Topographic Effect Of Transient Electromagnetic Responses

A three dimensional body is designed to simulate the valley shaped topography. Transient responses are<br>calculated for topography at source location and at receiver location respectively. Modeling results are shown<br>by relative anomalies in contours. The behavior of the topographic effect to transient eletromagnetic field<br>responses can be characterized by local anomaly for topography at receiver location, and by equivalently an<br>extra source with strong high frequency excitation for topography at source location. Learning from the<br>modeling results, it is emphasized that the ground wire source shall be set up at place as uniform as possible<br>for reliable deep sounding measurements.