椭球膨胀法在建立带状工程坐标系的应用研究

Applicability Research on Ellipsoid Expansion Method in Establishing Independent Coordinate System of Linear Engineering

针对长距离大型线状工程由于测区跨度广、平均海拔高、高差起伏大等特点导致测区投影变形过大的问题,利用平均曲率半径法、卯酉曲率半径法、平面解析法、广义微分法4种椭球膨胀法的数学模型,在某线状航道整治工程实际项目中进行研究,从4个指标(椭球长半轴、基准点大地坐标、长度投影以及测区端点高斯投影平面坐标)的变化量分析4种椭球膨胀法特点与性质。结果表明椭球膨胀法具有计算方便、数学模型简洁、椭球参数变化量单一等多个特点,基于平均曲率半径法和卯酉曲率半径法进行椭球膨胀不够严密,而平面解析法和广义微分法的椭球膨胀法更适合长距离大型线状工程施工独立坐标系的建立。

In view of the problem that the projection deformation in the survey area is too large due to the characteristics of wide span,high average altitude and large height difference fluctuation of long-distance large-scale linear engineering,we studied four kinds of ellipsoid expansion methods,including average curvature radius method,prime unitary curvature radius method,plane analytical method and generalized differential method.In this paper,we analyzed the characteristics and properties of four kinds of ellipsoid expansion methods from the variation of four indexes(the long half axis of ellipsoid,geodetic coordinate of datum point,length projection,plane coordinate of Gauss projection of end point of survey area).The results show that the ellipsoid expansion method has many characteristics,such as convenient calculation,simple mathematical model and single variation of ellipsoid parameters.The ellipsoid expansion methods based on average curvature radius method and prime unitary curvature radius method are not strict enough,while the ellipsoid expansion methods based on plane analytical method and generalized differential method are more suitable for the establishment of independent coordinate system for long-distance large-scale linear engineering construction.