Research On Vector Tile Construction Method To Improve Network Transmission Efficiency

In the development of Web GIS,how to improve the transmission efficiency of spatial data on the Internet and the rapid display on the client,enhance the interactivity of map and make the user experience better is an inevitable and urgent problem to be solved.At present,the grid data transmission problem has been greatly solved by the grid tiles technology,and the technology is applied to various fields.Due to the characteristics of raster data,the Web map applications with raster data are difficult to meet the growing demand for the interactivity of map.Thus,research on the network transmission of vector data is the inevitable trend of Web GIS development.Based on the thought of grid tiles,the paper combines the spatial distribution density of vector data,takes the organization method based on tiles for vector data as breakthrough point,and launches an extensive research about the network transmission of vector data.The main contents are as follows:1)Research the Web GIS technology and the transmission mechanism of geospatial data.Propose an organization method for vector data based on vector tiles by the idea of pyramid model,which is helpful to solving the data quantity problem of progressive transmission.2)Promotes a method for vector tiles generation considering the spatial distribution density of features.The author proved the method can improve the loading and rendering efficiency and obtain a better user experience through the experiments.3)According to the characteristics of vector data,the paper promotes the methods for the clipping and combination of vector data organized by tiles,the processes of which are presented in detail.The methods provide the basis for the construction of vector tiles on the server side and the rendering of vector tiles on the client side.And the paper realizes the rendering of vector tiles based on Htlm5 Canvas.In last part,the dissertation used the method of organization and network transmission of vector data considering spatial distribution density of features,built a web map service,which was used in actual project called Rural Land Contract Management Information System of Zhejiang Province.