A scale-explicit model for checking directional consistency in multi-resolution spatial data

Abstract

Multi-resolution spatial data always contain the inconsistencies of topological, directional, and metric relations due to measurement methods, data acquisition approaches, and map generalization algorithms. Therefore, checking these inconsistencies is critical for maintaining the integrity of multi-resolution or multi-source spatial data. To date, research has focused on the topological consistency, while the directional consistency at different resolutions has been largely overlooked. In this study we developed computation methods to derive the direction relations between coarse spatial objects from the relations between detailed objects. Then, the consistency of direction relations at different resolutions can be evaluated by checking whether the derived relations are compatible with the relations computed from the coarse objects in multi-resolution spatial data. The methods in this study modeled explicitly the scale effects of direction relations induced by the map generalization operator – merging, thus they are efficient for evaluating consistency. The directional consistency is an essential complement to topological and object-based consistencies.

Keywords:

• geographical information systems
• direction relations
• regions with parts
• multi-resolution spatial data
• directional consistency

Acknowledgements

We are grateful to the referees of this paper whose comments and suggestions have led to substantial improvements. The work presented in this paper was supported by grants from the National Natural Science Foundation of China (No. 40801190), the National High Technology Research and Development Program of China (No. 2008AA12Z209), and Key Laboratory of Geo-informatics of State Bureau of Surveying and Mapping (No. 200801).