Research And Implementation Of Vector Tile Technology In Geographic Information Emergency Service

Geographic information services have evolved from the traditional provision of spatial location data and maps of various scales on the earth to multiple modern high-tech service systems that integrate real-time positioning technology,geographic information systems,computer networks,and database technologies.The geographic information service platform with WebGIS as the mainstream technology mainly provides users with online browsing and operation functions such as high-precision satellite images of grid tiles,map images,POI query,and route planning.Vector data such as roads are usually rasterized to provide services in the form of tile pictures.The biggest disadvantage of these methods is that the geographic information update process is complicated and inefficient,and cannot meet the real-time requirements of emergency geographic information services.This paper studies the vector data service in response to the requirements for timely updating of vector data in emergencies,builds the business logic of vector data services,tiles the vector data,and creates vector object indexes.Based on the Cesium development framework,the vector data in emergency geographic information systems Does not have topological relations,cannot edit in real time,designed and implemented a prototype of emergency geographic information vector data service system based on B / S architecture,and provided vector data services,supporting online loading and rendering of vector tile data,providing and remote sensing the functions of image overlay browsing,annotation,and online style custom modification,fulfill the requirements of visual browsing and temporary editing of online geographic information vector data in an emergency environment.The main results are as follows:(1)Based on the Google Maps tile scheme,researched the vector tile division algorithm,constructed the business logic of the vector data service,and realized the vector tile construction of national road network data;(2)Researched the relevant algorithms for efficient data call of tile data on the server side,introduced the server-side data cache mechanism,designed and published the vector tile data service online;(3)Designed and implemented the emergency geographic information vector data service system prototype with the open source Cesium framework,provided vector data services,and realized the online loading and rendering of vector tile data;(4)The text annotation display and style modification functions of the vector elements on the web page are implemented.