A TEM Based weak Signal Extraction Method of MRS Under Strong Noise in Tunnel

Abstract

Underground magnetic resonance sounding (MRS) low signal-noise ratio (SNR) weak signal is hard to manage with traditional de-noising method such as fitting and filter. In view of this, this article makes use of both transient electromagnetic method (TEM) data and MRS data obtained from integrated detecting equipment. The goal is to extract weak MRS signal based on TEM under strong background noise. At first, underground electrical distribution can be acquired from TEM data, which is processed by equivalent conductive plane method. Then, the initial model of moisture content distribution was constructed on geological information and 3D MRS forwarding was made with finite element method. At last, the correlation coefficient series and deviations between forwarding data and measured data were calculated. The initial model would be corrected until the result is satisfying. Model calculation shows that this method can effectively extract the weak nuclear magnetic signals in tunnel under strong background noise. Keywords—MRS; weak signal; TEM