基于小波变换的海洋地磁日变改正研究  

Study of Marine Geomagnetic Diurnal Variation Correction Based on Wavelet Transform

作　　者：张连伟 郑彦鹏 梁瑞才 马龙 李先锋 刘洋廷 华清峰 夏成龙 ZHANG Lian-wei;ZHENG Yan-peng;LIANG Rui-cai;MA Long;LI Xian-feng;LIU Yang-ting;HUA Qing-feng;XIA Cheng-long(First Institute of Oceanography, MNR, Qingdao 266061, China;Laboratory for Marine Geology,Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266061,China)

机构地区：[1]自然资源部第一海洋研究所,山东青岛266061 [2]青岛海洋科学与技术试点国家实验室海洋地质过程与环境功能实验室,山东青岛266061

出　　处：《海洋科学进展》2020年第4期635-648,共14页Advances in Marine Science

基　　金：中国大洋矿产资源研究开发协会项目——大西洋靶区多金属硫化物调查区综合地球物理异常与找矿应用(DY135-S2-2-04);国家自然科学基金委员会-山东省人民政府联合基金项目——海洋地质过程与环境(U1606401);国家自然科学基金青年基金项目——基于柔性边界模型的南海北部陆坡峡谷区海底滑坡运动定量研究(41606084);青岛海洋科学与技术试点国家实验室鳌山科技创新计划——深海资源勘查技术与装备体系发展战略研究(2016ASKJ15-02);新型海底地磁日变站(2015ASKJ03-03-03);泰山学者工程专项经费资助项目(TSPD20161007)。

摘　　要：基于现有地磁日变理论和改正方法,对国际公开地磁静日变数据进行傅里叶变换和一维连续小波变换综合分析,判断大于0.2 Hz频段为磁扰变化场在频域的体现,并利用一维离散小波变换将数据分离,完善了已有的地磁静日变改正方法。根据日变数据特征和一维离散小波分解特性,选定sym8小波作为基本小波对数据进行7尺度分解,将日变数据中长期变化和短期变化与磁扰部分在保证保真度条件下有效分离,并与傅里叶级数分解和低通滤波处理效果作对比验证,结果显示一维离散小波变换处理效果更佳。日变数据中短、长期变化与磁扰两部分数据的有效分离并分别改正可提高海洋地磁测量日变改正质量,降低海洋地磁数据处理过程中误差累积程度,提高了现行日变改正方法的科学性、准确性。Based on the existing geomagnetic diurnal variation theory and correction method,this study comprehensively analyzed the international open geomagnetic diurnal variation data by Fourier transform and one-dimensional continuous wavelet transform,and judged that the frequency band greater than 0.2 Hz is the embodiment of the magnetic disturbance change field in the frequency domain,and used one-dimensional discrete wavelet transform to separate the data,and thus improved the existing geomagnetic diurnal variation correction method.According to the characteristics of daily variation data and one-dimensional discrete wavelet decomposition,this study selected the Sym8 wavelet as the basic wavelet to decompose the data at 7 scales,and the long-term and short-term changes of daily variation data are effectively separated from the magnetic disturbance part under the condition of ensuring the fidelity.Compared to the Fourier series decomposition and low-pass filtering,the processing effect of one-dimensional discrete wavelet transform got better results.The quality of daily variation correction in marine geomagnetic survey can be improved by using the effective separation and correction of short-term,long-term changes and magnetic disturbances in daily variation data,which reduce the error accumulation in the process of marine geomagnetic data processing,and improve the scientificity and accuracy of the current diurnal variation correction methods.

关 键 词：海洋地磁测量 地磁静日变改正 磁扰 小波变换 

分 类 号：P229[天文地球—大地测量学与测量工程]