Theoretical response of vertical coincident and horizontal coplanar coils when operated over steeply dipping conductors located below a conductive overburden

Abstract

Theory for the electromagnetic response of a single‐turn, loaded‐coil target conductor located below a conductive overburden is developed for the case of moving source electromagnetic systems. Application of this theory to a comparative study of the horizontal coplanar and vertical coincident coil configurations demonstrates that the secondary magnetic field detected by a vertical coincident coil configuration over a steeply dipping tabular target located in free space is significantly stronger than the secondary field detected by the separated horizontal coplanar coil system over that same target for all target depths. In the presence of an overburden, this relative strength of anomaly magnitude is retained. In addition, the response of the coil target to the vertical coincident coil system is found to be less distorted by the presence of the overburden than when detected by the separated horizontal coplanar coils.