陆海交界区域厘米级精度似大地水准面的确定

Determination of High Precision Quasi-geoid in Boundary of Land and Sea

为了得到我国某陆海交界区厘米级精度的区域(似)大地水准面,利用43个高精度GPS/水准点和1 045个实测重力点数据对EGM96,WDM94和GFZ计算的局部重力(似)大地水准面进行了比较与评价。结果表明,在该测区用移去-恢复法确定重力(似)大地水准面时,EGM96应该是首选参考重力场模型。该测区处在陆海交界处,海域无GPS/水准数据。经比较发现,采用距离倒数加权平均法将该区重力似大地水准面拟合于GPS/水准数据比在大范围使用的多项式法效果更好。采用该方法计算的测区(似)大地水准面精度优于3cm。

In order to get the determination of quasi-geoid at the boundary of land and sea, Quasi-geoid heights derived from these geo-potential models EGM96, WDM94 and GFZ were compared with the help of the 43 GPS/leveling observations and 1 045 observed gravity anomalies respectively. The results showed EGM96 was a preferred geo-potential model for determining the high precision geoid of this area by using remove-restore approach. Since there was no GPS/leveling data on the sea, the approach of distance weighted average was better at interpolating gravimetric geold with GPS/leveling by comparing with the polynomials. The accuracy of quasi-geoid is higher by 3cm in this area.