高海拔地区投影变形处理方法适用性研究

Research and Analysis on the Applicability of Projection Deformation Processing Methods in High Altitude Areas

在高海拔地区工程坐标系统建设中,对高精度GNSS测量投影变形方法的适用性进行理论与实证分析研究。结合云南高海拔地区程海水利联通工程项目实例,对工程测量中投影变形影响因素进行原因分析与公式推导,分析比较投影变形计算方法中投影面与投影中央子午线的不同组合方案。实例研究得出,在高海拔地区项目以测区平均高程为投影面,反算中央子午线,进行任意带中央子午线投影设置,投影变形最小,建立坐标系统效果最佳。

The article made the theoretical and empirical analysis and research on the applicability of high-precision GNSS measurement projection deformation method in the construction of coordinate systems for water conservancy projects in high-altitude areas.It combines the example of the topographic mapping project of the water conservancy interconnection project in high-altitude areas of Yunnan Province to analyze the causes and derive formulas for the influencing factors of projection deformation in engineering measurement.The different combinations of projection surface and projection central meridian in projection deformation calculation methods are analyzed and compared.Empirical calculation research shows that in high-altitude areas,the project takes the average elevation of the measurement area as the projection surface and calculates the central meridian in reverse.It sets up a projection with a central meridian,minimizes projection deformation,and establishes the best coordinate system effect.