Analysis of the responses of the buried target in transient electromagnetic prospecting by FDTD

It is important to understand the response characteristic of the quasi-static transient electromagnetic field for identifying the target buried in the earth. The models including a target in a homogeneous earth and a target in a homogeneous earth with an overburden are simulated by finite-difference time-domain (FDTD) method. The results show that the conductive targets are easy to read and the resistive targets are difficult to read, while the conductive overburden which covers the anomalies caused by the targets forms a shield to the field and the resistive overburden has little effect to the prospecting. These analyses provide the estimation method to the capacity of transient electromagnetic prospecting.