A geographic knowledge representation system for multimedia geospatial retrieval and analysis

Digital libraries serving multimedia information that may be accessed in terms of geographic content and relationships are creating special challenges and opportunities for networked information systems. An especially challenging research issue concerning collections of geo-referenced information relates to the development of techniques supporting geographic information retrieval (GIR) that is both fuzzy and concept-based. Viewing the meta-information environment of a digital library as a heterogeneous set of services that support users in terms of GIR, we deffine a geographic knowledge representation system (GKRS) in terms of a core set of services of the meta-information environment that is required in supporting concept-based access to collections of geospatial information. In this paper, we describe an architecture for a GKRS and its implementation in terms of a prototype system. Our GKRS architecture loosely couples a variety of multimedia knowledge sources that are in part represented in terms of the semantic network and neural network representations developed in artifficial intelligence research. Both textual analysis and image processing techniques are employed in creating these textual and iconic geographical knowledge structures. The GKRS also employs spreading activation algorithms in support of concept-based knowledge retrieval. The paper describes implementational details of several of the components of the GKRS as well as discussing both the lessons learned from, and future directions of, our research.