TRANSMIT project is a Marie Curie Initial Training Network (ITN), funded under the EU FP7 framework . The programme vision is to act as the enabler of the IPDM network  which will deliver the state-of-the-art to protect the range of essential systems vulnerable to ionospheric threats.
TRANSMIT’s primary mission is to provide Europe with the next generation of researchers, equipping them with skills, through a multi-disciplinary, inter-sectorial, comprehensive, coordinated, industry-led training programme. The training offered, should enable the new researchers to understand in depth, the threats that ionosphere poses on modern technological systems, and more importantly on GNSS Precise Point Positioning (PPP) value chain , and respond to the needs of various stakeholders for robust counter-measures to deal with these threats. The secondary mission of TRANSMIT project is to develop real-time integrated state-of-the-art tools to mitigate the ionospheric threats, and make these tool available and accessible to the various stakeholders, via the “
In this chapter we concentrate on the definition of the “
DM is typically organized into ten basic components or functions, each consisting of a family of activities that belong to one of four groups ; planning activities (P) that set strategic and tactical course for other DM activities, development activities (D), undertaken within the system development lifecycle, creating data deliverables through analysis, design, building, testing, preparation and deployment, control activities (C) or supervisory activities performed on an on-going basis and, finally, operational activities (O) to include service and support activities performed on an on-going basis.
At the heart of any data related activity is Data Governance (DG). DG is the core function of DM that guides how all other functions are performed and it can be defined as “
In sections 2, 3, 4 the TRANSMIT Business and IT/S strategies are described since are required inputs for the definition of data strategy. Finally, in section 5 we formulate the TRANSMIT data strategy, and provide in the closing section the state of art regarding the implementation status of this strategy.
2. Business strategy overview
The TRANSMIT business strategy presented in this section focuses on four themes which are the identification of the relevant business area and process, assessment of the business problem, a solution strategy and expected competitive advantage from the TRANSIT project, that can be further exploited by the future IPDM system, based on that strategy. The selection of appropriate business services (see section III) to support the given business problem is determined by the chosen business strategy and also drive the DG planning activities by providing the required data/information needs for which the data strategy is being developed.
The TRANSMIT project focuses on GNSS precise positioning business area. From a business perspective, PPP is a business process that outputs positions with high accuracy anywhere on the globe using a single GNSS receiver. To achieve that, a GNSS receiver on PPP mode relies on typical GNSS observables as well as input data products, i.e. precise orbits and clocks, provided by external entities, such as the International GNSS Service (IGS) . More detailed information about PPP, can be found in  and .
In both single-(L1) and dual-frequency (L1+L2) PPP modes, and after the permanent removal of Service Availability (SA), the ionosphere has become the largest source of error that can potentially degrade the quality of the estimated user position. More specifically, and as described in , ionospheric scintillation, which is produced by ionospheric irregularities, affects GNSS signals in two ways, broadly classified as refraction and diffraction. A more thorough treatment of the effects of ionosphere on wideband GNSS signals can be found in .
At the application level, the refractive effect manifests as a group delay and phase advancement of the GNSS signal. A slower group delay velocity produces ranging errors while a faster phase velocity causes unexpected phase shifts. If the phase shifts are rapid enough, they can challenge the tracking loops in the receivers. In dual-frequency mode, the linear combination of observations and the formation of the so-called ionospheric-free observable, eliminates the biggest part, almost 99%, of this kind of ranging-error, however for very precise positioning, the remaining, higher-order terms need to be considered and compensated . For the case of a single-frequency PPP mode, this ionospheric delay is typically corrected using available ionospheric models such as the Klobuchar, IRI and NeQuick ones , .
As far as the diffraction effect of the ionosphere is concerned, the situation is more complicated and influences the GNSS service availability. Compensation of the effect cannot be achieved, but only mitigation is possible. It should be stressed that in situations of severe diffraction, a total loss of signal at the receiver site can be caused, which make any mitigation technique useless. In these cases prompt warning of forthcoming strong signal scintillations, can provide valuable time to businesses to alter their service delivery strategy, e.g. switching from GNSS to other means of providing precise positioning.
There are different ways that TRANSMIT project could support GNSS service providers in dealing with the ionosphere as a potential risk. Here we refer to the lesson learned by collaborating with FUGRO Intersite B.V. , one of the biggest GNSS service providers which carries activities worldwide, focused on four key areas, namely Geotechnical, Survey, Subsea Services and Geoscience, and targeting markets such as the oil and gas, building and infrastructure, mining, renewable energy and other public and private sectors.
One of its main requirements towards the TRANMSIT project can be phrased as “
To ensure the sustainability of the TRANSMIT endeavor, a clear differentiation of the TRANSMIT approach with respect to competitors have to be foreseen. In Figure 2, the
3. IS strategy
In broad terms, information systems (IS) strategy defines what kind of system is necessary to cover the business needs for the foreseeable future. It is based on proper analysis of the business, its environment and the general business strategy . In this section we focus and outline some key features of the required TRANSMIT IS, and we outline the application portfolio  which contains the currently developing business services.
TRANSMIT IS will be realised as an “
As far as the TRANSMIT IS is concerned the functionality has been split into 4 layers following the multi-tier architectural paradigm. The data and presentation layers consist of one tier each while the business layer consists of various tiers, deployed on the premises of the Institutions partners of the TRANSMIT project .
The TRANSMIT IS will act as the demonstrator of the capabilities (business services) developed from the research base of the programme. The “prototype” term implies that the system will be intentionally incomplete, i.e. will capture only the essential features of IPDM , and is to be modified, supplemented, or supplanted  in order to realize the desired future state. For its development various methodologies exist , however the one that represents more adequately the philosophy of TRANSMIT project, is the evolutionary  presentation  prototyping. This iterative methodology allows flexibility in the software development process so that it can adapt to changing requirements, and also convince end-users of the feasibility of the system, as shown schematically in Figure 3 below. TRANSMIT IS prototype is based on a consortium that brings together some of the biggest GNSS Rx manufactures and precise positioning service providers, to act as the end-users (e.g. Fugro) as well as leading research institutes and universities around the Europe to lead the system development and provide the different services as well as the initial system and user requirements.
For what concerns the application portfolio, i.e. business services, hereafter few examples are given as current services developed as part of the TRANSMIT IS with potential value in PPP business area for the end customers (e.g. Fugro). The first service aims to deliver improved estimation, after interference cleansing, and prediction of amplitude scintillation parameter, S4. The second concentrates on providing improved ionospheric delay estimation for different geomagnetic conditions. These services generally needs support and contributions from the TRANSMIT partners in terms of data (e.g. measurements from various ground-based and space-borne instruments, such as GNSS, ionosondes, and radio occultation) and modeling (e.g. advanced 3D tomographic techniques, forecasting, etc.
4. IT strategy overview
The IT strategy for TRANSMIT is split into two sections as shown in Figure 1: internal and overall. The internal is responsibility of the TRANSMIT partners participating to the TRANSMIT IS via a service . The overall is defined by the developers of the prototype presentation layer. It is beyond the scope of this article to expand further on the overall IT strategy, however SOA (Service Oriented Architecture) is briefly recalled as one of the best practices that are used within the IT strategy and is known to generate real business value. Moreover SOA supports the so-called “
SOA represents a paradigm shift in applications design, which includes decomposing business functions and application features into a set of independent but cooperative subsystems or services. This helps businesses to gain flexibility, reuse, and interoperability , which in turn implies reduction of operational costs, acceleration of the development of new application by leveraging shared service capabilities, minimization of operating errors and reduction of risks and disruptions to business . Finally, SOA can demonstrate business value and at the same time assess/fine-tune performance and model/modify processes through Key Performance Indicators (KPIs) .
No matter what the overall IT is going to be, SOA philosophy can be still applied for the development of various data services within the data layer. However it should be stressed that the development of the presentation and business layers dictated by the overall IT strategy, influences the developed of the data system which will realize the data layer, since it can pose unique requirements on the data system or require the design of new data services.
The strategy adopted for data management in the frame of TRANSMIT is broad in scope to allow flexibility given the evolutionary prototyping development methodology of the TRANSMIT IS (see Figure 3). Such choice will also benefit the IPDM prototype development by providing the capacity to the data layer to accommodate further business and application layers needs in terms of data management services. We begin this section by discussing the data and information needs of the TRANSMIT IS which capture the state of the IPDM prototype at the time of writing of this article. These needs should be frequently re-evaluated and the data strategy should be kept up-to-date.
The initial survey conducted shows that the prototype system relies on a variety of proprietary data files in ASCII & Binary format, originating mainly from GPS and Radio occultation satellites as well as other Space-borne instruments. The input and output products have either spatial (e.g. global TEC maps) or temporal dimensions (e.g. complex GPS RF-data) or in some cases both (global TEC maps, predicted over time). Regarding the complex GPS data per se, the size of data files can generate a huge bottleneck, if data movement is scheduled during the operation of the distributed system. Finally, outputs from theoretical models, implemented in different programming languages, have to be also provided (such as the ionospheric models IRI and NeQuick2, just to name a few).
Based on the above needs we have developed a general
A compelling vision for DM.
The mission and long-term directional goals of DM.
Short-term SMART (Specific Measurable Actionable Realistic Time-bound) DM objectives.
The TRANSMIT DM vision and mission is to realize an intelligent DM system that will offer benefits to the enterprise and its customers and leverage existing IT/DM activities. The main mission of the DM function is to meet and exceed the data/information needs of all stakeholders in terms of data/information
Data Architecture (DA) function
Data Development (DD) function
Data Operations (DO) function
Content Management (CM) function
Meta-data Management (MdM) function
Data Security Management (DSM) function
Data Quality Management (DQM) function
Finally, the short-term SMART DM objectives are listed below for each of the above-mentioned function.
Define the “data model”
Analyze and align with “business models”
Define data technology architecture
Define meta-data architecture
Analyze information requirements
Develop conceptual, logical and physical data models
Design physical databases
Design information products
Design access services
Implement development/test database changes
Create test data
Migrate and convert data
Build and test information products
Build and test data access services
Validate information requirements
Prepare for data deployment
Implement and control database environments
Obtain externally sourced data
Plan for data recovery
Backup and recover data
Set database performance service levels
Monitor and tune database performance
Plan for data retention
Archive, retain and purge data
Support specialized databases
Implement management systems for acquisition, storage, access and security controls of unstructured data
Backup and dispose unstructured data
Retain and dispose unstructured data
Understand data security needs and regulatory requirements
Define data security policy
Define data security standards, controls and procedures
Manage users, passwords and group memberships
Manage data access views and permissions
Monitor user authentication and access behavior
Implement a managed meta-data environment
Create and maintain meta-data
Manage meta-data repositories
Distribute and deliver meta-data
Define data quality requirements
Define data quality metrics
Define data quality business rules
Test and validate data quality requirements
Set and evaluate data quality service levels
Design, implement and monitor operational data quality procedures
6. Final remarks
In this paper we introduce the data management strategy formulated for the TRANSMIT project case. We hope that we achieved to clearly underline the overall requirements for both the IS/IT and data/information, and proposed feasible strategies to be implemented in TRANSMIT prototype in order to support the future GNSS services. To achieve the technical goals of TRANSMIT project, it is needed a flexible, secure, reliable, data system layer to be aligned with the business strategy and generate added value via operational excellence. The current development effort regarding the data system development is on the realization of meta-data repository, as well as on archiving of the necessary test-data, to be later on loaded on the database management system and become accessible from application developers. The data security function, has been implemented and its user interface can be accessed via . Finally, data access services have been developed and tested for different application regimes.
Eleftherios Plakidis is one of the three Experience Researchers in TRANSMIT project . The authors would like to thank Dr. Kees de Jong, and the rest personnel of Fugro Intersite B.V., for their valuable suggestions during Eleftherios Plakidis placement at the company’s offices and the insights they offered regarding the business needs of the company of ionospheric related services. This interaction contributed very constructively towards steering the business strategy of the TRANSMIT programme into the right direction.