我国高程基准偏差的确定

Determination of systematic velical deviation of Chinese height datum

我国高程基准偏差包括大地水准面与我国高程基准之间的偏差以及几何正常高与重力正常高之间的偏差。文章首先阐述了我国高程系统中的几何正常高、重力正常高之间的关系;然后从青岛验潮站平均海面重力位、大地水准面重力位以及参考椭球重力位三者的几何关系出发,详细分析了常用的确定我国高程基准与大地水准面偏差的重力位差法和高程异常法这两种方法的内在联系;最后采用青岛及周边的重力数据、地形数据、GNSS水准数据分别计算得到几何正常高与重力正常高的偏差为10.4cm、我国高程基准与大地水准面的偏差为33.3cm。

The systematic vertical deviations of Chinese height datum consist of the deviation of Chinese height datum from the global geight datum and that of the geometric normal height from the gravitational normal height.In this paper,the relation ship between the geometric normal height and the gravitational normal height is represented firstly.Then based on the geometric relationship among the gravitational potentials of the mean sea level of Qingdao tidal station,geoid and the reference ellipsoid,the authors compared and analyzed the internal relation between the gravitational potential difference method and the height anomaly difference method which are generally used to determine Chinese height datum and global height datum.Finally,the gravity data,terrain data and GNSS/level data from Qingdao and surrounding areas are collected.The calculation results show that the deviation of the geometric normal height from the gravitational normal height is 10.4 cm,and the deviation of Chiness height datum from the global height datum is 33.3 cm.