A two-dimensional position fix that includes only horizontalcoordinates. It requires a minimum of three visible satellites.
二维定位模式，只有平面的座标。必需至少取得三个卫星的资料。
2
The baseline vectors are solved with software GAMIT and the space coordinates determined with 3-d adjustment model. Horizontalcoordinates are adjusted under different conditions.
基线由GAMIT软件解算，利用空间平差模型进行了三维坐标平差，平面平差则在不同的条件下进行。
3
X coordinates: The X coordinate is a point's horizontal distance from the origin.