Methods and apparatus for detecting objects are disclosed. In one embodiment of the invention, a person entering a secured or "Safe Zone<TM>" is illuminated with low-power polarized radio waves. Differently polarized waves which are reflected back from the person are collected and measured. In a preferred embodiment of the invention, concealed weapons are detected by calculating the difference of a pair of differences between levels of different polarized reflected energy in the time domain, and by using signal processing methods and apparatus to improve the reliability of the detection process. Alternative embodiments of the invention may be used to detect a wide variety of objects other than concealed firearms. The invention may be used for inventory control or to thwart shoplifting.
申请公布号
WO0075892(A2)
申请公布日期
2000.12.14
申请号
WO2000US14509
申请日期
2000.05.25
申请人
SAFE ZONE SYSTEMS, INC.;CHADWICK, GEORGE, G.;WEAKLEY, THOMAS, C.