中文摘要：

提出了一个新的重力场反演方法，该方法利用由星载GPS相位数据直接求得的卫星平均加速度来反演地球重力场，而无需计算卫星的几何轨道。该方法的优点在于无需求解模糊度参数，并且相邻历元间的系统误差可以有效消除。利用CHAMP和GRACE卫星数据反演重力场模型的算例显示，利用该方法相比利用几何轨道反演重力场获得的重力场模型质量可提高20％左右。

英文摘要：

A new gravity field modeling approach is presented. It is based on average satellite accelerations directly derived from onboard GPS phase measurements, i.e. without computing the kinematic orbit as an intermediate product. An advantage of this approach is that no ambiguity resolution is needed, and most of systematic errors that exist at neighboring epochs can be eliminated. GPS data from CHAMP and GRACE satellites covering 101--day interval were processed to recover a model of Earth＇s gravity field model. The results showed that calculating accelerations directly from GPS measurements improves the quality of the gravity field model by approximately 20%.