The Research and Realization of Digital Power Line Interference Filter in Magnetotelluric

Magnetotelluric takes natural electromagnetic as field source to study the earth interior electrical structures. The observations are easy to be interfered by power line interference, so this paper designed a convenience and effective notch filter which could eliminate all of the high-order harmonics within the sampling rate. The notch filter was achieved by interpolation for band-stop filter and different interpolation could meet different trap frequency. After finishing the target notch filter, a series of simulation experiment and the practical test were conducted and the results shown that this notch filter could remove the power line interference effectively and could greatly improve the signal to noise ratio.