附加GPS时序约束的GRACE陆地水储量反演

发布时间：2018-07-13 12:33

【摘要】：利用GRACE重力卫星反演陆地地球物理变化信息时,通常需要对位系数进行截断和空间平均滤波等处理,这将导致监测信息较实际值"缩减"一定的比例,从而造成反演结果可信度降低.针对此,本文提出了一种附加GPS时序约束的GRACE反演陆地水文信息修正法.利用2003-2015年RL05_GRACE月重力场数据,选取前60阶采用扇形滤波与去相关滤波组合法,获得了加州区域由于陆地水储量及地表荷载变化引起的垂向形变时间序列,并利用同时间段多个GPS测站资料获得了同尺度U方向形变时间序列,采用时频分析技术对比分析了两类垂向形变时间序列的振幅与季节性特征,获取了GRACE位系数处理中存在的"缩减系数",基于此修正并精化了GRACE反演水文变化信息,该信息能有效反映出研究区域较真实的陆地水文变化信息.
[Abstract]:When retrieving the terrestrial geophysical change information by Grace gravity satellite, it is usually necessary to truncate the potential coefficient and to filter the spatial average, which will result in a certain proportion of the monitoring information "reduced" compared with the actual value. As a result, the credibility of the inversion results is reduced. In this paper, a modified method of Grace inversion of land hydrological information with GPS timing constraints is proposed. Based on the monthly gravity field data of RL05GRACE from 2003 to 2015, the vertical deformation time series caused by the changes of land water reserves and surface loads in California region is obtained by using the first 60 orders by using the combination of sector filtering and de-correlation filtering. The U-direction deformation time series of the same scale are obtained by using the data of multiple GPS stations in the same time period. The amplitude and seasonal characteristics of two kinds of vertical deformation time series are compared and analyzed by time-frequency analysis technique. The "reduced coefficient" in Grace bit coefficient processing is obtained, and based on this, the Grace inversion hydrological variation information is refined, which can effectively reflect the real land hydrological variation information in the study area.
【作者单位】：长安大学地质工程与测绘学院;
【基金】：国家自然科学基金(41674001,41604001,41504005,41202189,41207455) 陕西省自然科学基础研究计划资助项目(2016JM4005) 中国博士后基金(2013M530412,2016M602741) 中央高校基本科研业务费专项资金资助项目(310826172202)联合资助
【分类号】：P223;P228.4;P332

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