【作者】 李学东；

【导师】 管志宁； 张明华；

【作者基本信息】 中国地质大学（北京） ， 地球探测与信息技术， 2009， 博士

【摘要】 为促进地质资料更好地服务于矿产资源的开发和利用,地质资料社会化服务变得非常重要,地质资料网络在线服务更是发展的潮流。随着互联网技术和应用的发展,WebGIS技术已逐步成为地质资料网络发布的主要手段,但由于传统WebGIS地图发布技术存在响应速度慢、占用带宽高、交互能力差等问题,不能满足海量地质资料在线服务的要求,已成为制约地质资料社会化服务的技术瓶颈。同时,地学数据具有多源、异构、分布的特点,地质资料共享和集成发布也是目前工作中亟待解决的问题。为解决上述问题,本文分析了传统WebGIS技术存在的问题,深入研究了REST(Representational State Transfer,表述性状态转移)架构思想和AJAX(Asynchronous JavaScript and XML,异步Javascript和XML)技术,创新地提出了基于栅格数据预切分和矢量数据预渲染的地图发布技术;并在此基础上,实现了多源地学数据的共享和集成发布服务。本文的主要贡献与创新之处体现为以下几点:(1)地学栅格数据预切分发布技术。提出了基于栅格地图预切分的发布思想,设计了地图切分规则和地图切片存储结构,实现海量地图切片的快速检索;设计了地图切片请求、地图切片合成的流程和相关算法,实现快速地图浏览;设计了地图切片的窗口缓存、浏览器缓存和服务器缓存,通过缩短访问路径和减少访问次数,来提高系统性能。(2)地学矢量数据预渲染发布技术。提出了基于矢量数据预渲染的发布思想,实现了矢量数据预渲染底图与矢量专题数据相结合的发布技术。预渲染底图发布给用户提供了高质量的栅格底图,专题数据发布给用户提供了动态查询功能,将两者优势结合,以提高矢量数据发布的图形质量和交互查询能力。(3)面向Web服务的地学数据集成发布技术。在栅格数据预切分发布技术和矢量数据预渲染发布技术的基础上,提出了基于OGC网络服务的多源地学数据集成发布技术,实现了多源地学数据的动态加载、多图层叠加、透明度控制、地图浏览、数据查询等发布服务,为地学数据在线综合解释提供了辅助工具。基于上述技术和方法,自主设计和开发了原型发布系统。并经过对全国1:250万地质图、重力图、航磁图的叠加发布测试,验证了此系统能显著提高海量地学数据的发布速度,实现平滑的地图浏览,并具有灵活的数据查询和交互能力,充分满足地学数据在线发布服务的需求。更多还原

【Abstract】 For the sake of serving the exploration and utilization of mineral resources better, now it’s of vital importance to make geological data serve the society, and nowadays there is an apparent trend to share geological data over internet.Currently, the WebGIS technology is the major method used in this area. However, this traditional WebGIS technology has obvious weaknesses of slow publishing speed, high network traffic and poor interaction ability. In this case, it can’t meet the needs and demand of online service of massive geological data. This problem has become the bottle neck of its development. Meanwhile, the geological data has its own particular characteristics such as being multi-sourced, heterogeneous and distributed. Therefore, it is urgent to solve out this problem and get the data shared and published sufficiently and effectively. Focusing on this problem, this thesis first gave a thorough analysis of the weaknesses of the WebGIS technology, then researched the REST framework and AJAX technology, and finally provided a new map-publishing technology with a combination of pre-generated raster map tiles and pre-rendered vector basemap in which the integration and publishing service for multi-sources of geological data has been implemented. The main contribution of this thesis is summarized as below.The first point is about the publishing technology of geological raster data based on pre-generated map tiles. This thesis provided the publishing idea of pre-generated map tiles and developed the rules of generating map tiles and storage structure of map tiles, and finally made the retrievement of massive map tiles quicker. It also studied the flow of map tiles request and integration and related algorithm and made the map browser go faster. Meanwhile, it delivered a new designing of map window cache, browser cache and server-side cache to improve system performance by shortening access path and decreasing access times.The second point is about the publishing technology of geological vector data based on pre-rendered vector basemap. It put forward the publishing idea of pre-rendered vector basemap and made a combined technology of pre-rendered basemap and thematic vector data come true. Pre-rendered basemap publishing affords users high quality image and thematic vector data publishing affords users dynamic data query. With the combination of the two technologies’advantages, the quality of map publishing and the ability of interactive query have been improved.The third point is about geological data integration and publishing technology. On the basis of raster data pre-generated publishing technology and vector data pre-rendered publishing technology, it put forward multi-sources geological data integration and publishing technology based on OGC webservices and implemented multi-sources geological data’s dynamically loading, multi-layers stacking, transparence controlling, map browsing and data querying, and other publishing services and finally provided assistant tools for geological data online integration interpretation.Based on the above technologies and methods, the design and development of a prototype system has been carried out independently. After testing the integrated publishing of 1: 2,500,000 scale geology map, gravity map and aeromagnetic map, it has been validated that this system can apparently improve massive geological data publishing speed, make map browser go smoothly. The system also has flexibility on data query and interaction so that it has completely met the needs and demand of current geological data online serving.更多还原