基于贝叶斯证据的全球地磁场模型主磁场阶数分析  

Analysis of Global Geomagnetic Main Field Model Order Based on Bayesian Evidence

作　　者：马森 马嘉卉 佟继周 李云龙 MA Sen;MA Jiahui;TONG Jizhou;LI Yunlong(National Space Science Center,Chinese Academy of Sciences,Beijing 100190;University of Chinese Academy of Sciences,Beijing 100049;National Space Science Data Center,Beijing 101407)

机构地区：[1]中国科学院国家空间科学中心,北京100190 [2]中国科学院大学,北京100049 [3]国家空间科学数据中心,北京101407

出　　处：《空间科学学报》2023年第4期600-608,共9页Chinese Journal of Space Science

摘　　要：全球主磁场模型描述了主磁场的时空分布特征。模型的主磁场阶数是构建主磁场模型的关键问题之一。使用贝叶斯推理分析全球主磁场模型,依据贝叶斯证据比较模型阶数,为主磁场的阶数分析提供一种统计依据。利用Swarm卫星磁测数据,估计不同阶数的主磁场模型的证据。结果表明,在1~20的模型阶数中,阶数N=12具有全局最佳证据。参照Jefrrey’s scale的阈值区间,数据对阶数N=12的偏好显著优于其他阶数。实验表明,主磁场阶数的证据推理可用于研究主磁场贡献,结果与14阶球谐函数的功率谱分析相匹配。The global main magnetic field model describes the space-time distribution characteristics of the main magnetic field.The order of the main magnetic field in the model is one of the key issues to build the main magnetic field model.This paper used Bayesian inference to analyze the global geomagnetic main field model and compares model orders based on Bayesian evidence.It provided a statistical perspective for the main field order selection.Using magnetic observations from Swarm satellites,the evidence for different orders of the main field model was estimated.The results show that order N=12 has the global best evidence in model from 1 to 20.Referring to the threshold interval given by Jefrrey’s scale,the data preference for order N=12 is significantly better than other orders.The experiment shows that the evidence reasoning of the main magnetic field order can be used to study the main magnetic field contribution,and the results match the power spectrum analysis of spherical harmonic of order N=14.

关 键 词：地磁场 主磁场模型 贝叶斯证据 模型比较 地磁功率谱 

分 类 号：P353.1[天文地球—空间物理学]