SUMMARY

In this paper, a new method for regionally improving global geopotential models (GGMs) with global navigation satellite system (GNSS)/levelling data is proposed. In this method, the GNNS/levelling data are at first converted to disturbing potential data with inverse Bruns’ formula. Then the systematic errors in disturbing potential data are removed with a three-parameter correction surface. Afterwards, the disturbing potential data on the Earth's surface are downward continued to the surface of an inner sphere with inverse Poisson's integral equation. Global disturbing potential data on the whole sphere could be achieved with combination of the downward continued data and the GGM-derived data. At last, the final regionally improved geopotential model (RIGM) could be recovered from the disturbing potential data using least-squares method. Four RIGM models for Qingdao (QD) are determined based on four different sets of GNSS/levelling data points to validate the capability of the method. The standard deviation of height anomaly errors of RIGM-QDs are nearly 25 and 30 per cent on average smaller than Earth Gravity Model 2008 (EGM2008) on checkpoints and data points, respectively. This means that the RIGM-QDs fit better to the GNSS/levelling network in this area than EGM2008. The results show that the proposed method is successful at improving GGMs in regional area with regional GNSS/levelling data.

中文翻译：

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一种使用GNSS /水准数据在区域内改进全球地势模型的新方法

概要

本文提出了一种利用全球导航卫星系统（GNSS）/水准仪数据区域改进全球地势模型（GGM）的新方法。在这种方法中，首先使用反布伦斯公式将GNNS /水准数据转换为干扰潜在数据。然后，用三参数校正表面消除干扰电势数据中的系统误差。之后，利用反泊松积分方程，将地球表面的干扰电势数据继续向下延伸到内球表面。向下连续数据和GGM衍生数据的组合可以实现整个领域的全球潜在干扰数据。最后，可以使用最小二乘法从扰动势数据中恢复最终的区域改进的地势模型（RIGM）。根据四套不同的GNSS /水准数据点确定了四个青岛（QD）RIGM模型，以验证该方法的功能。RIGM-QD高度异常的标准偏差在检查点和数据点上分别平均比Earth Gravity Model 2008（EGM2008）小25％和30％。这意味着与EGM2008相比，RIGM-QD在此区域更适合GNSS /水准仪网络。结果表明，所提出的方法成功地利用区域GNSS /水准仪数据改善了区域区域的GGM。RIGM-QD高度异常的标准偏差在检查点和数据点上分别平均比Earth Gravity Model 2008（EGM2008）小25％和30％。这意味着与EGM2008相比，RIGM-QD在此区域更适合GNSS /水准仪网络。结果表明，所提出的方法成功地利用区域GNSS /水准仪数据改善了区域区域的GGM。RIGM-QD高度异常的标准偏差在检查点和数据点上分别平均比Earth Gravity Model 2008（EGM2008）小25％和30％。这意味着与EGM2008相比，RIGM-QD在此区域更适合GNSS /水准仪网络。结果表明，所提出的方法成功地利用区域GNSS /水准仪数据改善了区域区域的GGM。