Comparison of methods for magnetotelluric impedance estimation
Tang Jing-tia · The Chinese Journal of Nonferrous Metals · 2013
The performances of different kinds of methods for magnetotelluric impedance estimation were compared.The method of generating magnetotelluric simulated data was introduced,the typical noise series was extracted from noisy data.The basic principles of four regression methods of least square estimator,M-regression estimator,bounded influence estimator and repeated median estimator were introduced.These methods were tested using a set of standard data.At last,simulated data added by noise at different levels were processed by the four different estimators and compared with the simulated results.The results show that the repeated median estimator is the most robust.When the noise exists in the magnetic channel,the results estimated by the bounded influence method are acceptable,which are more stable than those estimated by the M-regression method.So,in the magnetotelluric data processing,the repeated median method and bounded influence method are recommended.