基于DWT-EEMD的盲源分离算法在MT工频干扰消除中的应用

摘要

The blind source separation algorithm based on DWT-EEMD used in noise elimination of power line interference for magnetotelluric is put forward in this paper.This method takes advantage of the excellent characteristics of DWT,EEMD and blind source separation,and adopts blind source separation to eliminate the noise after DWT and EEMD processing.The main advantage of this method lies in the DWT-EEMD model adopted and the introduction of the adaptive weighting factor,in reducing uncertainty of restored signal amplitude by independent component analysis algorithm at the same time,it has made the original signals still be well separated in condition of power frequency interference noise amplitude much higher than original signal amplitude.By the real magnetotelluric signal processing,it is showed that this method makes apparent resistivity curve and phase curve both become smooth and steady,and it better eliminates the power line interference noise in magnetotelluric signal.%为了消除大地电磁测深数据中的工频干扰,提出基于DWT-EEMD的盲源算法,利用DWT、EEMD和盲源分离的优良特性,在进行DWT和EEMD处理之后再进行盲源分离以消除噪声.该方法主要优势在于DWT-EEMD模型的采用和自适应权重因子的引入,在降低独立分量分析算法对恢复信号的幅值的不确定性的同时,使得在工频干扰噪声的幅值高于原始信号很多的情况下依然能较好地分离出原始信号.通过对实测大地电磁信号进行处理后发现,该方法使视电阻率曲线和相位曲线均变得平滑而稳定,较好地消除了大地电磁信号中的工频干扰噪声.