高精度海岸带重力似大地水准面的若干问题讨论

本文针对海岸带多源重力数据和地形特点，通过理论分析和试算，对若干影响厘米级似大地水准面确定的关键问题进行了剖析，得出一些有益的结论。我国海岸带Molodensky一阶项对高程异常的贡献在10～30cm，需在Molodensky框架中精化重力似大地水准面；精细处理地形影响是提升多源重力场数据处理水平的重要途径；地球外空间不同高度、任意类型重力场参数的地形影响、地形补偿和地形Helmert凝聚算法可以统一；重力场数据处理中大地测量基准不一致的影响会随数据处理算法的不同而变化，在多源重力数据处理时此类影响易变得不可预测和控制；将地形Helmert凝聚理论引入Molodensky框架，可以解决以其他重力场参数（如扰动重力、垂线偏差等）为边界条件的似大地水准面精化问题。

Discussion of Some Issues in the Coastal Precise Quasi-geoid Determination

For the coastal zone, the multi-source gravity data co-exist and terrain features are diversity, through theoretical analysis and a spreadsheet, some issues in quasi-geoid determination with cm-level precision were discussed, and draw some useful conclusions. Taking into account Molodensky first-order contribution to the height anomaly about 10 ~ 30cm in China's coastal region, refined gravity quasi-geoid should be in the Molodensky frame. Fine topographic effect processing is a fundamental way to handle multi-source gravity data. The algorithm for topography effect, mass compensation and helmert condensation for any height, any type gravity field parameters in earth outer space can be unified. The effect of the inconsistent geodetic reference to the gravity data processing vary with the data processing algorithm. in multi-source gravity data processing procedure such influence can be unpredictable. The terrain Helmert condensation can be introduced to Molodensky framework with any type of gravity data