借助于一个区域性辅助椭球将ＧＰＳ网的三维坐标，转换到原有的城市控制网坐标系中．避免了通常采用的具有不确定性的多点重合的转换方法，并且不再以国家大地坐标系的参考椭球上的大地坐标作为过渡，而是以一个辅助椭球上的大地坐标作为过渡．使得ＧＰＳ测点的精度与城市网的精度相一致 With the aid of a regional auxiliary ellipsoid, the three-dimensional coordinates of the GPS network are transformed into the original city control network coordinate system. It avoids the commonly used method of multi-point coincidence with uncertainty, and no longer uses the geodetic coordinates on the reference ellipsoid of the national geodetic coordinate system as the transition, but uses the geodetic coordinates on an auxiliary ellipsoid as the transition. Makes the accuracy of GPS measurement points consistent with the accuracy of the city network