Shadowing effect investigation for the purposes of person detection and tracking by UWB radars

Ultra wideband (UWB) radar appears as the new reliable upcoming technology well suited for detection and tracking of people in critical situations and environments. Our experiences with such applications of UWB radar systems have shown that at multiple moving person scenarios, a single radar with a small antenna array is able to detect very often the person moving closest to the radar antennas only, whereas the other target (persons) are also detected but usually with a small reliability. This effect can be explain in such a way that the person located closest to the radar antenna array manifest itself as an obstacle and creates an area with an additional attenuation behind him/her. In this paper, the quantitative description and analysis of shadowing phenomenon will be presented. For studying the properties of the mutual shadowing, the series of measurements with short range UWB radar were carried out. The obtained results indicate that the existence of additional attenuation within the shadow zones was confirmed.