dc.description.abstract |
Describing structures of geospatial objects as models is essential for understanding
geographic processes. Efforts to develop such models started from decades ago but a
model for 3D spatial-temporal (3D space plus 1D time) objects has not been well
formulated. This dissertation describes the formalization of a spatial-temporal data model
for managing 3D spatial-temporal objects. This model extends the spatial-temporal
Object-Oriented model by incorporating a behavioral description to the definition of the
spatial-temporal objects to better characterize the dynamics of these objects. Besides,
spatial-temporal rules and conditions, which are expressed as constraints, are integrated
as important components of the model. These rules and conditions serve as the
foundations of maintaining data integrity and enabling complex spatial-temporal queries.
A set of constraints related to the spatial-temporal characteristics of 3D spatial-temporal
objects were identified and defined. The conceptual model served as the theoretical basis towards the building of a
Geographic Information System (GIS) for managing 3D spatial-temporal objects. Based
on the conceptual model, a prototype system was developed that provides interactive data
management and query functions for 3D spatial-temporal objects. A subset of spatialtemporal
constraints identified in the conceptual model were captured and formalized
through extended 3D computational geometry algorithms to ensure data integrity and
facilitate spatial-temporal queries. Using the dynamic repartitioning of airspace sectors as
a case study, this research shows that the proposed framework is effective to solve
problems involving 3D spatial-temporal objects. |
|