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Based On Spatial Data Storage And Retrieval Of Geospatial Research

Posted on:2007-09-18Degree:MasterType:Thesis
Country:ChinaCandidate:X L HanFull Text:PDF
GTID:2208360182978975Subject:Pattern Recognition and Intelligent Systems
Abstract/Summary:PDF Full Text Request
With the development of GIS and computer network technologies, the geospatial data management has been more and more available in all kinds of special domains. The storage of spatial data and attribute data and spatial indexing , which are the core issues of GIS, are integrated together to improve the efficiency of spatial query and processing.XML is easy and convenient to describe structured data, so XML becomes a means to storage and express data. Firstly, the paper describes spatial object in XML, and then XML object is stored in a relational database. Secondly, the paper provides an overview of spatial index technologies, discusses the two spatial index mechanismsin details——Quadtree index and R-trees index. Quadtree index is the spatial indexmechanism based on the geographical division of space, which must know in advance the scope of the distribution of objects in space. And R-trees index is based on the division of space objects, and there is no need to know in advance the distribution of objects in space, and index entries are based on the Minimum Boundary Rectangle of space object.As the query of spatial database, the paper uses two step query mechanism: the first, through using index candidates are queried to set out targets, and then the precision assembly of the candidates will derive precise targets. The paper presents three methods of spatial queries: Spatial Select Query, Spatial Joint Query, and Nearest Neighbor Query. And spatial index structures are used in the above three queries, so the paper implements Spatial Select Query based on R-trees, including points query and region query, Spatial Joint Query based on R-trees and Nearest Neighbor Query based on R-trees.Finally, the paper accomplishes design of the ISTP GisBuilder system, which is divided into five modules: data input, graphics and text editing and mapping, data storage and management, spatial query, spatial analysis. And these modules are implemented as five classes, including map layer object class, spatial relations class, spatial operation class, spatial index class, spatial query class.
Keywords/Search Tags:Geographic Information System, spatial index, spatial query, R-trees index, Quadtree index
PDF Full Text Request
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