Automatic Constraint For Ensuring Quality Of Geographic Data
Free (open access)
M. Casanova, R. Van der Straeten & T. Wallet
Geographic data is the backbone of sophisticated applications such as car navigation systems and Geographic Information Systems (GIs). Thus, the necessity of having geographic data with a high degree of quality - defined as its well-formedness and integrity - arises very quickly. However, the previous is not so easily ensured. Nowadays it is usual to find the quality ensuring constraints hard-coded in the quality check module of the GIS production environment, which results in a loss of expressiveness and makes mainte- nance more difficult. In our approach the quality constraints, which are expressed declaratively in the Object Constraint Language (OCL), contain relations between concepts of an explicit conceptual model of the geographic domain. The use of OCL makes the constraints modular, explicit, high-level and easy to review by the domain experts. We have built a code generator tool for translating the quality constraints into pieces of executable code. This code is inserted into the quality check module in order to be executed against the geographic data of the GIs. We have used the GeoObjects system - the geographic database and production environment of our industrial partner Tele Atlas- for validating our ideas. A set of quality constraints have been translated in our code generator tool and tested against real geographic data using the mentioned GeoObjects system.