Space-time array difference magnetotelluric method

A space-time array difference magnetotelluric method is proposed in order to suppress the correlated noise and obtain reliable plane wave impedance data in strong interference region. First, we established a model of electromagnetic prospecting system with multi-input and multi-output. Both natural and man-made electromagnetic field is considered to incidence to earth simultaneously, constitute a space-time array input. Many stations are carried out to simultaneously observe the total responses of all the inputs on the earth's surface, constitute a space-time array output. A set of quadratic space-time equations is obtained by resolving the input-output relationship of the linear time invariant system.