In some ground penatrating applications, it is required to deduce the physical properties of the medium or object under study, such as the size, shape and electrical characteristics, from the transient scattered field measured at a set of receivers outside the scatterer due to a collection of transmitters. In this study, wide-band antenna and radar systems was considered. The FDTD method was used to solve transient scattering problem in an arbitrary two-dimensional inhomogeneous, isotropic medium. The measured transient response of the object is analyzed. Two dimensional detection algorithm is developed by using the frequency domain Green's function. Some results are given, and comparisons are made between different physical configurations.