Symbol Representation for the Directions of Spatial Objects

Because of the complexity and uncertainty inherent in spatial problems, the description of the spatial relationship often adopts qualitative methods .Direction is a kind of important spatial relationship, it plays an important role in the process of spatial modeling, spatial query, spatial analyzing and spatial reasoning. In this paper, a new method of qualitative direction determinant based on the projection model and symbol representation is proposed, and a kind of simple and valid coding method based on the direction relationship is presented.