Discussion on Availability for Replacement of Leveling Surveying by GPS Elevation Fitting

Plane coordinates of millimeter level accuracy can be got by GPS survey, but precise GPS ellipsoidal height isn’t applied in practice, because of the separation between quasi-geoid and reference ellipsoid. So it’s always a hot topic how to transform GPS ellipsoidal height into level elevation and to keep certain accuracy. Based on the introduction of GPS elevation fitting model, the availability that leveling is replaced with GPS elevation fitting is verified using measured data.