摘要
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.
出处
《武汉大学学报（自然科学版）》
CSCD
2000年第5期629-632,共4页
Journal of Wuhan University(Natural Science Edition)
基金
国家自然科学基金资助项目!( 4 990 40 10 )
关键词
多分辨率分析
地磁脉动
消噪
小波理论
wavelet
multi- resolution analysis
geomagnetic pulsation
de- noising
