Mixed Display Of Multiple Map Data Based On HTML5

With the fast fierce development of electronic map,geographic information,enrich the map data format is also increasing,lead to the map data compatibility between different application sharing is difficult.Vector data in different formats and different sources of map grid data cannot be used to study the problem of compatibility,puts forward the support geographic data source and format mixed use of web map service.In this paper,the research results mainly embodied in three aspects:(1)put forward by using pyramid map tiles vector model of geographic information,including the basic map data,real-time traffic data in stratified lean,and according to Google XYZ index number,unification on the basis of the standard image tiles.The vector of the interface design more portable,OpenStreetMap is better than that of foreign excellent map on the design.(2)engineering in HTML 5 as a MAP development platform,using its support JavaScript and Canvas support,the advantage of the open standard MAP services for engineering design,build a set of cross-platform VIMAP mixed MAP(Vector and Image MAP).With independent research and development of vector map data rendering engine,can carry on the real-time rendering of vector data on the client side,provides three kinds of vector data,a mixture of four different sources of maps tiles showed that increased the time-sharing traffic information query and hierarchical,and solved the geodetic coordinate system WGS-84 to GCJ-02 road conditions(layers)migration problems.VIMAP maps is compatible with different terminal has cross-platform display web map service,through the typical regional test,inspection,and has carried on the performance comparison with the domestic and foreign outstanding map.(3)put forward a multistage cache map tiles transport mechanism,effectively reduce the data with the server interaction,improve the client on the efficiency of vector data real-time rendering.Vector geographic data server provides storage and hierarchical vector tiles,and realize the grid tiles agent service,the client browser's cache design the map operation control module,realize the scale,drag and drop,direction,and other functions,and implement efficient cache update based on map control.Comprehensive multi-level cache data transmission experiment was carried out.This paper has solved the different map data format compatibility on display.Designed a variety of map data based on HTML 5 mixed display applications,provides more abundant than single grid or vector map map data show.