Determination of Quasi-geoid in Mainland China Using Geopotential Model and GPS/Leveling Data
WEI Ziqing, WANG Gang(Xi'an Research Institute of Surveying and Mapping, Xi'an 710054,China)
We have achieved the quasigeoid in mainland China using geopotential model in conjunction with GPS/Leveling data. The method used can be summarized as follows: for each GPS/leveling point, the height anomaly is computed using a geopotential model and compared with the measured value by GPS/leveling, obtaining thus the correction to the computed value. The correction is used to correct the height anomaly of nearby 15′×15′ grids, as calculated by the geopotential model. This method, in essence, is the fitting of the quasigeoid implied by geopotential model to the quasigeoid measured by the GPS/leveling. Over 950 GPS/leveling points distributed over the mainland are utilized with the spacing being about 100 km. The accuracy of such a 15′×15′ quasigeoid is, on the average, better than 0.5 m for the whole mainland, closed to 0.3 m for the east of 105°E, to 0.6 m for the west, and to 0.5 m for the QinghaiTibet plateau.
【CateGory Index】： P228