CARDINAL DIRECTION RELATIONS QUERY MODELING BASED ON GEO-ONTOLOGY

Direction relations, as an important spatial relationship, is simply expressed as object prosperity in traditional geo-ontology. The lacking of explicit specifications and reasoning rules of direction relations in geo-ontology result in the difficult or inflexible of spatial reasoning. Also, digital gazetteers provide information on named features, linking the feature's name with its location and its type. Although the location information is incomplete and not exact, the implicit spatial information, for example spatial relationships and spatial scale, can be extract using the appropriate models based on geo-ontology. In this paper, we proposed a novel conceptual framework of direction relations in order to formalize the semantics and implicit information of direction relations, and present an extraction algorithm of implicit information based on previous researches, which will produce a complete query instance of direction relations. At last, the most suitable direction physical model is recommended to calculation module according to relevant rules. And the experimental results show that this direction query model not only extracted the implicit information effectively, but also made a reasonable interpretation for the user's intention.