InGrid 1.0 – The Nuts and Bolts of PortalU

Abstract

After the official launch in May 2006, PortalU will act as the new internet portal of the German environmental authorities. The “U” in PortalU stands for “Umwelt”, the german word for the environment. PortalU will provide access to government-owned environmental information of the 16 federal German states and the German federal government. The application replaces the actual “German Environmental Information Network” gein® (Vögele et al. 2004). Moreover, the “Virtual-UDK” (Swoboda et al. 1999), currently acting as the top-level environmental metadata query component of the German environmental authorities, will be merged with PortalU. The well-established UDK metadata model, however, will retain its importance as de-facto standard within the environmental community in Germany. Hence, the ISO19115 and ISO19119 compliant model builds the basis of the metadata component of PortalU. The step from gein® and the Virtual-UDK to PortalU is accompanied by a complete technical redesign which will enhance the functionality of the PortalU predecessors in many aspects. This new set-up is needed to include, as required by the new EU-directive 2003/4/EC on public access to environmental information (EU 2003), a much larger number of providers of environmental information, including agencies on the local level. It is also needed to be able to provide better access to environmental information that is not yet online or belongs to the so-called “hidden web”. Our paper describes the concepts and architecture of the software behind PortalU: InGrid 1.0. The name InGrid relates to “Information Grid”, pinpointing to the distributed approach of the new system. To support direct access to environmental data and metadata, the new system architecture features distributed indices based on highly adaptable database interfaces and a self-administrating peer-to-peer communication infrastructure. A number of standardized interfaces, including a web catalog service conforming to ISO and OGC standards and recommendations enable PortalU and other InGrid information nodes in the network to benefit from and contribute to other data infrastructures, for example the German national geodata infrastructure GDI-DE and the EC INSPIRE initiative (RDM Working Group 2002).