Open Data and Collaboration

The INSPIRE roadmap states that compliant view services must be operational by 9th November 2011, over a year before download services. Because of this, how the different software solve the current view service issues may well have a large bearing on which software is adopted by NMCA̢۪s and other organizations affected by INSPIRE. Mainstream map servers such as Mapserver, Geoserver and Deegree are now in a race to see who can demonstrate the ability to provide INSPIRE compliant view services whilst fitting comfortably into adjusted data management systems.

Many best practice projects such as Esdin and Euradin have concentrated on download services so it is only now that members are beginning to think about view services. That has also been reflected by the main players in the FOSS field only recently beginning work on enabling their respective software to serve INSPIRE compliant WMS. Indeed at the time of writing only Deegree3 claims to be able to serve fully compliant services.

This presentation will compare the very different solutions offered by Mapserver, Geoserver and Deegree to the varied issues associated with INSPIRE view services. Other software will be considered if they demonstrate INSPIRE compliancy development work before September. Each software is built, maintained and developed using a different model, therefore each software̢۪s response to issues such as multi-geometry layers, extended service metadata and multilingualism will themselves be diverse.

A service created using each of the software will be looked at and INSPIRE compliancy analyzed through comparison with the ‘Technical Guidance for the implementation of INSPIRE view services’ document. Results will be considered primarily with regards mandatory requirements, but important optional requirements will also be taken into account.

The Spatial Data Access Tool (SDAT, http://webmap.ornl.gov/wcsdown) developed at the Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC) and the Modeling and Synthesis Thematic Data Center (MAST-DC), both NASA-funded projects, provides visualization and access to a variety of biophysical, vegetation, elevation, ecosystem, climate, soil, and model data sets using Open Geospatial Consortium (OGC) services and open source software.

The SDAT is built on a 3-tier architecture: data, logic, and presentation tiers. The data tier includes PostgreSQL-based ArcSDE spatial databases and regular file systems storing geospatial data in non-proprietary file formats, including GeoTIFF and netCDF. The backbone of the logic tier is a cluster of OGC Web Map Services (WMS) and Web Coverage Services (WCS), which provide on-demand visualization and access to geospatial data stored in the data tier in different spatial/temporal extent, projection, resolution, and data format. The WMS and WCS are built on top of MapServer and enhanced with automatic mapfile generation to ease the ingest of new data into these services. The main component of the presentation tier is a Web application client that utilizes the services from the logic tier. This Web application provides features that allow users to conveniently search for data, view both dataset-level and granule-level metadata, visualize data, and access data. The presentation tier provides a WMS-based interactive map widget, which is built with OpenLayers that allows users to visualize geospatial data. Another component of the presentation tier is an OGC Keyhole Markup Language (KML) link to visualize geospatial data in Google Earth or any KML-compatible client.