Towed EM System Data - Error Analysis

A fast and efficient way to collect marine Controlled Source Electromagnetic (CSEM) data is to utilize a single-vessel Towed EM acquisition system featuring both streamer based electric field receivers (instead of static nodes), and a towed electric current bi-pole. The total error as standard deviation of the frequency responses has been quantified for a newly developed prototype Towed EM System. The calculation is based on data acquired in the North Sea during a field trial in November 2011. Contributions of the uncertainties in the measurement system calibration, navigation data and processing together with the electric field noise are stochastically added to give an estimation of the total error. The result shows that the maximum total relative percentage error is less than 2% for frequencies between 0.1 and 1.0 Hz. The electric field noise as a relative error part is verified with a Bayesian estimation of the frequency responses which automatically gives a measure of the uncertainty.