A simple analysis of the electromagnetic response of buried conducting objects

A simple approach to the analysis of electromagnetic induction response of buried conducting objects is illustrated by deriving the step response of a sphere at an arbitrary location with respect to a sensor system. The result obtained is shown to be the same as that derived by T. Lee (Pure Appl. Geophys., vol.119, p.309-38, 1981), which is usually derived as a limiting case of a rather complex exact analysis. While the approach discussed is approximate (displacement currents are ignored and the exciting field is assumed to be uniform over the object), it has the advantage of being simple in concept and implementation and can be used to adequately analyze the response characteristics of practical detector systems