Abstract: A method for determining a formation response form a detected electromagnetic signal resulting from a first electromagnetic signal imparted into a subsurface earth formation and from a second electromagnetic signal imparted into the formation, the first and second signals being imparted substantially contemporaneously. The detected signals are deconvolved using the first electromagnetic signal. The deconvolved detected signal is used to estimate the formation response to the first electromagnetic signal. Convolving the estimated formation response from the estimated formation response with the first electromagnetic signal and subtracting a result of the convulsion with the first electromagnetic signal from the detected signal.