顾及完全球面布格异常梯度项改正的我国似大地水准面精化

Quasi -Geoid Refining of China considering Corrections of Complete Spherical Bouger Anomaly＇ s Gradient Term

本文利用我国1’×1’地形数据，顾及完全球面布格异常梯度一次改正项精化我国似大地水准面，全国范围内的精度在0．5m以内，东部的精度在0．3m以内，西部地区的精度大约0．6m。经过GPS／水准控制后，我国的似大地水准面精度有了明显的改善。同时计算了完全球面布格异常梯度一次改正项对似大地水准面的影响，我国大部分地区为几个厘米，东部地区约0～5cm，西部地区约0—10cm，而西南边境的影响则达到分米级。这说明它对于高程异常的影响能够达到厘米量级，考虑该项影响可有效提高似大地水准面精度。

Considering the first order correction of complete spherical Bouguer anomaly＇ s gradient term, the quasi - geoid of China is refined based on 1＇×1＇ terrain data. The quasi - geoid accuracy of the country is better than 0.5m, of the eastern region is less than 0.3m, and of the western region is about 0.6m. The quasi - geoid accuracy is improved greatly after using GPS/lev- cling data. The effect of the first order correction of complete spherical Bouguer anomaly ＇ s gradient term on quasi - geoid is about several centimeters level in most part of our country, about 0 - 5cm in the eastern and 0 - 10cm in the western region. However, in the southwest border area, it can reach decimeter level, which shows that the effect of complete spherical Bouguer anomaly~ gradient term on height anomaly can reach centimeter level, and the accuracy of quasi - geoid can be improved effectively when taking into account the effect of complete spherical Bouguer anomaly＇ s gradient tenn.