Wavelet Maxima Method for Identifying Singularities in Electromagnetic Signal

Wavelet maxima method as a kind of data mining method has been applied to earthquake science research,which gives us a direct way to identify the singularities of different time and frequencies in the long time observations. This paper introduces how to identify the electromagnetic anomalies using the wavelet maxima,i.e.,the wavelet coefficients are calculated by using continuous wavelet transform and then calculate the maximum value of wavelet coefficients in each scale and identify the singularities associated with the earthquake. The identified singularities are further examined by Lipschitz-exponent α. The proposed method has been employed using the 35 days' data of the electromagnetic field recorded in Baosheng station in Sichuan after the Lushan MS7. 0 earthquake,and three electromagnetic anomalies are collected,then,the relationships between the electromagnetic anomalies and the earthquakes are discussed. This method cannot give a certain relationship between the electromagnetic anomaly and earthquake,but it proves the method's effectiveness in extracting the electromagnetic anomaly in continuous observation data.