Font Size: a A A

Research On Spatial Data Index Technology And Its Application

Posted on:2004-06-02Degree:MasterType:Thesis
Country:ChinaCandidate:Y H WuFull Text:PDF
GTID:2168360095956760Subject:Computer application technology
Abstract/Summary:PDF Full Text Request
The Spatial Data Index Technology is of significance in researching into CAD/CAM, GIS, Image process, VRML, digital earth and many other fields. It can provide technological support for accessing images in GIS, offer theoretical basis for analyzing and managing space relation, and give spatial database designers helpful references for adopting data structure.This thesis discusses spatial data index first, shows the history of spatial index structure, introduces the current domestic and foreign main index structure in GIS's spatial joining, and then makes use of character to express spatial object. Qualitative description is often used to understand, analyze and conclude about spatial environment in large scale space and everyday life. Qualitative description can deal with unaccurate data and simplify the description and reasoning process. The representation model of spatial relation and its expression are mostly qualitative in the current GIS, and natural language description often adopts the qualitative method. The quantitative method of spatial data is apparently different from the method of people's concluding about spatial relation and not in accordance with spatial cognition. This thesis is intended for the introduction to the qualitative spatial analysis of spatial object in two-dimensional space by using character.This thesis mainly discusses spatial relation of simple area object in two-dimensional space, the methods of spatial data index in GIS and the application of spatial data index. This thesis introduces a method of spatial data index based on character and its application to spatial relation analysis of spatial object. The classical R-tree as index is adopted in spatial joining. R-tree is performed by bulk loading. In order to perfect performance efficiency, the MBR of spatial object is ordered by the Hilbert ordering code of the center of spatial object's MBR. Practice shows that this method gets best query performance. When refining the candidates, the author gets rid of traditional complicated geometric calculating. This thesis sets forward a new query model based on character. This model changes two-dimensional spatial object into one-dimensional string to process, and therefore turns two-dimensional disorder query into order query by using heuristic querying algorithm so that bisearch is used to improve query efficiency greatly. It is proved that string is relatively effective on expressing direction relations of spatial object. Based on the projection of spatial object,two one-dimensional strings are produced. Analyzing these strings and using spatial direction relation matrices, we could further revise the direction relation. As a result the relative direction relation of spatial object is obtained.
Keywords/Search Tags:spatial index, spatial analysis, spatial join, direction relation
PDF Full Text Request
Related items