Left-Right Relations for Qualitative Representation and Alignment of Planar Spatial Networks.

The spatial relations "left-of" and "right-of" are important for distinguishing relative positions of objects within and with respect to elements of plane embedded networks such as networks of streets. We present a representation of the "left/right" relations that is suitable for use in sketch-to-metric map alignment. The new representation is based on a new family of qualitative spatial calculi called ULST RA. Although left/right relations have already been formalized for line segments in the Dipole Relation Algebra (DRA) family of qualitative spatial calculi, the distinctions made by those calculi are too strong for applications such as sketch-to-metric map alignment. We show in an empirical evaluation that performing sketch-to-metric map alignment with the new representation is more effective than using the original DRA calculi.