贝叶斯算法在拟合自由核章动参数中的应用  

The application of Bayesian method in determination of free core nutation parameters

作　　者：崔小明[1,2] 孙和平 S Rosat 徐建桥[1] 周江存[1] 陈晓东[1] 

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 [2]中国科学院大学 [3]Institut de Physique du Globe de Strasbourg,Strasbourg 67084

出　　处：《地球物理学报》2013年第1期53-59,共7页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(41021003;41074053和41274085);中国科学院创新团队国际合作计划(KZZD-EW-TZ-05)联合资助

摘　　要：用高精度重力技术检测地球自由核章动(FCN)参数(包括周期和Q值等)的难点是资料观测信噪比低,传统的方法是使用最小二乘拟合,但是获得的FCN共振参数精度不理想.本文利用武汉国际潮汐基准站高精度超导重力仪和全球超导重力仪观测的时变重力资料,根据贝叶斯算法拟合地球自由核章动(FCN)参数.我们将贝叶斯拟合方法与传统最小二乘法实施了对比分析,研究了不同台站资料差异.讨论了潮波选择和不同海潮模型等因素对FCN参数的影响.结果表明用贝叶斯算法获得的FCN品质因子与空间大地测量VLBI结果吻合的更好,这说明贝叶斯算法可靠性高,为研究地球深内部构造参数(核幔边界粘滞系数等)提供了有效依据.The difficulty in the determination of Free Core Nutation （FCN） parameters （period and quality factor） using high precision gravity technique is due to the low signal-to-noise ratio of observations, which affects the determination precision when using traditional least square method. In this paper, we use Bayesian method to fitting the FCN parameters with the help of gravity data observed by superconducting gravimeters in Wuhan and Global stations. The difference using observations from different stations is investigated by comparing the Bayesian method and least square method. We also discussed the influence on FCN determination of choosing different tidal wave and ocean tidal models. The results indicate that Bayesian method is more credible and the FCN quality factor obtained by Bayesian method has a better agreement with that from VLBI observations, which could offer effective reference for further studies of the deep interior of the Earth.

关 键 词：贝叶斯算法 自由核章动 超导重力仪 

分 类 号：P223[天文地球—大地测量学与测量工程] P312[天文地球—测绘科学与技术]