Accurate 3-dimensional image expansion algorithm using range derivative of double scattered signals for UWB radars

UWB(Ultra Wideband) radar offers a high range resolution and has a great promise to the near field sensing system, such as robotic or security sensor, that can identify a target even in an optically harsh environment. In recent years, some of radar imaging algorithms proactively employing multiple scattered components have been developed, which can enhance an imaging range compared to that synthesized by a single scattered one. As such, we have already proposed the SAR (Synthetic Aperture Radar) method using double scattered signals, and it successfully expanded a reconstructible range of radar imagery without any preliminary knowledge of target or surroundings. However, it is based on the multiple integration of the received signals, that requires an intensive computation, and also its spatial resolution is generally insufficient for clear boundary extraction such as edge or specular surface. As a substantial solution for the above problems, this paper proposes a novel expanded 3-dimensional (3-D) imaging algorithm based on range derivatives of double scattered signals. Some results in numerical simulations verify that the proposed method remarkably enhances the visible range of radar imagery without any integration process, and extremely decreases the calculation amount compared to that of the conventional method.