Establishment of GPS 3-dimension Engineering Control Network Using Gravity Quasi-geoid

In order to change the conventional separate mode of plane and height control network, the new method of establishing 3-dimension GPS engineering control network using gravity quasi-geoid was proposed. By computing and analyzing with GPS control network of the Remove South Water to North Engineering, the accuracy of normal heights that were computed using new method was excelled 0.050m. The 3-dimension GPS engineering control network can improve the accuracy of normal heights that are converted from GPS ellipsoid heights and replace low- grade geometrical levelling measure in some civil engineering.