by Javier Nogueras-Iso, F. Javier Zarazaga-Soria & Pedro R. Muro-Medrano
Springer ISBN: 3540244646 2005. 274 p. PDF 4.3MB
Metadata play a fundamental role in both DLs and SDIs. Commonly defined as "structured data about data" or "data which describe attributes of a resource" or, more simply, "information about data", it is an essential requirement for locating and evaluating available data. Therefore, this book focuses on the study of different metadata aspects, which contribute to a more efficient use of DLs and SDIs. The three main issues addressed are: the management of nested collections of resources, the interoperability between metadata schemas, and the integration of information retrieval techniques to the discovery services of geographic data catalogs (contributing in this way to avoid metadata content heterogeneity).
The Geographic Information (GI), also known as geo-spatial data, is the information that describes phenomena associated directly or indirectly with a location with respect to the Earth surface. Nowadays, there are available large amounts of geographic data that have been gathered (for decades) with different purposes by different institutions and companies. For instance, the geographic information is vital for decision-making and resource management in diverse areas (natural resources, facilities, cadastres, economy...), and at different levels (local, regional, national or even global) (Buehler and Mc-Kee, 1996). Furthermore, the volume of this information grows day by day thanks to important technology advances in high-resolution satellite remote sensors, Global Positioning Systems (GPS), databases and geo-processing software notwithstanding an increasing interest by individuals and institutions. Even more, it is possible to georeference complex collections of a broad range of resource types, including textual and graphic documents, digital geospatial map and imagery data, real-time acquired observations, legacy databases of tabular historical records, multimedia components such as audio and video, and scientific algorithms.
In recent years nations have made unprecedented investments in both information and the means to assemble, store, process, analyze, and disseminate it. Thousands of organizations and agencies (all levels of government, the private and non-profit sectors, and academia) throughout the world spend billions of euros each year producing and using geographic data (Somers, 1997; Groot and McLaughlin, 2000). This has been particularly enhanced by the rapid advancement in spatial data capture technologies, which has made the capture of digital spatial data a relatively quick and easy process. Additionally, it is also worthwhile mentioning the impact of the Internet in the distribution of geographic information resources. As well as other information resources, lots of geographic information resources are also available on the Internet. And in some cases it is even assumed that the own Internet is the storehouse of this information.