基于小波理论的地磁脉动信号的消噪处理

基于小波理论的地磁脉动信号的消噪处理 Geomagnetic Micro Pulsation Signal’s De-Noising Based on Wavelet Theory 刘向红 LIU Xiang- hong 1 first-author 赵正予 ZHAO Zheng- yu 1 谢树果 XIE Shu- guo 1 武汉大学电子信息学学院,湖北,武汉,430072 武汉大学电子信息学学院,湖北,武汉,430072 College of Electronics Inform ation,Wuhan U niversity,Wuhan 0 72 College of Electronics Inform ation,Wuhan U niversity,Wuhan 0 72 利用小波变换良好的时 -频局部化性质和多分辨率分析特性 ,将含噪地磁微脉动信号中的有用信号与噪声区分开来 ,通过对高频系数进行阈值化处理 ,再经小波重构后的信号 ,实现了对原磁微脉动信号的消噪 .结果表明 :选用适当的小波 ,采取合适的阈值选择规则和比例调整方式 ,可以很好地实现对地磁微脉动信号的消噪处理 .处理结果与传统分析方法比较 ,具有不可比拟的优越性 . Wavelet transform is characterized with good time- frequency localization property.By applying the multi- resolution analysis of the original geomagnetic micro pulsations ,the signal and noise can be efficiently separated. Then adding a threshold in the decomposition detail coefficients,the reconstructed geomagnetic pulsation signal has been well denoised based on the new high- frequency coefficients. Results show that heuristic SURE threshold and fixed form threshold are two good threshold selection rule in Pc type geomagnetic pulsations’noise elimination .The soft thresholding is recommented in geomagnetic pulsations’denoising. 小波 多分辨率分析 地磁脉动 消噪 wavelet multi- resolution analysis geomagnetic pulsation de- noising 10.14188/j.1671-8836.2000.05.026 TN911 国家自然科学基金资助项目!（ 4 990 40 10 ） 2000-05-01 2021-04-01 5