利用GRACE资料构造大尺度时变重力场统一模型  

Large-scale Time-variable Unified Gravity Field Model Using GRACE Data

作　　者：涂弋 陆洋[1,2] 张子占[1,3] 史红岭[1,4,5] 杜宗亮[1,2] 高春春[1,2] 朱传东[1,2] 

机构地区：[1]中国科学院测量与地球物理研究所大地测量与地球动力学国家重点实验室,湖北武汉430077 [2]中国科学院大学,北京100049 [3]美国得克萨斯大学空间研究中心,美国得克萨斯州奥斯汀78759 [4]地理空间信息工程国家测绘地理信息局重点实验室,北京100830 [5]极地测绘科学国家测绘地理信息局重点实验室,湖北武汉430079

出　　处：《武汉大学学报（信息科学版）》2016年第8期1100-1106,1112,共8页Geomatics and Information Science of Wuhan University

基　　金：国家973计划(2013CB733301);国家自然科学基金(41274025;41174064)~~

摘　　要：基于2003～2012年的GRACE卫星重力资料,采用最小二乘拟合的方法,构建了时变重力场统一模型IGG-TVG2013。该模型以球谐系数的形式表达,在考虑趋势项和周期项等经验参数的基础上,还考虑了加速度项和潮汐模型误差、大地震等因素的影响。将IGG-TVG2013模型与GRACE资料进行了比较分析,在全球92%以上的区域二者符合精度优于±1ugal;利用该模型外推预测了2013年1～6月的重力场变化,结果与GRACE实测数据符合较好。这表明IGG-TVG2013模型不但能较好地描述重力场的连续时空变化,而且具有一定的短期预测能力。We established a large-scale time-variable unified gravity field model IGG-TVG 2 0 1 3basedon GRACE satellite data from 2003 to 2012using the least square method.This model is composed of annual and semi-annual trends and periodic terms,usually of each spherical harmonic coefficient.Besides those empirical parameters,an acceleration term,tidal aliasing error,and large earthquakes are taken into account.Acceleration is a modification to linear trend to detect and express more details in signals.Tidal aliasing error is the residual error in a tide model that must be carefully removed from GRACE solutions;a co-seismic jump in the gravity field may disturb the secular trend.An evaluation of IGG-TVG2013 solutions and corresponding GRACE solutions shows that the RMSE value in 92%of global grids was less than one ugal.Extrapolation results for the first half of 2013 using the IGGTVG2013 model shows this model has good potential in short-term forecasting.We concluded that the IGG-TVG2103 model can effectively describe the time-space variability of gravity field.

关 键 词：GRACE 时变重力场统一模型 最小二乘拟合 球谐系数 加速度 潮汐模型误差 大地震 

分 类 号：P231.5[天文地球—摄影测量与遥感]