Patent · US Expired

Object detection method and apparatus employing polarized radiation

US6342696B1 · kind B1 · utility

56Cited by
98References
9Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 25, 1999
Grant dateJan 29, 2002
Priority date—
Expiry dateMay 25, 2019

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01S7/2883
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

Methods and apparatus for detecting objects are disclosed. In one embodiment of the invention, a person entering a secured or “Safe Zone™” is illuminated with low-power polarized radio waves. Differently polarized waves which are reflected back from the person are collected and measured. Persons carrying a concealed weapon such as a handgun are detected by calculating the difference of a pair of differences between levels of different polarized reflected energy. 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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.