中文摘要：

研究目的：基于数字地球建立铁路三维空间选线平台。研究结论：系统充分利用了数字地球软件提供的数字地形及高清影像等基础地理信息资源，建立了三维空间选线平台，并在“安康至张家界”、“郑州至万州”等项目中成功应用，应用表明该系统具有以下特点：（1）实现了从Google Earth中的实时批量提取数字地形与影像数据；（2）利用Google Earth的KML技术实现在Google Earth进行铁路平面定线．使Google Earth成为铁路的三维空间选线平台；（3）建立了一个铁路线路及沿线自然环境的属性信息录入和查询机制；（4）在传统AutoCAD平台下构建了新建铁路线路平、纵、横设计模块，满足铁路线路精细设计阶段的的各种功能，重点解决了纵断面优化问题；（5）实现了铁路设计成果在Google Earth中的三维可视化.

英文摘要：

Research purposes： The purposes are to establish a digital earth -based three -dimensional spatial platform for railway route selection. Research conclusions：The system make full use of the terrain and high - definition digital images and other basic geographic information resources provided by the Digital Earth Software to establish a three - dimensional alignment platform and it has been successfully applied in many projects, such as Ankang- Zhangjiajie and Zhengzhou -Wanzhou railways. The applications show that the system has following features ： （ 1 ） The real - time digital terrain and image data are picked up from Google Earth. （2） The planar alignment is realized in Google Earth with KML technology of Google Earth, which Google Earth becoming a digital earth -based three -dimensional spatial platform for railway route selection. （3） A logging and query system is established for the information on the railways and natural environment along the railway. （4） The plane, vertical section, cross - sectional design models for a new railway line are established under the traditional AutoCAD platform, which can meet various diamonds of the fine design railway to overcome the problem of optimization of vertical section. （5） The three - dimensional visualization of railway design outcome is realized in Google Earth platform.