【作者】 蔡畅；

【导师】 崔铁军；

【作者基本信息】 解放军信息工程大学 ， 地图制图学与地理信息工程， 2011， 博士

【摘要】 三维地理信息网络服务既能体现地理信息网络服务进一步扩展的强烈需求,又能给三维空间信息的共享、互操作和集成提供新的解决方案,其研究具有重要的实际意义。针对目前的研究现状中存在的问题,本文从认知抽象模型的角度提出了三维地理信息网络服务的相关理论,并以此为指导提炼了三维地理信息网络服的几个关键技术问题,对其进行了系统性的研究,最后对研究内容进行了实验和测试。论文的主要工作包括:1、从地理信息网络服务发展的必然趋势出发,指出了三维地理信息网络服务研究的意义,分析了网络三维GIS、地理信息网络服务、三维地理信息网络服务的现状和已有的理论、技术成果,概括了本文需要研究的主要内容。2、通过对地理空间认知演进过程的归纳,指出三维地理信息网络服务统一于地理空间认知的历史过程,并将地理空间认知过程用认知操作和认知表达进行了归类。借鉴GIS三层抽象模型,提出了面向三维地理信息网络服务的认知抽象模型,并系统分析了该认知模型两个方面的特征:网络服务空间认知特征和三维地理信息特征。在此基础上提炼了三维地理信息网络服务的三个关键技术。3、从地理空间模型的分类出发,分别以基于域和基于对象的方法研究了适合于三维地理信息网络服务的地形数据和地物模型数据的表达和组织方法。针对地形数据,采用了基于图幅的规则格网分层分块方式和四叉树组织方法;针对地物模型数据,采用了基于CityGML思想的面向对象多层次建模方式,利用二次改进的R树索引对其进行了管理。R树的二次改进包括“与四叉树的结合”和“顾及地物模型LOD层次”。4、分析了面向现有三维地理数据情况下可能的用户需求,并以此为依据确定了不同层次的服务粒度。基于以上的粒度分析,利用WCF服务封装技术,完成了七种三维地理信息服务的设计和实现,包括:基于WFS的地形数据服务、顾及几何融合的地形数据服务、基于WMS的栅格图片服务、基于预生成图片的栅格图片服务、基于WCF通用契约的地物模型数据服务、基于W3DS的三维场景服务和基于WVS的三维视景服务。5、提出了用户角色转换的概念,将网络服务中用户连接和角色转换分为两种模式:串联方式和并联方式。提出了以用户角色并联转换方式来解决海量三维地理信息分发的全新方法。从用户角色并联转换角度出发,提出了用户对等网络的概念,设计了用户节点之间的关联模式,并基于四叉树的资源定位方式实现了海量三维地理信息的分发。6、分析了网络环境下两种常见的结构模式和二维地理信息服务体系架构,从中借鉴经验,探索地理信息网络服务架构的模式特点,然后结合WCF通信技术,通过分析各类服务的客户/服务端的应用逻辑部署,设计了WCF技术支持下包含服务层、中间层和用户层的三维地理信息网络服务体系架构。7、设计了三维地理信息网络服务实验系统。主要从三维地理信息网络服务的效果和性能上设计实验方法,对以上研究内容进行了实验和测试。更多还原

【Abstract】 Three-dimensional (3D) geographic information web service is not only greatly required by geographic information web service extension and application, but also bringing new solution schemes for 3D geographic information share, mutual operation and integration. Therefore, it has great practical values to be studied. According to problems existed in current research status, theories related to 3D geographic information web service were proposed from the point of abstract cognition model understanding, and some key technique problems were extracted and systematically studied. Finally, research contents of this paper were experimented and tested.Main contents of this paper are generalized as follows.From the inevitable development trend of geographic information web service, research meanings of geographic information web service were pointed out. And then, status, current theories and technique fruits of web 2D GIS, geographic information web service and 3D geographic information web service were analyzed. Finally, main contents of this paper were summed up.Through analyzing and summing up of geographic spatial cognition process, it was found that 3D geographic information service was essentially a geographic spatial cognition historical process. Then, the geographic spatial cognition process was classified by cognition operation and cognition expression. Based on three layer GIS abstract model, an abstract cognition model for 3D geographic information web service was proposed. Moreover, two features of the cognition model were systematically analyzed, while one is web service cognition feature and another one is 3D geographic information feature. Finally, three key techniques of 3D geographic information web service were extracted.Beginning at the classification of geographic information model, and based on region and object method, expression and organization methods of terrain data and object model data appropriate for 3D geographic information service were studied. According to terrain data, the mapsheet based regular grid partition methods and quad-tree organization methods were applied, while according to object model data, CityGML idea based and object-oriented multi-layer modeling methods were applied and managed by the improved R tree index. The improvement of R tree included the combination of quad-tree and LOD layer designing of object model.Possible user requirements of 3D geographic information service were analyzed, and the granularity of different service layer was determined. Based on granularity analysis, seven types of 3D geographic information service, including WTF based terrain data service, geometric fusing based terrain data service, WMS based grid image service, image pre-generation based grid image service, WCF general contract based object model data service, W3DS based 3D scene service and WVS based 3D visual scene service, were designed and implemented through WCF service packaging technique.A user role transition concept was proposed, and the user connection and role transition in web service was classified into two modes, while one is sequential mode and another one is parallel mode. By user role parallel transition, a freshly new method was proposed to solve problems of massive 3D geographic information distribution. Then, based on user role parallel transition, the concept of User Equal Web and connection mode between user nodes was designed, and then massive 3D geographic information distribution was implemented by quad-tree resource positioning.Under web service environments, two structure modes and 2D geographic information service structure were analyzed. Related techniques were utilized to explore characteristics of the geographic information web service. Then, combing the WCF communication technique, client & service application logic for each service was analyzed. And supported by WCF technique, a 3D geographic information web service structure, including service layer, middle layer and user layer, was designed.An experimental system for 3D geographic information web service is designed. Meanwhile a series of methods were designed to improve effects and performance of the system, and finally the methods were verified by practical experiments.更多还原