Showing papers by "State Bureau of Surveying and Mapping published in 2003"
TL;DR: In this paper, the authors proposed an extended merge technique to reduce the systematic error in the merge between the geoids of China mainland and China sea, where the two geoids are merged together and the difference, mainly systematic error, between the two kinds of geoids can be usually found.
Abstract: Geoid determination on China Sea via corresponding deflection of the verticals is obtained from satellite altimeter data with the inverse Molodensky formula. In order to examine the accuracy of the geoid, two measures have been applied. Firstly the gravity anomalies are computed by using the same data set of the deflection of the verticals with the inverse Vening Meinesz formula. Then the above gravity anomalies are compared with the actually measured gravity data on the sea for external examination. Secondly, the geoid on the China Sea is also computed by the above gravity anomalies with Stoke formula. The comparison of the two geoids is for internal examination. The mean square error for the external and internal examination is ±9 mGal and ±0.025 mGal, respectively. Geoid on the land is determined by gravity and GPS leveling data, and geoid on the sea is determined mainly by altimeter data. If the two geoids are to be merged together, then the difference, mainly systematic error, between the two kinds of geoid can be usually found. This phenomenon and its main causes are discussed and the so–called extended merge technique is suggested in the paper, especially this technique is suited to those coastal and shallow sea areas with sparse gravity data. The results of the computation with this technique demonstrate that the systematic error has been well reduced in the merge between the geoids of China mainland and China Sea.
4 citations