新疆G335公路超长连续纵坡线路抵偿坐标系的建立与实践

Establishment and practice of compensation coordinate system for super long continuous longitudinal slope of G335 road in Xinjiang

投影变形是公路控制网必须考虑的问题,特别是在高海拔、长距离等复杂测区。本文以新疆G335公路为例,对超长连续纵坡线路投影变形进行分析与研究,形成9个带抵偿高程面任意投影分带。该方法综合运用了多种措施和方法,提出了"负高程值"的概念,打破了高程归化投影变形值都是负值的概念,使得综合影响投影变形满足规范限差要求并且尽量缩减投影分带数量,可为类似工程提供参考借鉴使用。

Projection deformation is a problem that must be considered in highway control network,especially in high altitude,long distance and other complex survey areas.Taking G335 road in Xinjiang as an example,this paper analyzes and studies the projection deformation of super long continuous longitudinal slope line,forming 9 arbitrary projection zones with offset elevation plane.In this method,a variety of measures and methods are comprehensively used,and the concept of"negative elevation value"is proposed,which breaks the concept that the projection deformation values of elevation reduction are all negative values,so that the comprehensive impact projection deformation meets the requirements of the specification limit and the number of projection bands is reduced as much as possible,which can provide reference for similar projects.