Geographic Information Retrieval based on Two Orthogonal Criteria

A Geographic Information Retrieval (GIR) model is defined and the architecture of a GIR system, named Geo-Finder, is described. The GIR system is constituted by two main modules. The geo-indexing module applies bipolar criteria to automatically identify the geo-reference focus (footprint) of textual documents., The geo-retrieval module applies a context dependent matching function to evaluate queries consisting of two orthogonal constraints, a content constraint and a spatial constraint; the spatial constraint is defined by modeling the user’s perception of geographic “closeness” between the documents’ footprint and the query footprint. For each retrieved document, two relevance scores are computed with respect to the two query conditions, that can be combined to generate an overall ranked list of documents in a flexible way, by allowing users to specify a trade off between them.