一种提高不同基准间平面坐标转换精度的方法
A Method to Improve the Accuracy of Plane Coordinate Conversion Between Different Benchmarks
孟凡超1
作者信息
- 1. 中国铁路设计集团有限公司,天津 300251
- 折叠
摘要
为了提高不同基准间平面坐标转换的精度,采用一种求解坐标系近似参数的四参数坐标转换方法,其主要步骤为:首先通过研究高斯投影变形及抵偿坐标系原理,分析投影面大地高与坐标转换控制点间长度变形的线性相关性,再结合高斯投影对角度投影变形的影响,确定需要采用含有尺度参数及旋转参数的坐标转换模型,如四参数、七参数转换模型,以削弱控制点间的线性投影变形差;其次通过分析椭球类型对坐标转换控制点间投影变形差值的影响,采用一种求解不同椭球坐标系近似参数的方法来削弱高斯投影非线性变形差.研究表明,椭球类型对坐标非线性投影变形差的影响为亚毫米级,不同基准间坐标系参数近似一致时,四参数与七参数进行坐标转换的内、外符合精度均达到毫米级.通过工程实例验证,求解坐标系近似参数的四参数坐标转换方法可将坐标转换精度提高一个数量级.
Abstract
In order to improve the precision of plane coordinate conversion between different datum,a four-parameter coordinate conversion method which calculated the approximate parameters of coordinate system first was adopted.The main steps of the method are as follows:Firstly,by studying the Gaussian projection deformation and the principle of compensating coordinate system,the linear correlation between the height of the projection surface and the length deformation of the coordinate transformation control point was analyzed.Then,combined with the influence of Gaussian projection on the angular projection deformation,the coordinate transformation model with scale parameters and rotation parameters was determined to reduce the linear projection deformation difference between control points,such as the four-parameter and seven-parameter transformation model.Secondly,by analyzing the influence of ellipsoid type on the projection deformation difference between coordinate transformation control points,a method which calculating the approximate parameters of different ellipsoid coordinates was proposed to reduce the Gaussian projection nonlinear deformation difference.The research results show that,the effect of ellipsoid type on the nonlinear projection deformation of coordinates is submillimeter.When the coordinate system parameters of different datum are approximately the same,the inner and outer coincidence accuracy of the coordinate transformation of four parameters and seven parameters can reach millimeter level.An engineering example shows that the precision of coordinate transformation can be improved by one order of magnitude by the four-parameter coordinate conversion method which calculates the approximate parameters of coordinate system first.
关键词
铁路/非线性投影变形/四参数/坐标系/近似参数Key words
railway/nonlinear projection deformation/four parameters/coordinate system/approximation parameters引用本文复制引用
出版年
2024
NETL
NSTL
万方数据