international military coalition partners face several tasks for laying the groundwork for vital interoperability for operations that may be several years in the future. These efforts involve individual national commitments to build interoperability into their own C2 systems and Figure 20: RNLAF operations practices. To deliver interoperability within a certain service is a hard job, the difficulty increases among different services within a single nation. Not to mention the complexity with interoperability among different nations. Items such as standards, security and cost-bearing all weigh heavily on efforts to take the international steps. The ideal situation would be as C2 systems from different nations and services could operate as an Virtual Military Enterprise. In this military context, where the notion of Enterprise is found in “coalition”, the ideas and technologies mentioned in the first section of this publication are decisive for success. Within NATO there is a trend towards integration which is supposed to end in an integrated capability in C2IS. This capability will include existing systems as well as new systems. Standardisation of data exchange formats and system internal data structures play an important role for interoperability and integration. 49

The Road to the Virtual Enterprise - ICT in aerospace research and development

While standards do help, they are not the final answer. A C2 system may comply with accepted standards, but at the end it must be demonstrated in a test environment. The NLR ICT participation in interoperability efforts are found in contributions to the definition of the NATO C3 Interoperability Environment Testing Infrastructure study and to the interoperability trials within NATO Joint Warrior Interoperability Demonstration. NATO C3 Interoperability Environment Testing Infrastructure study

NLR participated in the Netherlands’ contribution to the NATO C3 Interoperability Environment Testing Infrastructure study in co-operation with TNO-FEL. The Aim and Scope of the studies undertaken by the NATO C3 Interoperability Environment Testing Infrastructure (NIETI) Project Team (NIETI PT) between February 1999 and July 2000 were defined as: The Aim of the NIETI project is to provide an integrated testing infrastructure of NATO and national testing facilities to support NATO and multinational testing of systems, products and standards, in accordance with the Council approved NATO Policy for C3 Interoperability. One of the aspects of the NIETI Project is to be an essential supporting element of NATO C3 Interoperability Environment (NIE) specified in the NATO Policy for C3 Interoperability, which includes the support to testing of standards and products, and systems interoperability testing, such as operational evaluations, field exercises (e.g. Combined Endeavour) and interoperability demonstrations (e.g. JWID). Joint Warrior Interoperability Demonstration trial

An environment to conduct interoperability trials within NATO context is JWID. JWID (Joint Warrior Interoperability Demonstration) is an annual event where experts from the industry/ public sector and warfighters are brought together and off-theshelf and new/evolving technologies are demonstrated that solve Command and Control, Communications, Computer, Intelligence, Surveillance and Reconnaissance (C4ISR) interoperability issues for joint and combined warfighters. Figure 21: Joint Warrior Interoperability Demonstration JWID’00-‘01

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Interoperability in Command & Control

NLR participated in JWID ’00 (Figure 21). In close co-operation with the Dutch Ministry of Defence (MoD) and the Royal Netherlands Air Force (RNLAF), NLR demonstrated the interoperability of ICC and OMIS-2. ICC is the Initial CAOC Capability (recently renamed to Integrated Command and Control). This system is developed by NC3A and is in use at ICAOCs (Interim Combined Air Operations Centers) as the predecessor of ACCS, the NATO Air Command and Control System under development. OMIS-2 is the modernised Operations Management Information System. OMIS-2 is developed by NLR and operational at Volkel Air Force Base. The systems were connected with each other via a prototype interface which has been demonstrated during JWID ’00 against an operational war scenario as background. The main objectives of NLR to participate in JWID ’00 were: – Gain experience in operating in a NATO environment. Experience in this environment is valuable for future military work, possibly also in ACCS context. – Demonstrate the interoperability capabilities of OMIS-2. One of the requirements for OMIS-2 as to add interoperability capabilities. This was accomplished by the re-design of the data model and use the ATCCIS (Army Tactical Command and Control Information System) standard as guideline. JWID offered a good opportunity to demonstrate the interoperability capability. OMIS2

OMIS is the Operations Management Information System which is in use by the Royal Netherlands Air Force (RNLAF) at Volkel Air Force Base in The Netherlands since 1983. OMIS is a command and control (C2) system which has as main goal to support the RNLAF in its task to prepare aircraft for missions to be flown. OMIS assists in the communiAircraft Alertmessages cation of all necessary information between Reporting different control centers AIRSTAR LOGSITAIR Tasking and units at an Air Force ATO MISSION ATM Base and provides all usTotes ers with consistent and Pilots up to date information, ETD needed to perform their ATD ETA task. A schematic overATA Fuel Weapons view of the OMIS functionality is shown in Figure 22: Overview of OMIS functionality figure 22. 51

The Road to the Virtual Enterprise - ICT in aerospace research and development

OMIS assists in keeping up to date the information on and allocation of resources such as aircraft, fuel, pilots, and weapons. Air Task Orders and Air Task Messages are processed and communicated as well as Reports to higher command levels. Air Traffic Control information on planned and actual times of departure and landing of aircraft are registered. Changes in Alert Status are distributed to all connected units right after they arrive. A variety of reasons made a necessary to modernise OMIS, which led to OMIS2. General approach during the modernisation of the software was to apply as much as possible Commercial Off The Shelf (COTS) software products to meet all requirements. Hardware and operating system specific features were avoided completely. Requirements that couldn’t be met by the application of COTS products alone were satisfied by implementing missing capabilities on top of the COTS products using COTS available development tools and by tailoring parts of the COTS software products. A new requirement for OMIS-2 is the capability to interoperate with other C2 systems. For OMIS-1 there was no such requirement and therefore this system lacked capabilities to interoperate. At application level this requirement resulted in a complete redesign of the data model. The ATCCIS (Army Tactical Command & Control Information System) standard data model was used as basis for the new data model. All entities in the OMIS-2 functional environment were reanalysed, normalised and placed in a so-called ATCCIS-able data model. Adoption of the ATCCIS concept facilitates future coupling with other national and possibly international Command and Control systems that are based on the ATCCIS model Application of the Oracle Relational Database Management System provided the facilities to implement the new data model. At network level the interoperability requirement was met via the application of standard network hardware and software. The re-hosting resulted in a system with a 100 percent equal functionality, but based on leading edge technology and with improved capabilities for future extensions and an improved ease of operation and management. Mid 1999, OMIS-2 has been installed and made operational at Volkel Air Force Base in the Netherlands. The network configuration consists of multiple servers placed at secure locations, and client workstations all over the base. Figure 23. Gives an impression of the client-server configuration, in which all user interface related functionality is performed by clients and data management activities mainly by the server(s).

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Figure 23 OMIS-2 client-server network ICC Integrated Command and Control

The Combined Air Operations Center (CAOC) is one of the main NATO entities which support the operational and tactical command and control of air forces assigned to NATO in peace, crisis or war, and for exercises. The CAOC performs all air mission planning and tasking, and co-ordinates with land and maritime forces within designated area of responsibility. It also monitors the current situation, performs appropriate re-tasking and supervises the activities of the Air Operations Control Station (AOCS ). ICC is an integrated C2IS environment that provides information management and decision support to NATO CAOC level air operation activities. ICC was developed by the NC3 Agency, tasked by SHAPE with a project comprising of two elements: – to investigate functions and technologies anticipated for the NATO Air Command & Control System (ACCS) program and to evaluate their operational utility in order to improve the future ACCS. – to support development of the interim capability requirements until ACCS becomes available. After successful trials during major NATO exercises throughout Europe, the system has been installed for operational use in several ICAOC’s in the NATO Northern, Central and Southern region as part of their AOPTS (Air Operations Planning and Tasking System) initiatives, and is being interfaced with national systems. Various other sites and NATO nations have decided to adopt Integrated Command and Control as their interim capability for national Air Operations Centers. The ICC provides functional support for the most critical Air Command and Control functions at the CAOC level, such as Planning & Tasking, Air Task Order (ATO) / Air Task Message (ATM) generation, and Current Operations (Offensive section). It runs on commercial-off-the shelf UNIX workstations, a relational database and a modern graphical user interface. 53

The Road to the Virtual Enterprise - ICT in aerospace research and development

Interoperability OMIS-2 and ICC

At Volkel Air Force Base, OMIS-2 currently operates as a stand-alone system. For the daily operations, when the flight plans are determined by the squadrons, this suffices. During exercises however, the tasking comes from CAOC Kalkar via ICC (there is one ICC remote station located at Wing Operations Center). All Air Task Messages have to be entered manually in OMIS-2. Similarly, status and result codes from OMIS-2 have to be entered manually in ICC for reporting purposes. This swivel chair -interface is very inefficient and error sensitive. The NLR has built an interface between ICC and OMIS-2 that automatically inserts Air Task Messages, received from ICC, into OMIS-2 and sends mission status reports back from OMIS-2 to ICC. This interface relieves the operators at the Wing Operations Center from the tedious typing and provides CAOC immediate insight in the status of the operations. A prototype of this interface was demonstrated at JWID ’00. To increase the attractiveness of the demonstration, Dutch forces were incorporated into the scenario to be able to demonstrate the interface against an operational background. The three squadrons from Volkel Air Force Base were virtually stationed at Birmingham International Airport in Michigan, US. The squadrons participate in the air operations and a sequence of missions is defined within the scenario. To emphasise the operational character of the demonstration, operational support was give by the Royal Netherlands Air Force in the preparation of the demonstration scenario. To be able to give a good impression of the activities performed with OMIS-2 at the Air Base, a small but representative OMIS-2/ICC configuration was brought to SHAPE. With this configuration the main stream of operations, necessary to execute the missions, were demonstrated. The configuration consisted of one SUN Ultra 10 workstation and three Compaq PCs. The SUN was used as client and server for ICC. One PC was used as OMIS-2 server and (wing) client. The other two PCs were used as (squadron and ATC/tower) clients. The demonstration set up during JWID’00 is presented in figure 24. At the start of the demonstration an ATO is released in ICC and the ATMs for the missions defined in the ATO are sent to OMIS-2. In OMIS-2 the further processing of the missions is performed. At Wing level the mission is handed over to a squadron. At squadron level the resources (aircraft, pilots and crew chiefs) are allocated to the mission sorties and the configuration of the aircraft are defined. At Air Traffic Control level (the tower) the sorties are declared airborne upon departure and landed at their return on the base. 54

Interoperability in Command & Control

Finally, reporting data is entered in OMIS-2. While all these actions are performed using OMIS-2, CAOC is kept informed about the mission through status reports sent by OMIS-2 to ICC. These reports include take-off/landing times, mission status, result/cancellation codes and the successfulness of the mission.

Figure 24: Demonstration set up

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56

Airport operations as part of air transport Airport support systems

Due to the rapid growth of air traffic, many of the world’s busiest airports are operating at their capacity limits. In 1998, out of 111 major airports of the world, 21 were operating near saturation for most of the day. A further 65 were operating near saturation at peak hours. Airport congestion is becoming a serious constraint, adversely affecting overall ATM service capacity as well as negatively affecting the airport environment. As traffic densities on airports grow further, there may also be safety effects, unless precautions are being taken. Therefore, the current situation that airport ATM-related operations have never been fully integrated into the overall ATM organisation will have to change. Measures being taken to alleviate problems stemming from increased demand include better use of existing infrastructure, all weather and night-time operations, additional runways within the perimeter of existing airports and new airports in the sea. Many of these measures necessarily include the design, simulation and validation and operational introduction of new concepts, processes and tools. In the Netherlands, Amsterdam Airport Schiphol, Air Traffic Control the Netherlands, the Netherlands Aviation authorities, and the Ministries of Traffic and Environmental Affairs have taken an early and active approach in formulating policies for the future of airports in the Netherlands. The objective is to co-operatively identify problems at national level to stimulate research and technology development and production of regulations and tools at both national and international levels, in such a way that results are easily useable for national airports at affordable costs. In Eurocontrol’s 1997 European Air Traffic Management System Operational Concept Document, the need for gate-to-gate and integrated planning by air transport stakeholders to fulfil capacity, safety, and cost requirements was clearly identified. The concept of a more co-operative planning concept based upon improved information management and the availability of more accurate and timely shared information drawn from a common information pool was already mentioned in this 1997 document. Changes in operational procedures were foreseen as well as air traffic controller support through more advanced technical systems such as an Advanced Surface Movement Guidance and Control System (A-SMGCS) to optimise the use of runway, taxiway, stand and apron resources. 57

The Road to the Virtual Enterprise - ICT in aerospace research and development

In the Eurocontrol strategy for 2000+ and the pertaining European Convergence and Implementation Plan, directions for change have been identified in more detail. Performance targets have been formulated for en-route and terminal area capacity planning as a first step, and projects for arrival and departure management have been formulated and begun. In addition, the importance of environmental constraints has been expressed more explicitly. The National Aerospace Laboratory NLR has been active in the area of information and communications systems for aerospace activities related to airports since the early 1980s. In this section, an overview is given of these developments. Four groups of systems can currently be distinguished: – Systems to support environmental monitoring, analysis and policy making. – Systems to address external safety concerns. – Advanced surface movement, guidance and control system components and architectures. – Integrated airport systems. A selection of three groups will be described, since these together depict the primary developments in the domain and in the ICT technologies to be used. Systems to support environmental monitoring, analysis and policy making

As early as 1982, under a contract from the Directorate-General of Civil Aviation (RLD), NLR developed the Flight track and Aircraft NOise MOnitoring System FANOMOS. This system has now grown to support several types of aircraft noise registration and analysis functions for a variety of stakeholders, including Netherlands Aviation Authorities, aviation regulatory authorities, complaint registration and analysis groups, and research and development institutes, in their search for better noise abatement procedures and systems. FANOMOS has the following main functions: – Flight track reconstruction – Monitoring violation of prescribed flight routes – Correlation between noise measurements and flights – Correlation between complaint data and flights – Calculation and monitoring of actual noise exposure – Statistical processing of flight data.

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Figure 25: Overview of noise and complaints for a flight departing from Schiphol airport

As an example, this FANOMOS picture (figure 25) shows an overview of information which can be made available by selecting items of interest from a menu built from available information in the FANOMOS database. In this case, the following information is displayed: – A map of the vicinity of Schiphol airport, including Schiphol’s runway topography and beacons (dotted circles, e.g. SPL for Schiphol) – An actual track of a selected flight (line in dark blue) – Flight information for that flight (in the legend) – Tolerances around desired flight route (lines in green) – Calculated noise for the flight. Noise levels > 65 dB(A) are shown (colour coded). – Noise contour lines for 65 and 80 dB(A) – Measured noise levels (correlated to the flights shown, displayed as a circle/ X symbol at the noise monitoring terminal location; the actual - maximum noise level is added) – Locations of submitted complaints correlated to the flight (black dots) In this way, relevant information can be presented for a variety of monitoring and analysis purposes. 59

The Road to the Virtual Enterprise - ICT in aerospace research and development

Operational systems have been installed at Air Traffic Control the Netherlands and at the Netherlands aviation regulatory authorities. These parties use FANOMOS for flight track and/or noise (load) monitoring for Amsterdam Airport Schiphol, Rotterdam Airport and Maastricht Aachen Airport. The latest version of the FANOMOS system has just undergone a major update, installing the newest technology, and has been extended to include advanced real-time interfacing with other operational air traffic data systems through the FANOMOS Input Processing system (FIP). In terms of information and communications technology, FANOMOS has evolved from a stand-alone system for one specific user group into a system being used by a variety of stakeholders. Advanced surface movement, guidance and control systems - A-SMGCS

A-SMGCS is the term used to describe an advanced modular system consisting of capabilities to support the safe, orderly, and expeditious movement of aircraft and vehicles on aerodromes under all circumstances with respect to traffic density, visibility conditions and complexity of aerodrome layout, taking into account the demanded capacity under various visibility conditions. Runway advisory, monitoring and reporting systems

Under contract to and in close co-operation with Air Traffic Control The Netherlands (Luchtverkeersleiding Nederland, LVNL), NLR has developed a decision support system for allocating runways for take-off and landing at Amsterdam Airport Schiphol, called BGAS. As Schiphol is located in a densely populated area, runways have to be chosen carefully in order to keep the noise exposure that air traffic imposes on the environment as low as possible. To this end, a preferential runway use system is used at Schiphol. If weather conditions and traffic density permit, those runways that cause the least noise exposure for the environment are used for take-off and landing. From runway use preference tables of all combinations of runways in use at Schiphol airport, the BGAS system determines the best runway combination listed in the order of the noise exposure that they impose on the environment. BGAS uses these tables in combination with actual weather data, traffic density information, runway availability data, and Instrument Landing System (ILS) data. BGAS is used by Air Traffic Control at Schiphol Approach and Schiphol Tower as an advisory system. To assist the air traffic controller, a compass rose representation that graphically presents the runway use preference tables is available (figure 26). It visualises the current wind situation and the limitations it imposes on starting and landing air traffic. The preferences for each of the 60

Airport operations as part of air transport

possible runway combinations are shown, given assigned wind limits and actual visibility limitations. Furthermore, a forecast function is available, by which the tool determines the preferred runway combination based on data provided by the user. This can be used to anticipate an expected upcoming situation. In addition to the advisory function, BGAS also has a registration function. If the Executive Controller chooses to use a runway combination that differs from the combination proposed by BGAS, the system asks for the motivation for the deviation. The combinations chosen and the motivations are registered for analysis by the BGCS tool.

Figure 26: Runway advisory system – Wind rose to depict preferential runway combinations

The BGCS tool determines what would have been the optimal runway use from an environmental point of view. This optimal use is determined from the same runway use preference tables that are used by BGAS, combined with all available weather information, traffic density, runway availability, and ILS data. This theoretically optimal runway use is then compared with the actual runway use as registered by the Schiphol Air Traffic Control System. Any deviations from the preferred runway use are analysed using the motivations for deviations that were registered with BGAS, and reported to ATC authorities and the Ministry of Transport and Communications in monthly reports. Since the end of 1998, BGCS has been fully operational at Schiphol Airport. 61

The Road to the Virtual Enterprise - ICT in aerospace research and development

Runway and taxiway safety support systems

As airports grow in size and in geometric complexity, tower controllers experience increasing problems to oversee operations through visual inspection from the tower. As capacity requirements increase, even under adverse weather conditions, new procedures become necessary, e.g. for reduced separation, land-behind and take-off after). These result in more intensive use of the airport infrastructure and in increased controller workload. Tools to alleviate workload and maintain safety at the highest possible levels include ground surveillance systems, advanced position detection means such as stop bars, and decision support tools such as runway and taxiway safety nets. From the current increase of simultaneous aircraft movements and an increasing use of intersecting runways and runway crossings, there is a large potential for conflicts and a need for tower controller decision support in runway surveillance and monitoring. In 1997, NLR started technology development work on a runway safety net tool to alert traffic controllers to runway incursions. A runway incursion is a situation where two or more aircraft or vehicles occupy one runway simultaneously and as such create a potentially dangerous situation. Note however, that we can also think of many situations where two aircraft/vehicles occupy the same runway simultaneously, but do not cause a conflicting situation, e.g. two taxiing aircraft on a closed runway or a departing aircraft lining up behind a landing one. If a runway incursion occurs (figure 27), immediate and decisive action of the controller is required to prevent a possible catastrophe. An automatic function that detects the threat of incursions and alerts to a potentially hazardous situation would improve the overall safety of the airport. This is especially the case under bad visibility conditions, when the controllers have difficulty seeing and identifying all traffic on the airport. A feasibility study of NLR, lead to the development of a proof of concept Runway Incursion Alert tool. The tool enables ground movement capacity to be optimised, while maintaining safety. The approach taken for RIA is based on mode-of-flight tracking, taking into account the observed states of aircraft and other moving vehicles. Primary information and communications technologies used for RIA are the combination of artificial intelligence, dynamic surveillance data processing, and man-machine interfacing technology. Concepts from expert systems were re62

Airport operations as part of air transport

Figure 27: A taxiing aircraft enters the safeguarding area of an arriving aircraft: a runway incursion

used to design an architecture that allows reasoning on the basis of dynamic surveillance data and operational knowledge to dynamically detect runway incursions. The conflict detection function can reason about the status of the aircraft and about active and inactive runways. Detected conflicts are judiciously displayed on an overlay of the airport lay out (figure 28). A separate window pops up, to contain additional conflict information. Tower controllers are given the capability to acknowledge conflicts. NLR’s RIA is designed to serve as an extra safety measure on the airport, working in the background. Another example of an airport safety net is the Taxiway Conflict Monitoring tool developed for Manchester airport. During low-visibility conditions, controllers may be unable to ensure separation of vehicles/aircraft on the airport movement area by visual means. Therefore, Manchester airport is relying on the use of stop bars. Current procedures result in drastic reduction of traffic throughput in low visibility conditions. Therefore, a novel approach was devised and implemented in the Taxiway Conflict Monitor (TCM). The TCM tools developed by NLR are designed to alert controllers to potential collisions between vehicles/aircraft on Manchester’s taxiways, even under adverse weather conditions. TCM monitors the position of aircraft on the ground as they move between terminal buildings and runways, and alerts controllers in the tower to potential problems. 63

The Road to the Virtual Enterprise - ICT in aerospace research and development

Figure 28 RIA conflict on a traffic situation display

The novel ICT approach used for TCM is the combination of a mathematical model of an airport’s interconnecting network of taxiways and knowledge about potential conflicts. The taxiway network topology (figure 29) is modelled as a non-planar graph where each node represents a rectangular area of taxiway called a segment. Each edge represents the node’s link to adjoining taxiway segments. The topology model needs to be established only once for each airport. As long as the airport’s taxiway layout infrastructure remains constant, the topology model will remain valid. Once the topology model is complete, the TCM monitors the positions and interaction of vehicles on the taxiways. Using the geometry of the topology segments, the connectivity of the graph, the dynamics of the vehicles, and the detailed definitions of conflicts, the TCM software compares vehicles’ current and predicted positions in its search for potential conflicts.

Figure 29: Manchester Taxiway model

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The TCM model was implemented in C++ and factory tested at NLR. Subsequently, NLR has integrated TCM into the A-SMGCS developed by the Dutch company Holland Institute of Traffic Technology (HITT) for Manchester Airport. Each potential conflict detected by TCM is forwarded to A-SMGCS’s user interface subsystem developed by HITT. The A-SMGCS has been installed at Manchester airport. Subsequently, TCM technology and tools have been re-used by HITT to provide taxiway support tools for other airports. Management of Traffic at European Airports - MANTEA

The objective of the MANTEA(Management of Traffic at European Airports) project in the context of the Fourth Framework Telematics Applications Programme of the European Commission., was to develop decision support tools for improvement of surface traffic management in European airports. The tools developed in the project provide support to ground and tower controllers through advancements in the fields of surveillance, planning/routing, monitoring/control, and human machine interfaces. The tools help controllers to carry out tactical decisions in the processes of airport surface traffic planning and monitoring under nominal and critical situations (bad weather conditions, strike, etc.). The tools have been evaluated at the MANTEA validation sites of Paris Orly and Rome Fiumicino. The main MANTEA requirements for traffic management at airports were to achieve maximum capacity while maintaining safety at the highest possible level. Planning should not be done independently, but in co-ordination and co-operation between several airport planners (departure planning, arrival planning, surface movement planning, conformance monitoring and guidance). These functions were not only to support airport controllers, but pilots and drivers of other moving vehicles as well. In addition, integration with air traffic en route needed to be achieved. Constraints played an important role in describing this complicated set of co-operative and coordinating tasks. Apart from top-level requirements gathering and domain modelling, NLR’s contribution to the MANTEA project was focused on a planning function to support airport tower controllers in the establishment of runway departure plans and corresponding Standard Instrument Departures (SIDs).

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For the MANTEA Airport Departure Sequencer (MADS), an innovative co-operative planning process and planning architecture was selected. It has been designed to be integrated in an environment of co-operating air traffic controllers with accompanying tools, where several controllers act on one plan for each aircraft. MADS supports this innovative process for departure planning (figure 30), starting at the runway, usually the scarcer resource, and then supporting the generation of a taxi plan by the surface movement planner backwards through time. The process ends with the establishment of a start-up time by a push-back or pre-flight planner. In addition to the first process innovation of backward planning, a second innovation is that the MADS tool is designed to handle mixed mode operations in co-ordination with an arrival planning tool. This will enable future developments in the integration of work processes of airport planning (departures) and en-route air traffic management (arrivals). A third innovation lies in the application of advanced information processing for decision support systems. Following the modelling of departure management in terms of optimisation under a large number of potentially conflicting constraints, solutions have been defined by using constraint satisfaction techniques from the fields of artificial intelligence and operations research. Satisfactory high-performance solutions were found by using heuristics based on general problem solving methods available in artificial intelligence in combination with heuristics based on domain-dependent runway departure planning methods used by controllers. A major advantage of the approach taken is that all safety regulations are checked automatically, not only after creation of the departure sequence, but also during planning when optimising runway usage. 66

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MADS and other planning tools were developed as components in a CORBAbased object-oriented software architecture. Objects were implemented in C++ and communication between objects on different platforms was implemented through object request brokers as part of a CORBA commercial implementation package. In MANTEA, MADS has been integrated in a tower control simulation environment and successfully evaluated by tower controllers at Paris Orly and Rome Fiumicino airports Real-time man-in-the-loop simulation of A-SMGCS - SAMS

Sponsored by the European Commission, a European consortium has developed and evaluated a real-time, man in the loop simulator of A-SMGCS (figure 31) (SAMS), capable of testing and demonstrating new support tools and new procedures in all weather conditions. A pilot working environment (LATCH, B747 cockpit), a controller working environment and an outside view projection system of a Control Tower (ATS) were connected to the core A-SMGCS simulator. Both the flight and tower simulator feature high fidelity visuals immersing the pilots and controllers in a realistic working environment. The internationally networked SAMS environment offered a highly realistic substitution of outside views and of controller working environment at all sites.

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Figure 31: The SAMS Simulators for testing of distributed A-SMGCS concepts 67

The Road to the Virtual Enterprise - ICT in aerospace research and development

The three simulators were located at three geographically distributed sites. The LATCH flight simulator was located at DERA in Bedford (UK), the tower simulator ATS was located at DLR in Braunschweig (D), and the A-SMGCS simulator was based at NLR in Amsterdam (NL). While LATCH and ATS are existing simulators, construction of the A-SMGCS simulator was one of the activities in the project. A distributed real-time architecture was set up using object communications principles based on CORBA and DIS. Subsequently, the A-SMGCS simulation environment was integrated with the flight simulator and tower simulator using high-speed networking and the real-time Distributed Interactive Simulation (DIS) protocol.

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Figure 32: The SAMS A-SMGCS distributed real-time simulation environment

In this way, an A-SMGCS environment containing airport traffic management information and procedure components was integrated with pilot and tower simulation capabilities simulating a highly realistic working environment for controllers. The integrated SAMS distributed real-time simulation environment contained unprecedented capabilities to simulate in real time a distributed flight planning process with realistic operations simulation feedback, using components spread over Europe. Simulation experiments were managed using NLR’s Simultaan Federation Manager. The SAMS platform has been successfully used to investigate new operational airport traffic handling procedures, to demonstrate A-SMGCS software and hardware, to help define performance requirements for future A-SMGCSs, and last but not least help define performance requirements for future distributed air traffic service support systems. 68

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Integrated support systems

As separate systems have matured from technical and operational feasibility to operational support systems, stakeholder requirements shift towards integration of existing and future systems, both for policy making and for operations support. The objective of the Airport Scenario Analysis Package (ASAP), figure 33, is the provision of an information system that supports integrated scenario analyses and policy making for airport-related issues. The system is being designed to behave like a single environment towards a variety of users in different organisations, by seamlessly integrating distributed application components over a network, and providing access via a uniform graphical user interface. As a first step, a distributed computing architecture has been defined in which applications and data are provided in a form that can be accessed by users via a network, without regard to the physical locations of the users, components, and data. Two primary types of users can currently be distinguished: 1. Users that use available collections of data and applications 2. Users that extend available data sets and applications The first type of user is supported by an environment that presents the tools and the information needed for the task(s) in a uniform way, via a graphical user interface. The user interface hides the possibly heterogeneous character of tools and information; ASAP ensures a single-environment look and feel for this user. Examples of tools to be provided to these users include tools for using impact calculations (e.g. noise, third party risk, emissions), tools for scenario definition and analysis, data generators (traffic, routes, aircraft), result analysis tools (traffic build-up, noise build-up) and trend processing tools.

Figure 33: Overview of ASAP 69

The Road to the Virtual Enterprise - ICT in aerospace research and development

The second type of user views the ASAP system as a rapid application development environment. ASAP provides these users with tools to gather and manage requirements, with tools to model business processes, and with tools to develop, integrate, test, field and maintain applications in a variety of configurations. The underlying modelling, analysis and development framework is based on object-oriented approach in which use cases and requirements drive the design, and advanced tools and services provide much of the code generation and communications. The software production, configuration and maintenance tools (see also section 5) have been set up in such a way that hardware and operating system dependencies can be kept to a minimum, thereby enabling easy changes in development environment for this type of user, as well as easy transfer of the system under development to an end user’s target environment. This independence of computing infrastructure is essential for long-lived applications found in airport support development and operational systems; hardware and software technologies have a shorter life cycle than the airport support analysis package and its components (figure 34). For the first ASAP applications, relatively simple graphical user interfaces have been developed. For future more complicated applications, workflows presented via the user interface may guide application users through their processes. These workflows will be based on the business and task models established in the first phases of the modelling and development process. The underlying software components carrying out computing processes on pertaining data will be coupled using integrated tool chaining and data management (see also section 5). In this way, users can focus on their essential tasks, and need not to worry about the correct ordering of steps and combination of underlying tools and data. SPINEware ASAP – User shell (Working environment)

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Figure 34: ASAP developer view 70

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Air Traffic Management Air Traffic Control Harmonisation and Integration

Air transport is expected to grow further at a rate of no less than 5 per cent annually, and is expected to nearly double by 2015 when compared to 1998 levels. Major airports are struggling to keep up with the demand for more capacity. The challenges facing European air transport are to simultaneously generate extra capacity to meet the demand for more flights, to increase safety levels, to reduce costs, to provide excellent quality of service including passenger comfort, and to comply with growing environmental requirements and constraints1 . This requires a new approach to the way in which air transport services are provided, characterised by increasing communications, and both substantial co-operation as well as negotiations between stakeholders. As an example, Eurocontrol states that a new approach is required for air traffic management services. This approach is characterised by the vision that air traffic management should be seen as part of a complex network of individual systems, including those of the aircraft operators and the airports, which all interconnect and pass data to each other, in order to operate as if it was a Virtual Enterprise. Contribution to activities in the ATM area with a large ICT content are found in surveillance and in the work performed in multi-site simulations for ATM research. Surveillance

An important element of European ATM harmonisation and integration is to achieve surveillance integration by combining all types of surveillance data from different sensors into a seamless and accurate air situation representation. A key element in surveillance technology is available now - ARTAS - the ATM suRveillance Tracker And Server providing uniform surveillance data for the current and future European air traffic management system. The ARTAS system was developed, to address all perceived Radar Data Processing problems, in particular for the overall System in a given area to operate from a User’s perspective, “as if it were a single unit” ensuring a fully seamless operation. Therefore from the User perspective ARTAS presents itself as one single system, operating at a regional level.

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The Road to the Virtual Enterprise - ICT in aerospace research and development

NLR has contributed in the research and development of new multi-radar tracking technology. The joint effort of NLR’s ATM and ICT divisions led to participation in an industrial consortium for the development of ARTAS in which NLR specifically was responsible for the multi-radar tracking component of ARTAS. The capabilities of NLR in the surveillance area could be directed to further exploiting the tracking technology for military purposes in the Military ARTAS (MARTAS) project (see below) and for the purpose of surveillance in Advanced Surface Movement Ground Control Systems. The ARTAS Tracker

The ATC Radar Tracker And Server, ARTAS in short, is an advanced radar data processing system that is developed for Eurocontrol in the context of the European Air-Traffic Control Harmonisation and Implementation Programme (EATCHIP). Since mid 1993, NLR has been working on the ARTAS system, in particular on the ARTAS Tracker, as a sub-contractor of Thomson-AIRSYS. Since April 1998, ARTAS is in operational use, supplying track data to the Schiphol Amsterdam Advanced ATC (AAA)-system. The ARTAS Tracker processes the data of up to 30 Primary (PR), Secondary (SSR) and Mono-pulse (M-SSR) radars in an area of 1024 nautical mile (NM) by 1024 nautical mile and provides a clean air-picture to e.g. air-traffic controllers.

Figure 35: ARTAS in the ATM environment 72

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ARTAS units are connected to a wide-area network (WAN) (figure 34), connecting the radar sensors, ATC centres, Flightplan Data Processing Systems (FDPS). Through the WAN, ARTAS receives the data from the radar sensors, data from adjacent ARTAS units and data from FDPS units. Furthermore, all track data, generated by the ARTAS unit, are distributed via this WAN. ARTAS is designed as a track data server. Track data users can subscribe as a client with the ARTAS unit to obtain a certain track data service. Each client individually can specify the content of the track data and the frequency, with which the track data needs to be sent. Normal clients are ATC centres (for the controller working positions), FDPS units and air-traffic management units, like the Central Flow Management Unit in Brussels. Special clients are the adjacent ARTAS units. Adjacent ARTAS units exchange track data for two main reasons, i.e. to guarantee a smooth transition of tracks from one ARTAS domain of interest to another, adjacent, ARTAS domain of interest and contingency. In case of contingency, that is the failure of one unit, adjacent ARTAS units can take over the tracking and the track data distribution of the failing unit. The ARTAS tracker uses advanced probabilistic filtering techniques, like the Interacting Multiple-Model (IMM) filter, Probabilistic Data Association (PDA), Joint-Probabilistic Data Association (JPDA) and Multiple-Hypothesis Tracking (MHT) to obtain maximum tracking accuracy, while still being able to follow expedite manoeuvres of military aircraft without track loss. Other features of the ARTAS tracker are on-line systematic error estimation for all radars, false plot classification and track-type classification. Systematic radar errors, like e.g. range bias, range gain bias, azimuth bias and time-stamping bias, are assessed continuously. This is a pre-requisite for optimum multi-radar state vector estimation in a continuously changing radar environment.

tracks

radar reports tracks

Track Continuation

radar reports

new tracks

radar environment

tracks

Multi-Radar Environment Assessment D348-03a

Track Initiation

Track Dressing Management

Figure 36: ARTAS Internal Structure

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The ARTAS Tracker consists of four main modules: Track Continuation, Track Initiation, Multi-Radar Environment Assessment and Track Dressing Management (Figure 36). The Tracker receives the radar (position) reports per radar in pie-shaped sectors; 32 sectors of 11.25° wide and 75 NM to 300 NM long per radar revolution. As soon as a sector with radar reports is received, tracks within that area are updated with the new information. Radar reports that cannot be associated to any track are either the start of a new track or false reports. The distinction between these two cases is made by the Track Initiation. The Multi-Radar Environment Assessment estimates the radar systematic errors, the radar accuracy and probability of detection and keeps maps of the false reports to aid the Track Continuation and Track Initiation. The Track Dressing Management, classifies tracks as being aircraft or non-aircraft (in the latter case, the track consists of false reports). It corrects track swaps in the unlikely event that, when tracks have been in resolution, i.e. they could not be resolved uniquely by the radar, the track identities have been swapped. It also maintains track identity continuity when the track was terminated and re-initiated due to radar detection problems. Track identity continuity is important for air-traffic controllers, but also for further automated processing of the track data. The ARTAS2 Tracker

The ARTAS2 (ATM suRveillance Tracker And Server) system is an evolution of the ARTAS system, which is tailored for the future CNS/ATM environment. The ARTAS2 Tracker integrates aircraft-derived data, that is down-linked via Automatic Dependent Surveillance (ADS)- and/or Mode-S sub-networks, with classical radar data. Aircraft-derived data items of particular interest are the aircraft technical address that uniquely identifies each aircraft, the (ground-referenced) state vector from the on-board flight management computer and intention data, such as next waypoint information, also from the on-board flight management computer. Furthermore, the Tracker takes into account the ModeS enhanced altitude resolution of 25 feet. A feasibility study is in progress that demonstrates the potential of new algorithms to integrate this aircraft-derived information at report-level within the tracking filters. This is done in two ways: through extensive simulations and by implementation of a prototype tracker, based on the existing ARTAS tracker Tracker Testing and Evaluation

Apart from contributing to tracking, NLR has also contributed in Radar- and tracker evaluation software. Results of NLR’s contribution are found in components of the Surveillance Analysis Support System for ATC Centre (SASS-C), with the goal to provide to ECAC states standardised ATC Centre-based Sur74

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veillance analysis methods and tools. In order to facilitate the tracker development, testing and evaluation, the ICT division has developed the working environment TRADEF, TRAcker DEvelopment Facility. TRADEF contains tools for the simulation of air traffic and the radar environment, tools for replay of simulated radar data and recorded live radar data and recording of the generated track data, various tools for visualisation of radar data and track data and statistical analysis tools. TRADEF also comprises the Eurocontrol SASS-C software for radar data analysis. Scenarios (figure 37) are generated through the Simulator for Multi-Radar Analysis for Realistic Traffic (SMART) and stored on disk. They are replayed in real-time and the output track data is captured and recorded on disk for analyses. The analysis starts with chaining the radar reports of each trajectory. These chains are also correlated with the track data, resulting in track-to-chain associations. All further statistical analyses make use of these associations..

Figure 37: SMART simulated radar scenario on a realistic en-route airspace structure

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MARTAS-project

In co-operation with the Dutch industry HITT (Holland Institute of Traffic Technology), NLR has build an tracker Evaluation System for military surveillance, the Military ARTAS (MARTAS) project. This system is placed in the Surveillance Laboratory of NC3A The Hague in order to perform evaluations and adaptations on behalf of the Royal Netherlands Air Force. The goal of this project is to reach tracking performance for both military and civil traffic similar to (equal or better than) the specification in the ACCS pre-selection. Again, NLR is responsible for the tracking part in this project. The system blockdiagram below (figure 38) shows the basic layout of the MARTAS Evaluation System installed for evaluation of: – the Basic ARTAS tracking algorithms, – the windows OSF-look-and -feel based air traffic display and – the ASTERIX data formats for radar data exchange. The NC3A Local Area Network (or any comparable radar network) serves as backbone for delivering plot data from several military and civil (radar) sensors and communicating tracked data from MARTAS to other evaluation systems using the TCP/IP transmission protocol. NC3A LAN Tracks

Plots

Radar Front End

Plots

TRACKER

Tracks

Plots

Tracks

TRADIS-30 Display

Tracks COMMS

Figure 38: MARTAS Evaluation System overview

MARTAS comprises the following main components: – Radar Front End The HITT supplied Radar Front End (RFE) receives plot data from the NC3A LAN and translates this data into a format suitable for handling by the basic ARTAS tracker and sends this plot data via the internal LAN the ARTAS tracker. Before transfer of the plots the RFE performs consistency checks on the incoming data, allocates the incoming plot data to sectors of 11°15’ and makes some basic corrections for systematic errors. The RFE also sends tracks back in ASTERIX category 30 format to NC3A LAN including a dedicated header for processing by other evaluation equipment. The RFE is a DEC-Alpha based computer platform with UNIX as operating system; the application is written in C++. 76

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– Basic ARTAS The NLR supplied basic ARTAS performs the actual multi-radar tracking on the plot and track data received from the RFE. During the tracking statistical data can be viewed via the display connected to this system. The Basic ARTAS receives radar plots from the RFE and broadcasts tracks in ASTERIX Category 30 to the RFE and the TRADIS-30. The Basic ARTAS runs on a DEC-Alpha based computer platform with UNIX as operating system; the application is written in Ada – TRADIS-30 Display The HITT supplied TRADIS-30 presents tracks as received in ASTERIX Category 30 in a multi-window OSF- Motif Look-and-Feel environment. The Human Machine Interface is based on the ODID IV guidelines from Eurocontrol . The TRADIS-30 runs on a DEC-Alpha based computer platform with UNIX as operating system; the application is written in C++. The display monitor is 21” colour monitor with a resolution 1600*1200. For control of the presentation a mouse and keyboard are connected. NC3A, with the help of NLR, has tested MARTAS using simulated scenarios, containing specific military manoeuvres. These tests of MARTAS have been performed before and after making modification to the MARTAS tracker. This enabled NLR to clearly show where the tracker algorithms (initially being developed for mainly tracking civil aircraft) could be improved to follow military aircraft as well. It also enabled NLR to clearly show the benefits of the adaptations after the re-testing had been performed. The results of the test of NC3A, the NLR adaptations to the MARTAS tracker and the NLR analysis of the results have been presented (together with RNLAF, NC3A and HITT) to representatives of the military and civil aviation authorities (including LVNL, RNLAF and Eurocontrol). In the mean time, NLR has already started to prepare for the third and last phase of the MARTAS project; validation of the adapted MARTAS tracker against the Eurocontrol standards (as used for the acceptance testing of the ARTAS tracker). A validation test environment within TRADEF has been created, using SPINEware v3.0, that will automate the running of MARTAS validation test.

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Multi-site simulations in ATM NLR Air Traffic Control research simulator

NLR has developed a real-time Air Traffic Control Research Simulator (NARSIM). With NARSIM, the Air Traffic Control (ATC) process can be simulated having both the air traffic controller and the pilot in the loop. NARSIM (figure 39) serves to support research in the field of Air Traffic Management (ATM). In the past several years, NARSIM has been used in research programmes for a variety of customers.

Figure 39: Detailed view of the Netherlands airspace structure

Based on GEAR simulator middleware, NARSIM is a flexible ATC simulator providing for easy simulation configuration and external software integration. Interfaces to connect NARSIM to flight simulators, to ATC simulators and to the NLR research aircraft are available.

To investigate new ATM concepts, NARSIM features voice and data links with both research aircraft and research flight simulators. NARSIM can accommodate investigations on several ATM topics: – the Human Machine Interface (HMI); – development and validation of ATM concepts and procedures; – development and validation of advanced air traffic controller assistance tools; – support of qualitative safety assessments. In NARSIM, the functional elements of existing or future ATM systems are incorporated as separate functional modules including: – air traffic simulation; – multi-sector simulation; – radar simulation; – meteo simulation; – arrival manager; – ATCo interface; – datalink simulation.

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Figure 40: GEAR distributed monitoring facility

These modules are tied together by NARSIMS’s advanced GEAR simulator middleware (see chapter 6). On top of this middleware, a distributed debugging tool, the supervisor, has been built. The supervisor allows events and data to be traced throughout the simulator, monitors the internal and external states and offers the possibility to start and stop the modules dynamically (figure 40). TRS: the NLR Tower Research Simulator

NLR operates a real-time Tower Research Simulator (TRS) for advanced research of SMGCS (Surface Movement Guidance and Control Systems) under reduced visibility conditions. The TRS is capable of simulating Air Traffic Control and Apron Control activities at airports under nearly realistic operational conditions. The NLR Tower Research Simulator (TRS) is well suited for applications where the human aspect plays an essential role, such as the following: – Acceptance studies of Human Machine Interfaces for advanced industrial SMGCS equipment, reducing implementation risk; – Validation of Human Machine Interfaces for controller working position design; – Studies of airport capacity, safety and efficiency under dense traffic and zero/low visibility conditions; – Studies of airport contingency in emergency situations; – Testing and optimisation of future tower procedures and airport infrastructures; – Investigation of data link versus radio telephony trade-offs; – Recurrency training and legislation of controller procedures for new airport environments (Runway Incursion Alert). 79

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A modular design has been implemented for both the hardware and the software of the TRS. The software architecture is based on distributed client/server applications in combination with the GEAR simulator middleware (see chapter 6), a Unix operating system and an extended C/C++ software library. Currently, NLR’s TRS consists of three controller working positions, for the Tower, Ground and Start Up controllers, respectively. Each position is equipped with three touch input displays, one for radar, one for flight plan and one for auxiliary data (stop bar panel, lighting panel, etc.). Two pseudo-pilot positions, each with two dual-head displays, are applied for controlling the aircraft. An experiment leader console and a high performance computing and data server complement the basic configuration. The TRS is connected to NLR’s Information and Communication Infrastructure. Links have been realised with the Research Flight Simulator (RFS), the National Simulation Facility (NSF), the NLR Air Traffic Research Simulator (NARSIM) and the Cessna Citation II and Fairchild Metro II research aircraft. In conjunction with other simulation tools such as the Total Airspace and Airport Modeller TAAM®, a consolidated toolbox for cost-effective airport research has been realised, ranging from parametric modelling and fast-time simulation to pre-operational trials supported by real-time simulation. An ISDN-DIS/HLA networking environment facilitates large-scale multi-site simulations for ongoing international projects. The TRS will be extended with an outside visual system supporting a 135° by 40° field of view in 2001. High-performance LCD projectors will enhance visual realism for small targets and haze/fog situations. This configuration will be ideally suited for research on transitions between radar, enhanced vision systems with video and infrared, and real outside vision (figure 41).

Figure 41: TRS visual system at NLR, operational from mid 2001 80

The road to go In the previous sections the Virtual Enterprise concept is introduced and the effort of ICT on the road to the Virtual Enterprise is presented in various representations in a number of application domains in aerospace. Manifestations as working environments within a company are in common use. With to day’s technology, these working environments enable crossing of organisational boundaries, both within an organisation and among organisations. Standards for information exchange are applied successfully in various aerospace domains, both civil and military. Considerable progress has been achieved, but there are still a large number of open issues requiring further developments. In spite of the fact that most of the initial projects are focused on the development of Virtual Enterprise infrastructures, various aspects remain without proper solution. The use of standards for technical information exchange, is common practice, but there are many other types of information, that are required to be exchanged within Virtual Enterprises, but are not yet properly addressed by these standards. That holds for, for example, quality/certificate-related information, monitoring information for distributed business process management, electronic catalogues information, contract terms and regulations information. Much more work is necessary to support the Virtual Enterprise creation and its configuration / re-configuration phase. In terms of the Virtual Enterprise: agreement negotiation and decision making support tools, distributed business process planning and scheduling, configuration of co-ordination mechanisms based on the contractual clauses established among companies. Regarding the Virtual Enterprise dissolution phase, the subject is almost not touched by current work and many support functionality need to be developed. The enterprise applications are both the main sources and consumers of the information that is interchanged among the Virtual Enterprise partners. Therefore, on one hand the interface mechanisms between these systems and the Virtual Enterprise infrastructure must improve, and on the other hand these applications themselves need to be better adjusted to support the Virtual Enterprise activities. Although safe communications and independence of the channels is one of the most active development areas in electronic business, there is a need for simplification and standardisation of mechanisms, making them available as basic services of the underlying network infrastructure.

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An important aspect in the area of infrastructures is “geographical independence”. As a Virtual Enterprise may involve members in different geographical regions, even in different continents, there are obvious advantages in aiming at wider standardisation of the basic levels of the infrastructure. To achieve this goal, there is a need to identify the basic level of functions that are needed to become common practice, which also motivates a more global international cooperation. Solutions developed for one particular region are not necessarily easily adaptable to other regions due to the many technological, cultural and business practice differences. It is also natural that real business practices and processes will change as a result of their first experiences in Virtual Enterprises. As a result, new requirements will emerge and new supporting functions must be developed. Not only new tools and applications will be required, but also all the traditional enterprise applications must be “re-visited” in order to take into account the networked cooperative environments. The deployment of an appropriate Common ICT infrastructure, which will be shared on an (virtual) enterprise-wide scale, will enable new collaborative applications between multi-supplier, multidisciplinary teams and will facilitate the implementation of new business and new methods of work.

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Abbreviations and Acronyms ACCS ADS ANS AOCS AOPTS API ARTAS ASAP A-SMGCS ATC ATCCIS ATM ATO

Air Command and Control System Automatic Dependent Surveillance Astronomical Netherlands Satellite Air Operations Control Station Air Operations Planning and Tasking System Application Programme Interface ATM suRveillance Tracker And Server Airport Scenario Analysis Package Advanced Surface Movement Guidance and Control System Air-Traffic Control Army Tactical Command and Control Information System Air-Traffic Management Air Task Order

C4ISR

CAE CAOC CFD CMM CNS CORBA COTS

Command and Control, Communications, Computer Intelligence, Surveillance and Reconnaissance Computer Aided Control Engineering CAD Computer Aided Design Computer Aided Engineering Combined Air Operations Centers Computational Fluid Dynamics Capability Maturity Model Communication, Navigation, Surveillance Common Object Request Broker Architecture Commercial Off the Shelf

DBMS DIS DMZ DOD

Data Base Management System Distributed Interactive Simulation DeMilitarised Zone Department of Defence (USA)

CACE

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EATCHIP

European Air-Traffic Control Harmonisation and Implementation Programme ECAC European Civil Aviation Conference ENHANCE Enhanced Aeronautical Concurrent Engineering EPC Experimenter Processing Center ERA European Robotic Arm EUROSIM European Real-Time Operations Simulator ERP Electronic Resource Planning ESTEC European Space Technology Centre

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FANOMOS FDPS FEDEP FIP FTP

Flight track and Aircraft Noise Monitoring System Flightplan Data Processing System Federation Development and Execution Process Fanomos Input Processing system File Transfer Protocol

GUI

Graphical User Interface

HCS HITT HLA HMI HPC HPCN

HPCN Center for flow Simulation Holland Institute of Traffic Technology High-Level Architecture Human Machine Interface High Performance Computing High Performance Computing and NetworkingICAOC Interim Combined Air Operations Centres

ICC ICI ICT ILS IMM ISEnS ISMuS ISNaS ISTAR IT

Integrated Command and Control Information and Communication Infrastructure Information and Communication Technology Instrument Landing System Interacting Multiple-Model Information System for Engineering of Software Information System for the development of Multibody Systems Information System for Navies-Stokes Solvers Information System for SafeTy and Risk analysis Information Technology

JPDA JWID

Joint-Probabilistic Data Association Joint Warrior Interoperability Demonstration

Abbreviations and Acronyms

LCD LVNL

Liquid Crystal Display Luchtverkeersleiding Nederland

MADS MANTEA Airport Departure Sequencer MANTEA Management of Traffic at European Airports MARTAS Military ARTAS MDO Multidisciplinary Design Optimization MHT Multiple-Hypothesis Tracking MoD Dutch Ministry of Defence MOSAIC Model-Oriented Software Automatic Interface Converter MPTE Mission Preparation and Training Equipment M-SSR Monopulse MTRAQ Multi Radar Tracker Quality Analysis MURATREC Multi-Radar Trajectory Reconstruction NARSIM NATO NC3A NICE NIETI NIVR NLR NM

NLR Air Traffic Control Research Simulator North Atlantic Treaty Organisation NATO Consultation, Command and Control Agency Netherlands Initiative in Computational Fluid Dynamics (CFD) for Engineering Nato C3 Interoperability Environment Testing Infrastructure Nederlands Instituut voor Vliegtuigontwikkeling en Ruimtevaart Nationaal Lucht en Ruimtevaartlaboratorium Nautical Mile

OIL OMIS OS

Object Interface Layer Operations Management Information System Operation System

PC PDA PDM PR

Personal Computer Probabilistic Data Association Product Data Management Primary surveillance Radar

R&D RFE RFS RIA RNLAF

Research and Development Radar Front End Research Flight Simulator Runway Incursion Alert tool Royal Netherlands Airforce

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SAMS Simulator of A-SMGCS SASS-C Surveillance Analysis Support System for ATC Centre SDE Simulator Development Environment SMART Simulator for Multi-Radar Analysis for Realistic Traffic SMARTFEDScenario Manager for Real-Time Federation Directing SMGCS Surface Movement Guidance and Control Systems SPINE Software Platform for ISNaS in a Network Environment SPL Schiphol SQL Standard Query Language SSR Secondary Surveillance Radar STEP Standard for the Exchange of Product Model Data

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TAA TAAM® TCM TCP/IP TRADEF TRADIS TRAQUME TRS

Tracker Accurancy Analysis Total Airspace and Airport Modeller Taxiway Conflict Monitor Transmission Control Protocol/Internet Protocol TRAcker DEVelopment Facility Traffic Display Tracker Quality Measurement Tower Research Simulator

WAN WWW

Wide-Area Network World Wide Web

National Aerospace Laboratory NLR Anthony Fokkerweg 2, 1059 CM Amsterdam The Netherlands April 2001 ISBN 90-806343-1-x