小区域高精度坐标转换计算方法

Calculation Method of High Accuracy Coordinate Transformation in Small Area

为方便区域施工测量,许多施工企业在小区域内建立了自成体系的坐标系统,但随着测量技术的进步,逐渐需要转化为国家统一坐标,以实现与周围控制点的联网。本文选择了布尔莎四参数、布尔莎七参数、莫洛金斯基模型、仿射六参数模型、多项式逼近模型,以讨论小区域坐标转换时最佳适用的模型;结果表明,布尔莎四参数、布尔莎七参数、莫洛金斯基模型在小区域坐标转换中精度相当,仿射六参数模型优于前三者,多项式逼近模型精度最高,X坐标拟合中误差为4.4 mm,Y坐标拟合中误差为7.4 mm。

In order to facilitate regional construction survey,many construction sites have established their own coordinate systems in small areas,but with the progress of measurement technology,they need to be transformed into national unified coordinates to realize networking with surrounding control points.In this paper,four parameters,seven parameters,Molodensky model,affine six parameter model and polynomial approximation are selected as examples.The results show that the accuracy of four parameters,seven parameters and Molodensky model is equivalent,the affine six parameter model is better than the first three,the polynomial approximation model has the highest accuracy,the mean square error of x-coordinate fitting is 4.4 mm,and the mean square error of y-coordinate fitting is 7.4 mm.