摘要
本文根据地球引力位的球谐函数展开式,利用重力梯度张量各分量导出了位系数模型的精度估计公式.从三方面进行了研究:假定卫星重力梯度仪测量精度,探讨用重力梯度数据确定地球重力场模型的精度;求出位系数模型和大气阻力引起的重力梯度卫星的轨道误差;最后,反求轨道误差和位系数误差对重力梯度测量值的影响.数值计算表明,与地面技术和常规卫星方法相比,卫星梯度测量可使重力场模型的精度至少提高3—5倍;利用重力梯度张量全分量求得的重力值精度比单用径向分量V_(rr)的结果提高40％以上;若仅顾及位系数模型和大气阻力误差,则轨道误差对梯度测量值的影响△V_(i3)(i=3,2,1)至少可分别在1/4和1/3弧圈内达到△V_(i3)≤σ(仪器精度).
According to the spherical harmonics expansion of the Earth's gravitational potential in this paper, the accuracy estimation formulas of the potential coefficient model are derived by the components of gravity gradient tensor. In three different aspects the investigations have been carried out: Assuming the measured accuracy of satellite gradiometer, we make an approach to the accuracies of the Earth's gravity field model determined by the gravity gradient data; The orbital errors due to the potential coefficient model and atmospheric drag for the gradiometry satellite are obtained; Finally, the influence of orbital errors and potential coefficient errors on the gravity gradient measurements are conversely found out. The numerical computations show that the satellite gravity gradiometry can increase the accuracies of gravity field model by 3-5 times at least in comparison with the ground technique and conventional satellite methods; The accuracy of gravity quantities obtained by all components of gravity gradient tensor will make an improvement of more than 40% on that of the only radial component Vrr. If the errors in potential coefficient model and in atmospheric drag are only considered, the influences ΔVi3 (i = 3,2,1) of the orbital errors on gradiometer measurements can satisfy ΔVi3≤σ at least in the 1/4, 1/3 circle of influence respectively.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
1993年第6期725-739,共15页
Chinese Journal of Geophysics
基金
国家自然科学基金
中国科学院资助的课题
关键词
卫星重力学
重力梯度
地球重力场
Satellite gravity gradiometry, Gravity gradient tensor, Potential coefficient, Orbital error, Atmospheric drag.
