Ground detection by a single electromagnetic far-field measurement

We consider detecting objects on a flat ground by using the electromagnetic (EM) measurement made from a height. Our study is conducted in a very general and practical setting. The number of the target scatterers is not required to be known in advance, and each scatterer could be either an inhomogeneous medium or an impenetrable perfectly conducting (PEC) obstacle. Moreover, there might be multiscale components of small-size and extended-size (compared to the detecting wavelength) presented simultaneously. Some a priori information is required on scatterers of extended-size. The inverse problem is nonlinear and ill-conditioned. We propose a "direct" locating method by using a single EM far-field measurement. The results extend those obtained in [17,18] for locating multiscale EM scatterers located in a homogeneous space.