EGM96,WDM94和GPM98CR高阶地球重力场模型表示深圳局部重力场的比较与评价

Evaluation of EGM96,WDM94 and GPM98CR Geo-potential Models for Representing the Local Gravity Field of Shenzhen, China

为计算深圳精密重力大地水准面 ,利用 62个高精度GPS水准点和 4871个实测重力点数据对EGM96,WDM94和GPM98CR全球重力场模型表示深圳局部重力场进行了比较与评价。结果表明 ,由上述 3个重力场模型计算的大地水准面高和重力异常与实测值之间存在明显的系统偏差 ,当采用GPS水准数据尽可能消除系统偏差以后 ,大地水准面高的精度得到显著提高 ,若应用移去 恢复技术确定深圳高精度大地水准面 ,则WDM94应该是首选的参考重力场模型。

Three geo potential models EGM96, WDM94 and GPM98CR are tested for the determination of the Shenzhen gravimetric geoid. Geoid heights and gravity anomalies derived from these geo potential models are compared with the 62 GPS/leveling observations and 4871 observed gravity anomalies respectively. The results show that there exist systematic biases in the geoid heights and gravity anomalies from these three geo potential models compared with those observed. When such systematic biases are removed according to the observed GPS/leveling data, the absolute accuracy of the gravimetric geoid can be improved significantly. Moreover, WDM94 is a preferred geo potential model for determining the high precision geoid of Shenzhen with remove restore approach.