The Study On The Spatio-Temporal Data Model For Spatial Moving Objects

The means for obtaining space information are being abundant increasingly and the processing abilities are strengthening continuously, and then the description of geography information is changing toward dynamic, multi-dimension and visualization from static maps. The building of the spatio-temporal data model would be one of the important researches. However, the proposed spatio-temporal models lack the expression to the continuous changes of spatial objects mostly, so this paper is to consider the space and time factors comprehensively, study the spatio-temporal data model that can express the continuous changes and discrete changes of space objects, i.e. moving objects data model (MODM), and experienced and systemically analyzed the several related theories and technique. The main contents include:1. Systematically analyzed and discussed the chronon, temporal element, relations between temporal elements etc. temporal database theories, and the methods to express temporal information in relational databases and object-relational databases, i.e. tuple versioning and attribute versioning.2. Studied the influence of the time factor and the space factor to the traditional relational algebra and the operations after space and temporal expanding, and put forward and carried out data operation methods. Discussed and generalized the rules of logical design of spatio-temporal database with multi-granularity after spatio-temporal expansion. Designed and implemented the spatio-temporal expanded predicates for spatio-temporal data operations.3. At the foundation of deep analyzing the spatio-temporal data model for expressing spatial moving objects proposed by Guting et al., improved the data model. On the improved data model, experimented with the time-based, spatial-based and saptio-temporal-based data queries and spatio-temporal data visualization, which proved that the improved data model had the expressive ability for expressing the spatial moving objects with continuous changes.4. Designed and implemented the spatial moving object management prototype system used for the management, queries, and visualization of the spati-temporal data. The experiments on this prototype system indicated that the spatial moving object spatio-temporal data model proposed in this paper was correct, feasible, and effective for expressing spatial moving objects.