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Magnetic Resonance Sounding Signals Retrieval Based on Empirical Mode Decomposition and a Statistical Method
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, Near Surface Geoscience 2014 - 20th European Meeting of Environmental and Engineering Geophysics, Sep 2014, Volume 2014, p.1 - 5
Abstract
The technique of magnetic resonance sounding (MRS) is a non-invasive hydro-geophysical tool for estimating the distribution of water content and the pore size distribution with depth in the subsurface. It is well-know that the quality of MRS measurements is strongly affected by even very low noise. In the present study, in order to enhance the performance in the noisy environments, a two-step noise cancellation approach based on the empirical mode decomposition and a statistical method is proposed. In the first stage, a significant part of the signal noise is eliminated using the decomposition of the signal by the empirical mode decomposition algorithm and based on the detection and removal of the noisy IMFs. Then the de-noised signal is reconstructed through the no-noise information. In the second stage, the signal obtained from the initial section enters an optimization process to cancel the remnant noise, and consequently, estimate the signal parameters. The strategy is tested on a synthetic MRS signal contaminated with Gaussian noise, spiky events and harmonic noise. By applying successively the proposed steps, we can remove the noise from the signal to a high extent and the performance indexes, particularly signal to noise ratio, will increase significantly.