Spatiotemporal Data Spatial Integration Based On Global Grid

With the rapid development of modern technology and the high-speed integration of geographic information technology and other professions,GIS spatio-temporal data plays an important role in all industries.However,different industries or sectors produce data for different purposes,ways and uses,resulting in large differences in spatial reference of spatio-temporal data from different sources,making it difficult to share and utilize the data between industries or sectors.For this reason,it is urgent to realize the sharing and utilization of this kind of data.Most of the existing studies on data sharing focus on the unified organization and management of metadata or spatial data and external services,with less attention to the inconvenience of data sharing caused by different spatial references.Based on the team’s previous work,this thesis investigates a spatio-temporal integration method based on the global grid and oriented to vector-grid type data for its spatial mapping inaccuracy and lack of support for temporal data and vector data,mainly as follows:(1)To address the problem that the mapping model in the existing spatial integration research is not accurate enough in the projection deformation region,a grid-adaptive spatially accurate mapping model is proposed,and relevant experiments are designed to investigate the spatial mapping accuracy of the mapping model and its construction cost.The experiments show that the model can achieve the accurate mapping between the data space and the grid space in the larger deformation area with less cost than the original model.(2)To address the problem of temporal dimension of data not taken into account in existing spatial integration studies,a temporal grid model is first introduced and designed as a unified framework for subsequent spatio-temporal integration by combining the existing spatial grid with temporal encoding.On this basis,a data table structure with indexing and exact mapping and the corresponding retrieval method are designed in conjunction with the spatial exact mapping model to realize the spatio-temporal integration of multi-source raster data and carry out the corresponding experimental validation.(3)To address the problem that the existing spatial integration research does not take vector data into account,firstly,an ORB-ST index for spatio-temporal retrieval of vector data is proposed based on the spatio-temporal grid model;on this basis,the spatio-temporal integration method of vector data is given in combination with the spatial exact mapping model,and a prototype system is developed to realize the spatio-temporal integration of multi-source vector data.During the period,the experiments explore the performance indexes about indexing aspects such as maximum level grid selection,index memory consumption comparison with QRB+index as reference,index retrieval efficiency and the feasibility verification about the spatio-temporal integration method of vector data.There are 54 figures,14 tables and 87 references in this thesis.