Until now,the quasi-geoid is the most effective way to solve the conversion between geodetic height and normal height;but the conversion model of quasi-geoid is confidential data ,it can not be used in the surveying produc-tion.According to the characteristics of height anomaly in Changsha area ,the elevation conversion module which uses the block interpolation algorithm is presented in the paper .It can be used by GPS RTK software to solve the real-time con-version from geodetic height of WGS-84 ellipse to normal height .After checking progress ,the precision of the model is better than that in specification whatever precision and accuracy .The problem of real-time elevation conversion is solved in Changsha City .%目前，似大地水准面精化是解决大地高与正常高之间转换的最有效途径；但其转换模型属于机密数据，不能在外业测绘生产中用其进行实时转换。本文针对长沙地区高程异常的变化特点，采用分块插值拟合算法对其进行插值拟合，并编写成高程转换模块；GPS RTK工程软件调用该模块后，即可实现WGS-84椭球大地高到正常高的实时转换；经检核，本模型内、外符合精度均优于规范要求，解决了长沙市实时高程转换问题。
展开▼
