广域监控系统中WebGIS子系统的设计与研究

【作者】 王霞；

【导师】 朱岩；

【作者基本信息】 南京理工大学 ， 控制理论与控制工程， 2009， 硕士

【摘要】 传统C/S结构的监控系统已经不能满足广域分布的被控对象的监控要求,广域监控系统随之产生,并且广泛应用于社会生活的各个领域。而作为广域监控系统信息展示平台的WebGIS,结合地理元素,将对象信息直观、形象地展示出来,已经成为广域监控系统不可缺少的一部分。因此,本文以车辆监控系统为背景,研究WebGIS系统,具有十分重要的现实意义。本文首先根据车辆监控系统的要求设计了WebGIS子系统的三层结构框架,并对每层的各个模块进行了研究分析;其次,通过对空间数据存储方式的比较,选择了PostgreSQL+PostGIS扩展关系型数据库存储空间数据,并对数据进行了入库前的预处理;对地图采用平滑切换的方法,有效解决了地图显示的连续性与平滑过渡的问题。针对车辆监控系统的数据查询,重新设计了空间数据表的结构,并自定义了PostgreSQL函数,解决了某些特殊查询问题,提高了查询的速度;运用ASP.NET AJAX技术对SharpMap进行了重新设计与改写,改变了地图引擎信息表现层的响应形式,解决了信息表现层依赖于地图对象的问题,使信息表现层可以独立请求与刷新,加快了信息表现层的响应速度,提高了系统的性能。最后,本文详细阐述了WebGIS系统中表现层的Ajax应用设计、应用逻辑层中信息表现层的响应过程和信息展示形式以及地图平滑切换的边界查询设计;同时,为提高系统性能提出了一系列的优化策略。更多还原

【Abstract】 The structure of traditional C/S monitoring system can not meet the requirements of monitoring of the wide distributing objects, the wide-area monitoring system is invented and used in the various fields of social life widely. As the information platform of wide-area monitoring system, WebGIS is used to display the information of objects directly and intuitively, combining with the geographical elements. It has been becoming the indispensable part of the wide-area monitoring system. The system of WebGIS is studied in the background of vehicle monitoring system, which has a very important practical significance.First, according to the requirements of the vehicle monitoring system, the three-layer structure of the subsystem of WebGIS is designed and each of the various modules is studied and analyzed respectively . Second, the extended relational database PostgreSQL+PostGIS is chosen to store spatial data by comparison of spatial data storage, the data is processed before imported into spatial database. The method of smooth handoff is used to solve the issue of continuity and smooth transition happened when displaying the map.The structure of the spatial database is redesigned and the PostgreSQL function is defined to solve the issue of the special query and speed up the speed of the data query. The SharpMap map engine is redesigned and rewritten with ASP.NET AJAX technology to change the response form of the presentation layer of information and resolve the issue which the presentation layer of information depends on the map object , the presentation layer of information is requested and refreshed independently ,which speed up the rsponse speed of the system, enhance the performance of the system.In the end, the design of Ajax application in the presentation layer, the response process of the presentation layer of information and the displaying forms of information in the application logic layer as well as the design of boundary data query of smooth handoff are described in detail ;At the same time , a series of optimization strategies are put forward to improve the performance of the system.更多还原