中文摘要：

在没有地面重力数据的情况下,以目前最新公布的V18.1全球1′×1′重力异常作为局部重力数据,分别以360阶EGM96和EGM08作为参考场,同时考虑了加地形改正和不加地形改正两种情况,利用＂移去-恢复＂法计算了研究区多个大地水准面,并探讨了这些大地水准面的精度。结果表明,不同精度地球重力位模型作为参考场所计算得到的重力大地水准面的精度存在一定差异,但是利用高精度GPS水准数据对其进行系统偏差改正后,得到的拟合大地水准面的精度接近,均为0.05 m左右;不加地形改正的拟合大地水准面的精度要略高于加地形改正的精度。利用工程实例数据对拟合大地水准面进行评价时,两者之间存在明显的系统偏差,这主要与工程数据精度高低、工程起算点数据与拟合大地水准面差异的大小有关。

英文摘要：

The recently published V18.1 Global Gravity Anomaly（GGA） is used as the regional gravity data to determine several geoids of the study area with the Remove-Restore technique,in the case of no available terrestrial gravity data.In the computations,the EGM96 and EGM08 up to degree and order of 360 are chosen to be the reference fields respectively and the effects of the terrain undulations are also taken into account.Then,the accuracies of the computed geoids are discussed and the results are shown as follows.The accuracies of the gravimetric geoids derived by two reference fields are different.However,after removing the systematic bias using the Least Square Fitting Method combining the high-accuracy GPS/Leveling data,the gravimetric geoids turn out to be the fitting geoids whose standard deviations are identical,all about 0.05 m.Moreover,the accuracies of the fitting geoids without terrain correction are a little higher than those with terrain correction.