在引入Slepian局部谱分析方法的基础上,详细分析Slepian函数的数学特性,采用GrOnbaum算子提高Slepian方法求解的稳定性和效率,推导卫星重力梯度数据确定地球重力场的Slepian方法表达式。通过仿真分析,就Slepian方法在卫星重力梯度数据确定地球重力位模型中的应用和前景进行分析和讨论。研究表明,Slepian函数在整个球面和球带上具有双正交性,其频谱能量分布特性与卫星轨道的测量特点具有很好的一致性。Slepian低次项系数精度受到极空白影响很小,较之球谐系数低次项明显改善。Slepian方法对大地水准面空间分布恢复精度的直接贡献不明显。
The Slepian localized spectral analysis method is introduced and its mathematical characteristics are analyzed. GrQnbaum operator is introduced to improve the computational efficiency and stability. Then, the formulas of Slepian method for recovering the gravity field with satellite gravity gradiometry data are educed and numerical analysis are done. The results show that, Slepian function isorthogonal in both the sphere and the belt, and its spectral energy distribution characteristic is in accord with the orbit characteristic. Also, the accuracy of low order coefficients in Slepian domain is less influenced by polar gaps than that in spherical harmonic domain. However, the direct contribution of Slepian method to the improvement of geoid is limited.