Quality Assessment of Road Databases Using Aerial Imagery

Digital road databases are widely used in many facets of our daily life. Most of these databases come with a nominal quality indication, but often more detailed quality descriptions regarding possible errors, the positional accuracy, and information on the completeness of the vector data are desirable. In this paper an approach for the quality description of road data from the Authoritative Topographic Cartographic Information System (ATKIS) of Germany is introduced. The work is embedded in a project initiated by the German Federal Agency for Cartography and Geodesy (BKG), which is interested in an automation of the road data verification process. How existing road vectors from ATKIS can be assessed by combining the information coming from several object extraction algorithms is investigated. These objects are modeled in the so called relationship model where the topologic and geometric relation between roads and other objects are given. For example a row of trees is often parallel to roads and has a minimum and a maximum distance from the carriageway. Every extracted object such as rows of trees extracted from aerial imagery may then support a given ATKIS road. If it does not coincide with the model it gives evidence against the ATKIS road. The Hint-Theory is used which is derived from the Dempster-Shafer Theory of evidence to combine all information related to an ATKIS road segment. Example results show that the introduced procedure is able to yield reliable information on the quality of ATKIS objects.