Computational stages of a new high-resolution 5 mm quasigeoid model for Estonia are explained. Certain requirements for the quality and coverage of gravity data in the context of 5 mm geoid modelling were fulfilled. The present gravity data coverage over the target area is 1 point per 10 km², less dense in adjacent land and marine areas. The average uncertainty estimate of gravity data within the target area is about 0.5 … 0.75 mGal. The gravity data were merged, cleaned, analysed, reduced and gridded to yield a seamless gravity anomaly field. A least squares modified Stokes formula (Sjöberg, L.E., 1991. Refined Least Squares Modification of Stokes Formula”. Manuscripta Geodaetica, 16, 367–375.) that combines local terrestrial gravity anomalies and the global geopotential model derived long-wavelength component in a truncated Stokes’s integral yielded the best gravimetric geoid modelling results. The combined uncertainty for most of the Estonian GNSS-levelling points is not exceeding 5 mm, allowing an adequate verification of the geoid modelling quality. Inter-comparison of the geoid model, GNSS-derived and spirit-levelled heights at discrete points was conducted for geoid modelling assessment. A two stage stochastic spatial prediction was applied to obtain an optimal fit between precise GNSS-levelling data and the geoid model. The location-specific post-fitting uncertainties of the resulting model EST-GEOID2017 revealed standard deviation of 4.2 mm, i.e. the same level as the accuracy of the used GNSS-levelling control points.

解释了新的爱沙尼亚高分辨率5毫米拟类星体模型的计算阶段。在5 mm大地水准面建模的背景下，满足了重力数据质量和覆盖率的某些要求。当前目标区域上的重力数据覆盖率为每10 km ² 1个点，在邻近的陆地和海洋区域密度较小。目标区域内重力数据的平均不确定度估计约为0.5…0.75 mGal。对重力数据进行合并，清理，分析，缩小和网格化，以产生无缝的重力异常场。最小二乘修改的斯托克斯公式（Sjöberg，LE，1991年。《改进的最小二乘修改斯托克斯公式》。《地理手册》（16，367–375。）），该方法结合了局部地球重力异常和截断的Stokes积分中的整体地球电势模型得出的长波分量，产生了最佳的重力大地水准面模拟结果。爱沙尼亚大多数GNSS调平点的总不确定度不超过5 mm，从而可以充分验证大地水准面建模质量。对大地水准面模型，GNSS派生的高度和离散点处的水准高度进行了相互比较，以进行大地水准面模型评估。应用两阶段随机空间预测以获得精确GNSS水准数据与大地水准面模型之间的最佳拟合。所得模型EST-GEOID2017的特定于安装后的位置不确定性表明标准偏差为4.2 mm，即