区域性高程基准的统一

Unification of regional or local height datum

全球或区域性高程基准面的统一始终是大地测量学研究的主要内容之一 ,对于构建“数字区域”和“数字地球”及研究全球或区域性环境变化具有重要的科学意义和现实意义。本文利用全球重力场模型EGM 96和WDM94及GPS水准数据 ,确定了香港主要高程基准面与我国 195 6黄海高程基准面的重力位差。计算结果表明 ,这两个基准面的重力位差为 (8 36 6± 0 76 5 )m2 s-2 ,表明香港主要高程基准面平均低于我国 195 6黄海高程基准面 (0 85 5± 0 0 78)m2 s-2 。

The unification of global and local or regional height datum,is very important to construct “digital region” and “digital earth”,and also to study some global or regional environment changes. Using high precision GPS/leveling data and global earth's gravity field models EGM96 and WDM94,the geo-potential difference between Hong Kong Principal Datum (HKPD) and 1956 yellow sea height datum of China was determined in the paper.The geo-potential difference is (8.366±0.765)m^2s^(-2).It means that the surface of HKPD is averagely (0.855±0.078)m lower than 1956 yellow sea height datum surface of China.This result is very useful to the unification of height datum for these two neighboring regions.