Portal monitoring
First Claim
1. A monitoring system for detecting the presence of metallic objects passing through a portal, comprising:
- a first length of optical fibre mechanically coupled to a material whose physical characteristics vary dependent on an ambient magnetic field, the optical fibre being arranged in the vicinity of the portal being monitored, wherein the portal defines a passage through which people and/or objects may pass and wherein the first length of optical fibre is deployed along at least two sides of the passage defined by the portal;
a fibre optic interrogator configured to provide distributed sensing on the optical fibre to provide measurement data from each of a plurality of sensing portions of said optical fibre at each of a plurality of times; and
a data analyser configured to process said measurement data to detect signals characteristic of a disturbance in the magnetic field along the optical fibre so as to detect the presence of a metallic object.
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Accused Products
Abstract
The present invention relates to a portal monitoring system that uses distributed sensing to detect metallic objects passing through the portal. The system comprises a length of fiber optic (102) comprising an optical fiber (106) mechanically coupled to a material (108) whose physical characteristics vary dependent on the applied magnetic field. The fiber optic (102) is arranged in the vicinity of a portal (200) and a fiber optic interrogator (104) is adapted to provide distributed sensing on the optical fiber to provide measurement data from a plurality of contiguous portions of said optical fiber at each of a plurality of times. A data analyzer processes the measurement data to detect signals characteristic of a disturbance in the magnetic field along the optical fiber. The system of the present invention is able to monitor multiple people passing though a portal at the same time and provide an indication of the location of metallic objects within the portal.
109 Citations
26 Claims
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1. A monitoring system for detecting the presence of metallic objects passing through a portal, comprising:
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a first length of optical fibre mechanically coupled to a material whose physical characteristics vary dependent on an ambient magnetic field, the optical fibre being arranged in the vicinity of the portal being monitored, wherein the portal defines a passage through which people and/or objects may pass and wherein the first length of optical fibre is deployed along at least two sides of the passage defined by the portal; a fibre optic interrogator configured to provide distributed sensing on the optical fibre to provide measurement data from each of a plurality of sensing portions of said optical fibre at each of a plurality of times; and a data analyser configured to process said measurement data to detect signals characteristic of a disturbance in the magnetic field along the optical fibre so as to detect the presence of a metallic object. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method of monitoring a portal defining a passage through which people and/or objects pass so as to detect the presence of metallic objects, the method comprising:
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interrogating an optical fibre, which is mechanically coupled to a material whose physical characteristics vary dependent on the ambient magnetic field, with pulses of electromagnetic radiation to provide a distributed sensor having a plurality of sensing portions of optical fibre, said optical fibre being arranged along at least two sides of the passage defined by the portal, and analysing the signals from each of said plurality of sensing portions of optical fibre to detect signals characteristic of a disturbance in the magnetic field in the portal so as to detect the presence of a metallic object. - View Dependent Claims (22, 23, 24, 25, 26)
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Specification