Formulation of a method for the optimization of coils for electromagnetic induction systems in the presence of magnetic soil

Continuous-wave (CW) electromagnetic induction (EMI) systems operating in the presence of magnetic soil often encounter issues with the voltage that the soil induces in the receive coil. A formulation is developed to allow the calculation of the soil response of a CW EMI coil head that is represented by stream functions. This formulation is then included in an optimization procedure for stream-function coils that is designed to optimize a coil head for improved sensitivity while nulling the coil head´s soil response at a specific height above the soil. Example coils are created using the optimization method, and the new coils are compared to other common coil types.