Geography Markup Language (GML) becomes the de facto standard for geographic information representation on the
internet. GML schema provides a way to define the structure, content, and semantic of GML documents. It contains
useful structural information of GML documents and plays an important role in storing, querying and analyzing GML
data. However, GML schema is not mandatory, and it is common that a GML document contains no schema. In this
paper, we present Gstruct, a tool for GML schema extraction. Gstruct finds the features in the input GML documents,
identifies geometry datatypes as well as simple datatypes, then integrates all these features and eliminates improper
components to output the optimal schema. Experiments demonstrate that Gstruct is effective in extracting semantically
meaningful schemas from GML documents.
GML is an XML encoding for the modeling, transport and storage of geographic information, which has been making a
significant influential on the ability of organizations to share geographic information among their Web based GIS
applications. Ontology has been acknowledged to be the kernel methodology for capturing and sharing semantics of
spatial information. This paper proposes a framework for integrating spatial information based on GML schema
matching by using ontology technologies, in which GML is adopted as the common format for spatial information
wrapping and mediation, and ontology is used to overcome the heterogeneity when matching different GML schemas.
A prototype is also implemented based on the proposed framework.