The main objective of this research project was to assess the quality and feasibility of the guidelines for INSPIRE Network Services. The completeness, clarity, consistency and ease-of implementation of the guidelines were considered. Part of this assessment is also the question: how can INSPIRE compliance be tested and measured? The topic was tackled both from a theoretical and a practical point of view.
The theoretical part of the project included a detailed investigation and assessment of the INSPIRE requirements and recommendations as regards: technical architecture of the services, functionality of the particular network services, quality of services, rights management issues, elements of spatial data and metadata models. This part of the project has been finalized with the synthesis of the guidelines derived from the INSPIRE documentation.
The review of the INSPIRE documents showed that these guidelines are specific and clear enough in most points, however not yet complete. The status of work as regards the technical guidelines for particular INSPIRE Network Services is different. The topic which calls for particular attention is the adaptation of the INSPIRE services to SOAP bindings. Another item that is needed and that is currently missing in the guidelines is the provision of more strict rules for compliance testing (Abstract Test Suites (ATS) for INSPIRE services and data) and quality of service (QoS) testing.
The practical part of the project was the implementation of some prototype View and Download services. For the implementation of the prototype services existing software was chosen, namely GeoServer, one of the spatial data server products implementing the OGC standards. The specific scenario chosen for the case study are web services for a national park. The spatial data for the prototype was acquired from the resources of the Narew National Park (Poland).
The prototype was realized in order to validate and evaluate whether the Implementing Rules and other guidelines contained all necessary information to set up INSPIRE compliant web services, with special attention to the question how this ‘compliance’ can be measured using both manual and automated testing methods. First, the prototype has been evaluated for the compliance with INSPIRE guidelines by manual inspection of the prototype services. Secondly, the compliance test methodology proposed by OGC has been used to perform automated tests on the GeoServer instance.
The evaluation of the prototype showed that the web services provided with GeoServer fulfill the majority of requirements for View/Download Services through the WMS/WFS functionalities (mandatory operation parameters, offered output formats etc.) Some elements need to be configured within GeoServer (e.g. the required spatial reference system, layer/feature type names that conform to the INSPIRE data specifications). Still, some INSPIRE-specific extensions to the functionality provided by GeoServer are needed for both services (support of the SOAP/POST methods for the service operations, solutions for multilingual aspects of services and rights management). Another requirement for the INSPIRE-conformant web services is that the spatial data and metadata are provided compliant with the data models required by INSPIRE.
The study on compliance testing methodologies is followed by the recommendation that the standards and testing programs from ISO and OGC can be of particular relevance for the development of Abstract Test Suites for INSPIRE services. The reference framework for INSPIRE compliance testing can be partially based on the OGC Compliance & Interoperability Testing & Evaluation Initiative (CITE) testing program. The OGC tests are especially suitable as reference since the core technical specifications for implementation of the particular INSPIRE Network Services are the OGC web services specifications.