Experimental study on human being detection using UWB radar

In this paper we are evaluating the feasibility of using an UWB radar as a victim search device in emergency situations. The idea of human being detection using UWB radar is to observe periodic differences in time-of-arrival of scattered pulses from the victim, which are result of periodic movements of the chest area of the victim. This motion cannot be assumed to be uniform in all directions. We therefore investigate how the breathing motion, and thus detectability, of the human body for different angles of incidence and position of the body. The observed results show that the breathing motion in sitting position is most pronounced for body facing the radar, becomes less pronounced for 45° orientation only to become barely observable for 90° and 180°. For 45° and 90° one could observe periodic movement of the arm closer to the radar and that the arm attenuates the scattered signal from the lung. The horizontal positions of the body did not show any periodic movements, except for the case of front of the body facing the radar. Vertical co-polarization produced roughly the same results as horizontal one, whereas cross-polarization did not produce any output. It was observed that the breathing motion is proportional to an absolute value of a sinusoidal signal with its frequency being the breathing frequency.