水下极低频电磁信号探测中的海流感应电磁噪声压制  

Current Induced Electromagnetic Noise Suppression in Underwater Extremely Low Frequency Electromagnetic Signal Detection

作　　者：孙公毅 裴建新[1,2,3] 陈家林 张学庆[5] Sun Gongyi;Pei Jianxin;Chen Jialin;Zhang Xueqing(College of Marine Geosciences, Ocean University of China, Qingdao 266100, China;The Key Laboratory of Submarine Geosciences and Prospecting Techniques, Ministry of Education, Ocean University of China, Qingdao 266100, China;Laboratory for Marine Mineral Resources, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266237, China;College of Engineering, Ocean University of China, Qingdao 266100, China;College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China)

机构地区：[1]中国海洋大学海洋地球科学学院,山东青岛266100 [2]中国海洋大学海底科学与探测技术教育部重点实验室,山东青岛266100 [3]青岛海洋科学与技术试点国家实验室海洋矿产资源评价与探测技术功能实验室,山东青岛266237 [4]中国海洋大学工程学院,山东青岛266100 [5]中国海洋大学环境科学与工程学院,山东青岛266100

出　　处：《中国海洋大学学报（自然科学版）》2021年第12期72-80,共9页Periodical of Ocean University of China

基　　金：国家自然科学基金面上项目(41974085);国家重点研究发展计划项目(2019YFC1408100)资助。

摘　　要：水下极低频电磁信号探测在深远海探测领域应用前景广阔,然而极低频电磁信号易受海流运动感应电磁噪声影响,为了拓展极低频电磁探测在海洋中的应用,需要通过信号处理的方式压制噪声,提高信号信噪比。小波分析具有多分辨率分析及时频局部化的优势,适于处理海水运动感应电磁噪声等非平稳信号,本文将海流感应电磁场特征引入小波分析中,基于正演模拟及小波系数分析确定阈值的小波阈值去噪方法压制噪声,利用合成的包含大地电磁信号、海流感应电磁噪声的极低频信号进行实验,并利用南黄海海域电磁信号探测试验数据进行验证。研究结果表明,噪声压制后的极低频信号信噪比明显提高,信号在时频域识别能力得到改善。Underwater extremely low frequency(ELF)electromagnetic signal detection has broad application prospects in the deep sea exploration filed.However,the signal is easily affected by electromagnetic noise induced by ocean current movement.It is necessary to suppress noise and improve signal-to-noise ratio by signal processing in order to expand the application of extremely low frequency electromagnetic detection method.Wavelet analysis has the advantages of multi-resolution analysis and time-frequency localization,which is suitable for processing non-stationary signals such as electromagnetic noise induced by sea water motion.In this paper,the characteristics of ocean current induced electromagnetic field are introduced into wavelet analysis,and the wavelet threshold denoising method based on forward modeling and wavelet coefficient analysis is used to suppress the noise.The experiment is carried out by using the synthesized extremely low frequency signal including magnetotelluric signal and current induced electromagnetic noise,and verified by the electromagnetic signal detection data in the South Yellow Sea.The results show that the signal-to-noise ratio of the noise suppressed ELF signal is significantly improved,and the signal recognition ability in time-frequency domain is also improved.

关 键 词：水下极低频电磁信号 海流感应电磁场 噪声压制 小波阈值去噪 

分 类 号：P631.325[天文地球—地质矿产勘探]