The geoid is used to be regarded as the theoretic global vertical reference . the actual national height references are regional mean sea levels determined by tide gauge station . the difference between them is apparent 大地水准面作为全球高程测量的理论基准面，在现实工作中，国家或者地区高程系统的起算面是利用验潮方法来确定局部平均海平面的，两者之间的差距是显而易见的。
This paper analyzes the principle , error sources and precision of triangulated height surveying , points out the key problems about first order leveling replaced by triangulated height surveying ; and for the first time puts forward that in some given conditions , it is not only feasible but also valuable to replace first order leveling by precise triangulated height surveying , and proves it by experimentation as well 摘要通过对三角高程测量的原理、误差来源及精度分析，指出了用三角高程测量代替一等水准的关键问题，第一次提出了在特定条件下用三角高程测量代替一等水准是完全可行的，并在生产实践中得到了验证。
The surface deformation monitoring of the side - wall by combination of the forward intersection method with the analytical trigonometric elevation measurement demonstrates that the plane deformation and vertical deformation of the side - wall are small , and the quality of dam filling and side - wall construction is satisfactory 用能够满足精度要求的前方交会法与解析三角高程测量法结合的方法对边墙表面变形进行监测，结果表明，边墙平面位移和垂直位移均较小，大坝填筑和边墙施工质量可靠。
