An implementation of the Open Geospatial Consortium Web Feature Service (WFS) and Web Map Service (WMS) specifications in an open source desktop GIS is presented together with a discussion of considerations for improv...An implementation of the Open Geospatial Consortium Web Feature Service (WFS) and Web Map Service (WMS) specifications in an open source desktop GIS is presented together with a discussion of considerations for improving the use of web services data in desktop applications. In our implementation, WFS and WMS services are consumed by a plug-in to MapWindow GIS [1], allowing the end user to view WFS, WMS and ArcIMS data, including data from the ESRI Geography Network, in a transparent manner that can be configured for either data analysis and modeling, or data visualization. This implementation in an open source GIS allows for others to view and use the code, improve it, and otherwise implement the suggested considerations in other GIS platforms. Specific considerations proposed here include: pre-fetching through envelope optimization, tile display, and feature complexity reduction. These strategies improve the speed and responsiveness with which data can be viewed and analyzed. Comparisons made with other web-based data access implementations are used to evaluate whether these techniques provide performance benefits, and under which circumstances.展开更多
World Wind是NASA发布的开放源码的地理软件,是提供丰富数据的数字地球平台之一。但是,如何在其已发布数据基础上,通过网络应用来扩展其数据应用,如何将用户的应用数据或其它数据提供者的数据与现有数据结合使用,是我们需要解决的问题...World Wind是NASA发布的开放源码的地理软件,是提供丰富数据的数字地球平台之一。但是,如何在其已发布数据基础上,通过网络应用来扩展其数据应用,如何将用户的应用数据或其它数据提供者的数据与现有数据结合使用,是我们需要解决的问题。通过采用WebService技术进行地理信息服务和发布,使用GeoServer作为地图服务器,将OpenGIS Webservice规范和PostGIS空间数据库进行整合,通过网络空间数据扩展使WorldWind客户端与其自身的数据服务集成使用。在其平台基础上基本实现可自由扩展和发布数据供WorldWind客户端使用,实现更广泛和深入的扩展应用。展开更多
文摘An implementation of the Open Geospatial Consortium Web Feature Service (WFS) and Web Map Service (WMS) specifications in an open source desktop GIS is presented together with a discussion of considerations for improving the use of web services data in desktop applications. In our implementation, WFS and WMS services are consumed by a plug-in to MapWindow GIS [1], allowing the end user to view WFS, WMS and ArcIMS data, including data from the ESRI Geography Network, in a transparent manner that can be configured for either data analysis and modeling, or data visualization. This implementation in an open source GIS allows for others to view and use the code, improve it, and otherwise implement the suggested considerations in other GIS platforms. Specific considerations proposed here include: pre-fetching through envelope optimization, tile display, and feature complexity reduction. These strategies improve the speed and responsiveness with which data can be viewed and analyzed. Comparisons made with other web-based data access implementations are used to evaluate whether these techniques provide performance benefits, and under which circumstances.
基金国家自然科学基金(the National Natural Science Foundation of China under Grant No.40501059)湖北省自然科学基金创新群体项目(the Hubei Science Foundation under Grant No.2006ABC010)
