Funding for the GeoPortOst project was approved in 2014 by the German Research Foundation (DFG) as part of its support program for outstanding research libraries. In 2017, the second phase of the project (until 2019) began with the expansion of the geoportal to include additional thematic maps on Eastern and Southeast Europe with the participation of the Leibniz Institute for European History (IEG) and the Georg Eckert Institute - Leibniz Institute for International Textbook Research (GEI). This phase also included the implementation of a tool for linking the maps with qualitative and/or quantitative contextual data.
Maps are intermedial sign systems that can bundle and transport the most diverse information, and this was something the library of the Leibniz Institute for East and Southeast European Studies (IOS) and its predecessors recognized at an early stage. As a result, our special catalog of hidden maps serves as a unique tool for finding information. More than 27,000 hidden maps have been recorded on approximately 16,000 catalog cards. At the IOS, what are referred to as hidden maps are additional cartographic materials found in monographs, journals, and anthologies. The information on these maps, created at the IOS, has been transferred from analog form to digitally networked environments by integrating the catalog into the data infrastructure of the Bavarian Library Network. Constantly being added to, this catalog section is now slowly approaching 30,000 entries.
From the stock of maps listed in the catalog, 912 works were identified as being in the public domain by 2016, digitized and marked with authority files and notations (Dewey Decimal Classification) to disambiguate and increase interoperability. The map images were located in the GeoPortOst georeferencer by numerous skilled volunteers (crowdsourcing). The resulting geodata were imported into the catalog as metadata and serve to support geographically based retrieval approaches that enable visual term-independent searches.
The combination of bibliographic indexing and geographic reference has resulted in the development of the Geoportal, a cartographic information system in which maps as knowledge repositories are adequately represented in both their geographic and semantic dimensions and can be aggregated and reused as digital information objects.
In the second project phase, the map inventory of GeoPortOst was supplemented by retro-digitized maps, but also by born digitals, still copyright protected, from the holdings of the IOS, the IEG Mainz, and the digital collections of the GEI Braunschweig. Thematic maps, which make up the largest part of the holdings, are always contextual. They link a map image to a specific data basis. By using an annotation tool, the map-context relationship can also be reconstructed in digital form and made available for editing. This enabled us to create a data infrastructure in the project to enrich maps with meta and geo data as well as additional contextual data. Through the use of Sematic Web and Linked Data technologies, the aggregated information is made available for analysis and subsequent use.