珠海市陆海统一似大地水准面的确定

Determination of quasi-geoid of the unified terrestrial and marine in Zhuhai

针对通常的似大地水准面模型较少涉及海域的情况,该文基于重力数据和地形数据,采用顾及各类地形位及地形引力影响的第二类Helmert凝集法计算了珠海重力似大地水准面;利用高分辨率和高精度的地形数据来恢复大地水准面短波部分,提高了似大地水准面的精度;利用25个高精度全球卫星导航系统水准资料与重力似大地水准面进行了独立比较,其精度为0.012m;然后,采用球冠谐方法,将重力似大地水准面与25个全球卫星导航系统水准数据联合,建立了珠海市海陆统一的似大地水准面模型,其精度为0.008m;最后,利用15个全球卫星导航系统/水准点对似大地水准面模型进行了外部检核,精度为0.010m。

In this paper,the gravity quasi-geoid in Zhuhai was determined by the Helmert＇s second condensation method based on gravity data and topographic data,and the influences of topographic filed and topographic gravity was also taken into account.During the computation,the topographic data with high resolution and high precision was used to recover the short wave of quasi-geoid,so that to improve the accuracy of quasi-geoid.Compared with 25GNSS/leveling points independently,the accuracy of determined gravity quasi-geoid is ±0.012 m.Then the GNSS/leveling quasi-geoid was derived with spherical cap harmonic method by 25GNSS/leveling points,so the unified quasi-geoid of terrestrial and marine in Zhuhai was determined with accuracy of±0.008 m.Finally,15GNSS/leveling points were used to evaluate the quasi-geoid,and the accuracy is better than 0.010 m.