单点和多点法确定区域性椭球空间位置及元素

在工程GPS网的平差转换中 ,为使GPS网与地面网在空间边长投影方面取得相一致的边长尺度 ,须选用一个与地面网边长归算高程基准面 (以下简称为投影面 )尽可能贴近的区域性椭球面 .将现有的各种确定区域性椭球面的方法归结为单点法和多点法 2大类 ,简述了各自的出发点及其具体做法 ,并进行了各方面的分析比较 .从而说明 :按单点法确定的区域性椭球面具有一定的近似性 ;当测区范围较大时 ,更宜采用多点确定法 .

Determination of Element and Space Position of Regional Ellipsoid by Single-point or Many-points

In adjustment and transformation for engineering GPS control networks,we should adopt a regional ellipsoidal surface which is in conformity with the reference level for the reduction of side length(projection surface) in survey area,so that an indentical scale for projecting of space side between GPS and the terrestial network can be achieved.In this paper,current methods for determining regional ellipsoidal surface are summed up in to two kinds,the one by single-point and the another by many-points and teir respective starting points and procedures are introduced briefly.Then these two methods are analyzed and compared.It can be concluded that the regional ellipsoid determined by the single-point -method has certain approximation.If survey region is extended,many-points -method should be adopted.