利用卫星重力梯度与地面数据确定地球重力场的分析

本文利用简捷的球谐分析方法讨论了重力场元在地面和空间的谱分布特征和向下延拓问题,分析了各类测量数据求定重力场的最高分辨率及精度。结果表明,在一个低轨道卫星上以适当的精度(优于10~(-2)E)的重力梯度测量可以获得空间分辨率为100公里、精度高于5mgal和10cm的重力场和大地水准面。

Some Analyses of the Determination of the Earth's Gravity Field from the Satellite Gravity Gradient and Terrestrial Data

A rapid and economical way to improve our current knowledge of the global earth gravity field is with aid of space techniques. The satellite gravity gradiometry is a progect to be put in practice in the near future abroad and under studied actively at home. This paper primaryly discusses the spectrum distribution feature of the elements of the gravity field on the surface and at altitude and the downward. continuation problems, and analyzes the possibly availoble hights resolution and accurace of the gravity field determined using different kind of data. The results show that with the gravity gradient measured by a gradiometer on board a low orbiting spacecraft with properly measurement precision (10~(-2)E or better) one can determine the global gravity field and the geoid to better than 5 mgal and 10cm vespectively at a 100 km resolution.