利用大地边值问题方法统一全球高程基准

为解决世界各国高程基准差异的问题,提出联合卫星重力场模型、地面重力数据、GNSS大地高、局部高程基准的正高或正常高,按大地边值问题法确定局部高程基准重力位差的方法。首先推导了利用传统地面"有偏"重力异常确定高程基准重力位差的方法;接着利用改化Stokes核函数削弱"有偏"重力异常的影响,并联合卫星重力场模型和地面"有偏"重力数据,得到独立于任何局部高程基准的重力水准面,以此来确定局部高程基准重力位差;最后利用GNSS+水准数据和重力大地水准面确定了美国高程基准与全球高程基准W₀的重力位差为-4.82±0.05 m²s^-2。

Global Height Datum Unification Using Geodetic Boundary Value Problems Algorithm

In order to unify height datums in different countries,an algorithm based on geodetic boundary value problems (GBVP) is presented,which utilizes satellite gravity field models,terrestrial gravimetric data,GNSS geodetic heights,orthometric heights or normal heights.First of all,the algorithm to determinate height datum geopotential difference using conventional terrestrial "biased" gravity anomalies is deduced.Secondly,the indirect biased term is neglected by using modified Stokes kernel function.A geoid that is not related to any local vertical datums is obtained by combining satellite-only gravity field models and terrestrial "biased" gravity anomalies.That independent geoid is then adapted to determinate height datum geopotential difference.At last,the geopotential difference between US vertical datum (NAVD88) and world geoidal geopotential W₀ is determined through GBVP by combining GNSS/leveling benchmark data and gravity geoid,which is about -4.82±0.05 m²s^-2.