基于卫星重力的地球重力场时变模型研究

项目名称： 基于卫星重力的地球重力场时变模型研究

项目编号： No.40874037

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 武器工业

项目作者： 陆洋

作者单位： 中国科学院测量与地球物理研究所

项目金额： 44万元

中文摘要： 项目围绕地球时变重力场的研究主题，在传统的重力场模型理论基础上，提出了"地球重力场时变模型"的新概念，建立了基于空间频域的全球重力场时变模型的基础理论。针对GRACE轨迹条纹误差问题，提出了GRACE卫星重力资料有效信号提取的扇形滤波（Fanfilter）新方法。针对GRACE时变重力场不同资料来源的差异问题，创造性地提出了干涉同化的新概念和多通道维纳滤波实现方案。针对不同空间分辨率的时变重力场资源，研究了时变重力场信息与模型的同化处理方法，为今后融合更多的时变重力场信息（空间与地面），进一步提高重力场时变模型的空间分辨率的研究奠定了基础。利用卫星技术确定的重力场时变信息，分析得到了全球重力场参量以及南极冰盖质量变化趋势。研究分析了地球重力场时变特征和频谱结构，提出重力场时变模型的表示方式和建模方法，开发相应的计算软件，并以GRACE卫星重力为实施对象，建立了能够描述地球重力场在不同观测历元的空间变化的重力场时变数值模型（大尺度），使当前重力场时变信息的应用提升到理论高度，有效提高对相关地球物理现象的描述和深层次的研究模拟，对研究真实地球重力场的数学物理结构、探究揭示其动态有重要意义.

中文关键词： 地球重力场；卫星重力；时变模型；建模方法；球谐函数

英文摘要： The project proposed a new concept of time-varying Earth's gravity field model, and established the basic theory of time-variable gravity field model on the basis of the spatial frequency domain. Aiming at the banding error of GRACE track, a new method, Fanfilter, is proposed for extract the effective signal from GRACE satellite gravity data. In addition, aiming at the difference of GRACE time-variable gravity field due to different data sources, a new concept which is called interference assimilation is creatively proposed and a multichannel Winner filter scheme is designed to carry out this idea. According to the different spatial resolution of time-variable gravity resource, a data assimilation theory of time-variable gravity field information and model is studied, the theory lays a foundation for the further development on combine more time-variable gravity information(ground and space) and improve the spatial resolution of time-variable gravity field model. Besides, using the time-variable information of gravity field is determined by satellite technology, the parameter of global gravity field and the quality changing trend of the Antarctic ice sheet are obtained. Finally, the time-variable characteristic and spectrum structure of earth gravity field are studied and analyzed, the representation and modeling methods of time-variable gravity field model are introduced, and the corresponding calculation software is developed. Meanwhile, choosing GRACE gravity satellite as the research object, the time-variable gravity field numerical models (large scale) are built. These numerical models can not only describe the spatial variation of earth gravity field in different observational epoch, but also promote the application of time-variable gravity field information to theory level, and improve the description and deep-level simulation of related geophysical phenomena effectively. What's more, these models will make important contribution to studying the math-physic structure and dynamic characteristics of real earth gravity field, exploring the theoretical foundation and guiding further research and application.

英文关键词： Earth gravity field; satellite gravity; time-varying model; modeling method; spherical harmonic function