贵阳轨道交通L3工程坐标系转换及精度分析

Precision Analysis & Coordinate System Transformation of Rail Transit L3 Project in Guiyang

贵阳轨道交通L3工程全长约43.2 km,南北走向,工程建设区域与既有贵阳城市坐标系中央子午线距离较远,因而在进行高斯坐标转换时存在较大的投影变形量,不能直接满足轨道交通建设要求,需要建立轨道交通独立坐标系统。以贵阳轨道交通L3为实例,针对贵阳城市坐标系统投影变形量进行计算分析,采用严密的七参数坐标转换方法进行转换精度论证,实现城市坐标系统与轨道交通独立坐标系统的相互转换,满足工程设计和施工要求。

Guiyang rail transit L3 project length is about 40.7 km with north-south direction. The construction area is far away from the central meridian of existing Guiyang urban coordinate system, and there is a large projection deformation when making Gaussian coordinate transformation, it cannot directly meet the rail transit construction requirements, an independent coordinate system of rail transit is necessary. Taking Guiyang rail transit L3 as an example, this paper analyzes and calculates the projection deformation of Guiyang urban coordinate system,and uses the strict seven-parameter coordinate transformation method to demonstrate the conversion precision, and realizes the mutual conversion of the urban coordinate system and the independent coordinate system of rail transit to meet the engineering design & construction requirements.