Modeling Incremental Information of Topographic Database Based on OEM

The distribution of the update information of topographic database is still one of the main open challenges for many data producers. The incremental method is transfer of a data set that is restricted to objects which have been changed since the last transfer. This paper focuses on the modeling and description of incremental information, which is the precondition of distribution. In order to accomplish this task, firstly we analyze the characteristics of incremental information of topographic database. By analysis, we find out that the incremental information is semi-structured by nature. In this respect, this paper investigates the use of SSD (semi-structured data) models-an innovative approach recently developed in Information Technology-for modeling incremental information. A framework for the representation of geographic entities in OEM (Object Exchange Model), a popular model for semi-structured data, is introduced. Additionally, it is shown how to map the OEM representation of incremental information to XML (eXtensible Markup Language) description. Using XML to describe incremental information can help users understand this kind of information and update their databases. A simplified case study in the application domain of the distribution of topographical data is examined closely.