Noise Suppression for Surface Nuclear Magnetic Resonance Data Based on Frame Energy Spectrum Subtraction

Abstract

As an advanced groundwater detection instrument, surface nuclear magnetic resonance (NMR)instrument is having more attention on the field of international water exploration technology. However, the surface NMR instrument is very susceptible to electromagnetic interference (EMI) during measurement, and noise suppression is one of the key research issues in surface NMR field. We propose a novel noise suppression method for noisy surface NMR data based on frame energy spectral subtraction. In the method, it is to first allow surface NMR receiver to only collect noise data in the ambient environment, and then to sequentially perform surface NMR transmitter and receiver to record the noisy surface NMR data. Then we use frame energy spectrum subtraction method to deal with noisy surface NMR data and achieve noise suppression. Simulation experiment and field experiment demonstrate that the method can effectively suppress random noise and harmonic noise and improve signal-to-noise ratio (SNR). The method lays a foundation for the detection application of surface NMR instruments in strong EMI ambient environment, and provides a guarantee for the surface NMR inversion.