Study Of Object Oriented Spatio-Temporal Data Model

Conventional GIS only describes the geographical space statically with space and thematic attributes. With the dramatic increase of geographic information, especially the wide use of time dimension, human began to make scientific researches on Temporal GIS. Building appropriate spatio-temporal model can offer the tools that model and analyze the space, time and thematic attribute, and hold the history or forecast the future of geographical events.The thesis introduced the content about spatio-temporal modeling first. From human cognition to the real world, we introduced the concepts of space and time in geographical world, and discussed some important and basic notion, such as the characteristics, types and structures of spatial data, time model, time representation and time granularity, which related with the spatio-temporal model. By discussing spatio-temporal processes and movement types of the phenomena of geography, the notion of spatio-temporal model was educed. Paper reviewed the spatio-temporal conceptual models that have been developed such as time-space cube model, sequent snapshot model, base state with amendments model, space-time composite model, event based spatio-temporal model and object oriented spatio-temporal model, and pointed out their characteristics.The thesis analyzed and compared the advantages and disadvantages of conventional object oriented modeling method and introduced a totally new modeling method—Object-Role Modeling (ORM) for discussing object oriented modeling method. Paper introduced the characteristics and canonical process, and emphasized advantages of ORM in expressing the complex operation rules relative to another modeling method. Paper discussed in brief the advantages and disadvantages of ER,UML and ORM.Finally the thesis discussed the design of spatio-temporal object model of cadastral management system in conceptual level, logistic level and physical level based on analyzing spatio-temporal characteristics of cadastral data. Paper discussed particularly the procedure of building cadastral spatio-temporal object model by ORM method and introduced in brief the method of spatio-temporal query in cadastral system.