The height obtained through the GNSS method is the ellipsoidal height and to have an efficient application in surveying it has to be converted into orthometric height. This paper aims to determine a local geoid model for a part of Duhok region based on the known orthometric height using GPS/levelling and assessing the precision performance of the two Earth gravitational models (EGM1996 and EGM2008) in the study area. The EGMs were adjusted based on root mean square errors, calculated from the differences between two geoid heights, GPS/levelling and EGMs. The Kriging interpolation method was used for creating a local geoid model based on GPS/levelling. The result from the adjusted geoid models to the survey data at 54 points revealed that the mean accuracy of geoidal heights at 0.08 m level is attainable. The precision performance of EGM96 is more precise than EGM08 by 14 mm in the area of interest.

通过 GNSS 方法获得的高度是椭球高度，为了在测量中有效应用，必须将其转换为正高。本文旨在基于已知的正高使用 GPS/水准仪确定 Duhok 地区部分地区的局部大地水准面模型，并评估研究区域内两个地球引力模型（EGM1996 和 EGM2008）的精度性能。EGM 根据均方根误差进行调整，根据两个大地水准面高度、GPS/水准测量和 EGM 之间的差异计算得出。克里金插值方法用于创建基于 GPS/水准测量的局部大地水准面模型。调整大地水准面模型对54点测量数据的结果表明，大地水准面高度在0.08 m水平的平均精度是可以达到的。