GNSS RTK高程拟合控制点选取工具设计与实现

Design and Realization of Control Points Selection Tool for GNSS RTK Height Fitting

为解决GNSS RTK测量高程拟合控制点选取难题,以"小范围作业区内采用平面函数模型进行高程拟合"为原则、"地理学第一定律"为依据,提出一种利用控制点空间位置关系、高程异常值、高程不符值和东北斜坡值为参考依据的控制点选取方法。首先,对高程拟合平面函数模型原理进行详细介绍,分析其计算过程;然后,设计GNSS RTK高程拟合控制点选取工具,导入控制点数据并进行计算,得到高程异常值、高程不符值、东北斜坡值等,并以列表和图形曲线的形式直观展现,便于判断和分析,可快速确定用于GNSS RTK高程拟合所需要的控制点;最后,以西南山区某铁路项目为例,对其使用效果进行验证。研究表明,参与高程拟合的控制点高程不符值小于0.1 m、东北斜坡值合理,满足GNSS RTK测量精度要求。

Selecting appropriate control points for height fitting has a crucial influence on its fitting accuracy when performing GNSS RTK surveys in the engineering survey stage.Aiming at the difficulty of selecting control points,the principle of“using plane function model for height fitting in a small working area”and“the first law of geography”is adopted,and the spatial position relationship of control points,elevation abnormal value,elevation discrepancy value and north and east slope value are the reference basis for the selection of control points.The developed software tool can achieve rapid and reasonable selection of control points.This article first introduced the principle of the elevation fitting plane function model in details and analyzed its calculation process;then designed and implemented the GNSS RTK elevation fitting control point selection tool,which could import control point data and perform calculations to obtain elevation abnormal values and elevation Inconsistent values,north and east slope values,etc.The method visually displayed in the form of lists and graphical curves,which were convenient for users to judge and analyze,and could quickly and reasonably determine the control points needed for GNSS RTK elevation fitting;finally,a certain southwest mountainous area railway project was adopted as an example to illustrate the selection process.Practices have shown that the selection method of control points using the spatial position relationship of control points,elevation abnormal values,elevation discrepancies and north and east slope values is reasonable;The control points participating in the elevation fitting have an elevation discrepancy value of less than 0.1 m,and the north and east slope value is reasonable,which can meet the GNSS RTK measurement accuracy requirements;the developed tool greatly improves the efficiency of control point selection and the quality of elevation fitting data.