北部湾经济区陆海统一似大地水准面精化关键技术研究

Research on the key technology of the unified quasi-geoid refinement in the Beibu Gulf Economic Zone

针对北部湾经济区生态文明建设、海洋资源利用和海洋应急救援事件处置等缺乏统一的陆海高程基准等难题,本文首先利用广西北部湾经济区2764项重力数据和8项GNSS水准数据,应用第二类Helmert凝聚法,反演得到广西北部湾海域及沿大陆海岸线向内陆延伸约15 000 km^(2)区域内置信度较高的重力似大地水准面;然后参考重力场选取EIGEN6C4模型,重力似大地水准面对比8项GNSS水准资料,其精度达2.2 cm;最后采用球冠调和分析方法,将2′×2′格网似大地水准面精度提高至1.6 cm,并将陆地高程基准传递到广西北部湾海域及其海岛上,实现该区域陆海高程基准的统一。

In view of the lack of a unified elevation datum of terrestrial and marine for the construction of ecological civilization, the utilization of marine resources and the disposal of marine emergency rescue events in the Guangxi Beibu Gulf Economic Zone, this paper used 2764 gravity data and 8 GNSS/leveling data in Guangxi Beibu Gulf to solve this problem. Firstly, the gravity quasi-geoid in the area covering Guangxi Beibu Gulf sea area and continental coastline extending inland of about 15 000 square kilometers is precisely determined by the Helmert’s second condensation method. Then taking the EIGEN6 C4 earth gravity field model as the reference gravity field, the determined gravity quasi-geoid is compared with the 8 GNSS/leveling data with an accuracy of 2.2 cm. Finally, through spherical cap harmonic analysis, the quasi-geoid accuracy of the 2′×2′ grid is improved to 1.6 cm, and the terrestrial elevation datum is transferred to the Guangxi Beibu Gulf sea area and its islands, so as to realize the unified regional elevation datum of terrestrial and marine.