Research And Application Of Multi-scale Vector Polygon Elements Matching Method

Geographic Information Technology and biotechnology and nanotechnology as one of today's three major technology industries,Geographic Information System(GIS)technology plays an important role in data processing,integration and updating in different areas involved.China's basic geographic information system is based on the formation of digital information service industrialization model as the goal,through different technical means to obtain the basic geographic information collection,editing,storage,built multi-scale spatial database.With the deepening of the development of geographic information industry in China,how to achieve multi-scale spatial database integration update quickly and effectively is an important research problem,and vector data matching is one of the key technologies.Vector data matching is a technique to achieve spatial data matching by judging the similarity between attribute information,topological relations and geometric features of the same name entity.Duing to the importance of polygon elements in map data and the complexity of map representation,this paper focuses on the research of polygon elements matching,and fully analyzes the properties of geometric entities under the multi-scale conditions,such as attributes,geometric characteristics(position,geometry,Topological relations,the number of entities,the type of entity,etc.)and spatial relations,and the geometric characteristics of the opposite entities are described and compared in different ways and put forward different matching scheme and the vector matching in the incremental updating application does the corresponding research.Specific research contents are as follows:(1)In the description of the geometric features of the polygon elements this paper uses the geometric center method(center of gravity),the minimum circumscribed rectangle method(minimum bounding rectangular area and minimum external rectangle method),convex hull method and presents a precise description of the geometrical features of the polygon elements in the polar coordinate description method.For the complex polygon of geometric shapes,an improved Douglas-Peucker algorithm is used to simplify the shape of the entity,which improves the efficiency of the polygon elements description.(2)In the study of the method of polygon elements matching,the similarity of the same name is described by the overlap degree of entity area,distance difference and geometric similarity.Take a general description of the physical location of the center of gravity position method.For the multi-scale multi-entity situation,we propose a center-of-gravity method to obtain the geometric center of the entity.Using two-way area overlap method to obtain the solid area difference,and carries on the experimental analysis;In the study of solid shape similarity matching,proposed a method of polar coordinate vector contour feature points,calculate the same entity in the node and uniform sampling points distance difference,We will get the difference of the two as the final matching criterion.For the complex polygon elements is simplified by Douglas-Peucker algorithm,and the experimental results show that this method can solve the problem of the accuracy of polygon elements matching.(3)This paper fully consider the characteristics of multi-scale analysis of the polygon elements,the entity does not match the consistency in the data type case,matching the point target and area target and linear target and polygon target,and proposed solutions;In this paper,we propose a multi-scale entity matching strategy,such as one-to-one and one-to-many elements,and a method of obtaining the matching set of elements in a one-to-many match.In order to improve the accuracy of matching in this study,we consider the elements similarity index,and set the weights for the results of different matching methods.Using the weighted average method to obtain the comprehensive matching degree.(4)This paper analyzes the incremental updating model of the current database and its shortcomings,and makes a corresponding research on the incremental updating of the database elements,and applies the polygon elements research method to the incremental updating.Finally,the research result of this paper develops a simple data update system.