1985国家高程基准与全球似大地水准面之间的系统差及其分布规律

将由大地高和正常高导出的几何高程异常与由位系数模型计算得到的物理高程异常进行比较,求出1985国家高程基准与全球似大地水准面之间的系统差,并分析其分布特性.为抵制异常值的影响,引入"抗差等价权".利用分布全国大陆范围的GPS网949个点的GPS/水准数据和地球重力场模型EGM96、DQM99A,求出1985国家高程基准点与WGS84定义的似大地水准面之间有35.7 cm的垂直偏差,1985国家高程基准面的系统差自东向西、自南向北明显增大,给出相应的数学模型.

The Systematic Difference and Its Distribution between the 1985 National Height Datum and the Global Quasigeoid

The comparison of the height anomaly derived from an ellipsoidal height and a normal height with that from the potential coefficient model is made. The vertical shift between the 1985 National Height Datum and the quasigeoid is calculated. A robust equivalent weight is applied, It controls the significant of outlying observations. The original vertical shift between the 1985 National Height Datum and the quasigeoid defined by WGS84 is calculated.The shift is about 35.7 cm based on a data set of 949 GPS/Leveling points distributed over the country and the Earth gravity field model (e.g. EGM96 and DQM99A). The trend of the systematic difference of the 1985 National Height Datum surface is larger and larger from the east to the west and from the south to the north. The mathematical model is given in this paper.