1887

Abstract

In this paper a theoretical and experimental analysis of 3 component marine CSEM electric field data is performed in order to study the effect of dipole oscillation in the sensing device. It is shown that the process of oscillation in time yields an spectral convolution between the spectrum of the recorded signal and that of the angular orientation. For a periodic waveform such as the exciting signal in CSEM the spectral distribution of the energy is found to smeared across harmonic lines of the spectrum. This yields added noise at both even and odd multiples of the fundamental frequency of the source function. Experimental evidence of the effect shows that non-vanishing even harmonics display a geometrical fall off with distant to the source. Therefor the strength of the noise added to one component (say $E_Z$) is correlated with the broadcasted signal. Lastly the spectrum of the even harmonics is used to estimate the spectral distribution of the mechanical oscillation of the arm. The analysis shows that the spectrum of oscillation peaks to a few (2-3) degrees at low frequencies and it decays as the frequency increases.

/content/papers/10.3997/2214-4609.20149443
2011-05-23
2022-01-19