a concealed object detection system for detecting objects concealed on a person includes radar transponders that are each configured and positioned to direct a radar signal at a person and to detect a portion of the radar signal reflected by the person . a processor connected to the radar transponders processes the portions of the radar signals detected by the radar transponders to determine whether the person is carrying a concealed object . the system may produce a real - time alert , such as an audible alert , when a concealed object is detected .