Metadata Information Systems for Geospatial Data

The more information and data are produced by the actual information society, the more important become mechanisms and systems which organize the data and include information where to find which data. Most popular peculiarities of such information systems are metadata information systems (MIS) and catalogue systems (CS). The main difference between these systems is the extent of the information spectrum covered. Whilst e.g. catalogues for department stores or phone books are typical representatives of CS covering a relatively clearly outlined information spectrum (address, phone number, article no., price etc.), other systems cover a quite larger spectrum. Examples for this are environmental MIS such as the UDK (German: Umweltdatenkatalog, engl.: environmental data catalogue, see Swoboda et al., 1999) on a national basis or GELOS (Global Environment Information Locator Service, see GELOS, 2000 and ETC/CDS, 1999) and EIONET (European Environment Information and Observation Network, see EIONET, 1999) on an European basis. This chapter describes general aspects around the topic, outlines typical strengths and problems of existing systems and gives some impressions about trends and current activities in the field of MIS for geospatial data. In the first part, some definitions and background information about the topic metadata and MIS are given. Then, different metadata tasks and views are listed: whilst from the user point of view, MIS are used as search engine in order to locate suitable data and to integrate it in current GIS projects, on the other hand geodata provider use it as marketing instrument - here MIS build the basis for E-Commerce applications. Afterwards, several examples of existing MIS and current activities and organizations involved in the field of MIS for geospatial data are presented. Finally, aside from a comprehensive summary, some trends referring to further development and technical research in that field are mentioned