第三个定义对象的大小，即椭球半径。
The third defines how big the object is, it is the radius of an ellipsoid.
对有效地球半径的推导方法和应用进行了讨论。
Application of effective earth radius and methods to derive it are discussed.
动态改变大地水准面差距与地球半径的比值，改善了地球形状的三维表达效果；
Dynamic changing the scale of geoid undulations and the radius of the earth, the video mode of the earth figure is improved.
应用推荐