利用卫星重力数据确定地球外部重力场的一种方法及模拟实验检验

An Approach for Determining the Earth's External Gravity Field by Using Satellite Gravity Data and the Simulation Experiment

  • 摘要: 假定给定了海量的卫星重力观测数据,基于球谐展开法并应用最小二乘原理可以确定地球重力场模型EGM,由此确定的重力场模型在地球表面附近的空间区域未必有效。设想有一个包含了地球的大球KS,假定EGM在大球的外部成立,则可根据虚拟压缩恢复法求出一种新的重力场模型NEGM,它是对原有重力场模型的进一步精化,适合于整个地球外部空间,从理论上可以解决重力场的“向下延拓”问题。初步的模拟实验检验支持虚拟压缩恢复法以及由此而引申出的“向下延拓”法。

     

    Abstract: Giving a large amount of satellite gravity data,based on spherical harmonic expansion and least-squares estimate principle,an earth's gravity field model EGM could be established,which might not be valid in the region near the earth's surface.Choosing a sphere K_S which includes the whole earth,under the assumption that EGM holds correct in the region outside the sphere K_S,and based on the "fictitious compress recovery" approach,it could be established a new gravity model,properly called NEGM,which is valid in the whole region outside Earth,solving the "downward continuation" problem.A preliminary simulation experiment supports the "fictitious compress recovery" approach and the "downward continuation" approach is given in this paper.

     

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