重力场模型及GNSS/水准的区域似大地水准面精化

Refinement of local quasi-geoid based on earth gravity field models and GNSS/leveling

针对现有地球重力场模型综合利用研究较少的情况,该文利用实测全球导航卫星系统/水准数据分析GOCO03S、ITG-GRACE2010S、GO_CONS_GCF_2_DIR_R4、GO_CONS_GCF_2_TIM_R4和EGM2008等地球重力场模型不同谱域位系数对应的高程异常精度,提出对多类重力场模型进行简单谱组合和加权谱组合,并进行精度分析;然后利用这两类组合重力场模型,结合全球导航卫星系统/水准数据对区域似大地水准面的精化展开研究。计算结果表明:在实验区域,与EGM2008模型相比,采用简单谱组合法和加权谱组合法均能提高模型高程异常的精度,标准差最优分别可达0.081m和0.084m,对应精度提高幅度分别为40.9%和38.5%;以多类重力场模型为基础,经简单谱组合法或加权谱组合法得到组合重力场模型,并利用全球导航卫星系统/水准数据进行精化,可获得较高精度的区域似大水准面,精度最优可达0.048m。

There are many kinds of earth gravity field models, but the comprehensive application study are less. In this paper, firstly the accuracy of model height anomaly corresponding to different potential coeffi- cients of the earth gravity field models such as GOCO03S, ITG-GRACE2010S, GO _CONS _GCF 2 DIR _R4, GO_CONS _GCF 2 TIM _R4 and EGM2008 were analyzed by using global navigation satellite system （GNSS）/leveling data sets. Secondly, the combination models made by the simple spectral combination method or weighted spectral combination method with accuracy analysis were proposed. Lastly, research on the refinement of local quasi-geoid was made by using these two kinds of combination model and GNSS/ leveling data. The result showed that： in the test area, comparing with the EGM2008 model, the simple spectral combination model and the weighted spectral combination model could improve the accuracy of model height anomaly, the best accuracy could reach 0. 081 m and 0. 084 m respectively, the improvement were 40.9 % and 38.5 % ; the local quasi-geoid which was constructed with combination model based on earth gravity filed models and GNSS/leveling data could get better performance in the implementation of GNSS height transformation with the best accuracy of 0. 048 m.