GNSS高程代替五等水准在既有铁路改造工程勘测项目中的应用

全球卫星导航系统实时动态(GNSS-RTK)技术已广泛应用于各工程领域测量中，文中简述了GNSS-RTK技术在铁路改造项目中应用的原理和优点. 利用区域控制网对水准点进行采集，将成果添加到点校正集中进行后校正. 将既有铁路改造项目与水准测量高程成果数据进行对比，得出通过增加一定数量的高程点、参与点进行校正. RTK高程能够达到五等水准高程的精度，在平原或山区地带类似项目应用中具有一定的借鉴意义. 

Application of GNSS elevation instead of the fifth grade leveling elevation in the survey project of existing railway renovation project

Real time dynamics of Global Satellite Navigation System (GNSS-RTK) technology has been widely used in various engineering fields. This article describes the principle and advantages of GNSS-RTK technology in railway reconstruction projects. Regional control network is used to collect leveling points, and the results are added to the point correction concentration for post-correction. By comparing the results of existing railway reconstruction projects with those of leveling survey, it is concluded that RTK elevation can reach the accuracy of the fifth grade leveling elevation by adding a certain number of elevation points to participate in point correction, the similar project application has the certain reference significance in the plain or the mountainous area.