estimation of harmonic interference parameters of surfacenmr signal using an adaptive method and residual signal power

Surface nuclear magnetic resonance (surfacenmr) method is a wellknown tool for determining the waterbearing layers and subsurface resistivity structure. harmonic interference is an inevitable interference in surfacenmr measurements. accurate estimation of harmonic interference parameters (i.e., fundamental frequency, phase and amplitude) leads to better retrieval of powerline harmonics and consequently, more effective suppression of harmonics from surfacenmr recordings. to that end, two algorithms are addressed for isolation and then subtraction of harmonic interfering noise based on modeling of powerline harmonics by a modified version of nymangaiser estimation (nge) and residual signal power (rsp) technique. then, the results derived from the proposed algorithms are analyzed and compared through the modeling of some synthetic signals embedded in simulated noise and real recordings obtained from multichannel surfacenmr measurements. the numerical experiments on simulated and real surfacenmr signals show that the application of the proposed procedures results in significant decline of the level of the standard deviation of imaginary part of the detected signal and consequently, relatively accurate recovery of the harmonic signal components with an accompanying enhancement in estimation of the surfacenmr signal parameters.