OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible. This is an author-deposited version published in : http://oatao.univ-toulouse.fr/ Eprints ID : 18809 The contribution was presented at EKAW 2016 : Abstract. We propose an approach to semantically enrich metadata records of satellite imagery with external data. As a result we are able the identify relevant images using a larger set of matching criteria. Conventional methods for annotating data sets are usually based on metadata records (with attributes such as title, provider, access mode, and spatio-temporal characteristics), which offer a narrow view of the world. Enriching metadata with contextual information (i.e., the region depicted in the image has been recently affected by extreme weather) requires formalizing spatio-temporal relationships between metadata records and external data sources. Semantic technologies play a key role in such scenarios by providing an infrastructure based on RDF and ontologies.

The selection, acquisition, and management of digital data are now part and parcel of the work librarians handle on a day-today basis. While much thought goes into this work, little consideration may be given to the long-term preservation of the collected data. Digital data cannot be retained for the future in the same way paper-based materials have traditionally been handled. Specifi c issues arise when archiving digital data and especially geospatial data. This article will discuss some of those issues, including data versioning, fi le size, proprietary data formats, copyright, and the complexity of fi le formats. Collection development topics, including what to collect and why, will also be explored. The work underlying this article is being done as part of an award from the Library of Congress's National Digital Information Infrastructure and Preservation Program (NDIIPP).

There are many similarities between building a geospatial digital archive and building a hard-copy map collection, and two major ones are the necessity to have a collection development policy and the amount of hard work required to seek out and acquire the resources. Two institutions, University of California at Santa Barbara and Stanford University, the initial partners in the National Geospatial Digital Archives (NGDA), chose to collect digital data that was in line with each library's standard collection strengths and responsibilities. Collection development policies were written for the project as a whole and for each partner institution. While based on traditional paper map policies, these geospatial collection development policies are tailored specifically for digital data by including sections on metadata, versioning, file formats, proprietary formats, data set size, and ownership/access considerations.During the acquisition phase of the contract a considerable amount has been learned about file formats, data acquisition of compressed vs. uncompressed files, short-term storage prior to repository ingest, and metadata creation. While metadata creation at the collection-level/series-level has been relatively easy the acquisition phase has underscored the challenges inherent in creating accurate item-level metadata. One of the central findings of the NGDA experience is that format information is vital for long-term preservation. Thus, the need to understand file formats and specifications has led to the creation of a format registry specifically for geospatial materials.

No abstract