An Evaluation of Robust Remote Reference and Parametric Magnetotelluric Transfer Function Estimation

The conventional approach to estimate the magnetotelluric (MT) impedance tensor from surface measured magnetic and geomagnetic electrical field time series relies on a frequency domain formulation and measurements from a remote reference site to mitigate correlated, systematic noise. Guided by system identification principles, we propose a parametric, time-domain approach that potentially offers greater statistical efficiency and noise resilience. Based on a study from measured data, we demonstrate that the parametric approach can yield estimates of the MT impedance with as little as one day of data and without the need of a remote reference site.