US5078952A — Multi-sensor explosive detection system

Claim 1

Independent Claim 199 words

An explosive detection system comprising: (a) a source of neutrons; (b) a detector array comprising a plurality of gamma ray detectors, each of said gamma ray detectors providing a detection signal in the event a gamma ray is captured by said detector, and at least one neutron detector, said neutron detector providing a neutron detection signal in the event a neutron is captured by said neutron detector; (c) means for irradiating an object being examined with neutrons from the neutron source and for positioning the detector array relative to the object so that gamma rays emitted from the elements within the object as a result of said neutron irradiation are detected by the gamma ray detectors of said detector array; and (d) parallel distributed processing means responsive to the detection signals of said detector array for discriminating between objects carrying explosives and objects not carrying explosives, said parallel distributed processing means including an artificial neural system (ANS), said ANS having a parallel network of processors, each processor of said parallel network of processors including means for receiving at least one input signal, and means for generating an output signal as a function of said at least one input signal.

Claim 2

Dependent Claim 199 words

An explosive detection system comprising: (a) a source of neutrons; (b) a detector array comprising a plurality of gamma ray detectors, each of said gamma ray detectors providing a detection signal in the event a gamma ray is captured by said detector, and at least one neutron detector, said neutron detector providing a neutron detection signal in the event a neutron is captured by said neutron detector; (c) means for irradiating an object being examined with neutrons from the neutron source and for positioning the detector array relative to the object so that gamma rays emitted from the elements within the object as a result of said neutron irradiation are detected by the gamma ray detectors of said detector array; and (d) parallel distributed processing means responsive to the detection signals of said detector array for discriminating between objects carrying explosives and objects not carrying explosives, said parallel distributed processing means including an artificial neural system (ANS), said ANS having a parallel network of processors, each processor of said parallel network of processors including means for receiving at least one input signal, and means for generating an output signal as a function of said at least one input signal.

Claim 3

Dependent Claim 47 words

The explosive detection system as set forth in claim 1 further including spectral correlation means for removing noise from the gamma ray detection signals generated by said gamma ray detectors, whereby only gamma rays having a selected energy level are accepted by said parallel distributed processing means.

Claim 4

Dependent Claim 52 words

The explosive detection system as set forth in claim 1 further including X-ray means for generating an electron density image of said object, said means for utilizing said electron density image in combination with the detection signals from said detector array to discriminate between objects carrying explosives and objects not carrying explosives.

Claim 5

Dependent Claim 73 words

The explosive detection system as set forth in claims 1, 2, or 3 wherein said parallel network of processors includes a plurality of layers of said processors, a first layer of said processors receiving as an input signal a detection signal from one of said plurality of detectors, a last layer of said processors providing a plurality of output signals that classify said objects as objects carrying explosives and objects not carrying explosives.

Claim 6

Dependent Claim 51 words

The explosive detection system as set forth in claim 4, further including means for applying an adjustable weighting factor to the at least one input signal of each processor, whereby the output signals that classify said objects can be adjusted to properly classify said objects through adjustment of said weighting factors.

Claim 7

Dependent Claim 75 words

The explosive detection system as set forth in claims 1, 2 or 3 wherein said parallel network of processors includes a plurality of layers of said processors, a first layer of said processors receiving as an input signal a feature signal derived from a selected combination of said detector signals, a last layer of said processors providing a plurality of output signals that classify said objects as objects carrying explosives and objects not carrying explosives.

Claim 8

Dependent Claim 51 words

The explosive detection system as set forth in claim 6 further including means for applying an adjustable weighting factor to the at least one input signal of each processor, whereby the output signals that classify said objects can be adjusted to properly classify said objects through adjustment of said weighting factors.

Claim 9

Dependent Claim 245 words

An explosive detection system comprising: (a) a source of neutrons; (b) at least one detector array comprising a plurality of gamma ray detectors, each of said detectors providing a detection signal in the event a gamma ray is captured by said detector; (d) a neutron detector; (c) means for bombarding an object being examined with neutrons from the neutron source and for positioning the detector array relative to the object so that gamma rays emitted from the elements within the object as a result of said neutron bombardment are detected by the gamma ray detectors of said detector array; and (d) parallel distributed processing means responsive to the detection signals of said detector array and neutron detector for discriminating between objects carrying explosives and objects not carrying explosives, said parallel distributed processing means comprising a parallel network of processors, each processor of said parallel network of processors including means for receiving at least one input signal, and means for generating an output signal as a function of said at least one input signal, said parallel network of processors including a plurality of layers of said processors, a first layer of said processors receiving as an input signal a feature signal derived from a selected combination of said detection signals, a last layer of said processors providing a plurality of output signals that classify said objects as either objects having a high probability of carrying explosives or objects having a high probability of not carrying explosives.

Claim 10

Dependent Claim 245 words

An explosive detection system comprising: (a) a source of neutrons; (b) at least one detector array comprising a plurality of gamma ray detectors, each of said detectors providing a detection signal in the event a gamma ray is captured by said detector; (d) a neutron detector; (c) means for bombarding an object being examined with neutrons from the neutron source and for positioning the detector array relative to the object so that gamma rays emitted from the elements within the object as a result of said neutron bombardment are detected by the gamma ray detectors of said detector array; and (d) parallel distributed processing means responsive to the detection signals of said detector array and neutron detector for discriminating between objects carrying explosives and objects not carrying explosives, said parallel distributed processing means comprising a parallel network of processors, each processor of said parallel network of processors including means for receiving at least one input signal, and means for generating an output signal as a function of said at least one input signal, said parallel network of processors including a plurality of layers of said processors, a first layer of said processors receiving as an input signal a feature signal derived from a selected combination of said detection signals, a last layer of said processors providing a plurality of output signals that classify said objects as either objects having a high probability of carrying explosives or objects having a high probability of not carrying explosives.

Claim 11

Dependent Claim 225 words

Apparatus for non-invasively detecting explosives in an object under investigation comprising: means for generating thermal neutrons; means for irradiating said object with said thermal neutrons, the interactions of said thermal neutrons with atomic nuclei within said object giving rise to the emission of gamma rays, said gamma rays having an energy level characteristic of the nuclear species contained in said object; gamma ray detection means for detecting emitted gamma rays having an energy level characteristic of at least one element and for roughly determining the location within said object from which the detected gamma rays originated, the detection of said gamma rays and their source location thereby providing a measure of the density distribution of said at least one element within said object; neutron detection means for detecting neutrons that pass through said object without interacting with atomic nuclei, the detection of said neutrons thereby providing a measure of the density distribution of all materials within said object, including said at least one element; image means responsive to said gamma ray and neutron detection means for generating a three-dimensional density image of said at least one element within said object; and an artificial neural system, said artificial neural system including recognition means responsive to said gamma ray and neutron detection means for recognizing a pattern of detected gamma rays and neutrons indicative of an explosive.

Claim 12

Dependent Claim 225 words

Apparatus for non-invasively detecting explosives in an object under investigation comprising: means for generating thermal neutrons; means for irradiating said object with said thermal neutrons, the interactions of said thermal neutrons with atomic nuclei within said object giving rise to the emission of gamma rays, said gamma rays having an energy level characteristic of the nuclear species contained in said object; gamma ray detection means for detecting emitted gamma rays having an energy level characteristic of at least one element and for roughly determining the location within said object from which the detected gamma rays originated, the detection of said gamma rays and their source location thereby providing a measure of the density distribution of said at least one element within said object; neutron detection means for detecting neutrons that pass through said object without interacting with atomic nuclei, the detection of said neutrons thereby providing a measure of the density distribution of all materials within said object, including said at least one element; image means responsive to said gamma ray and neutron detection means for generating a three-dimensional density image of said at least one element within said object; and an artificial neural system, said artificial neural system including recognition means responsive to said gamma ray and neutron detection means for recognizing a pattern of detected gamma rays and neutrons indicative of an explosive.

Claim 13

Dependent Claim 55 words

Explosive detection apparatus as set forth in claim 9 further including: means for generating at least one two-dimensional electron density image of said object; and means for combining said at least one element density image and said electron density image and for determining whether said combined image indicates the presence of explosives within said object.

Claim 14

Dependent Claim 56 words

Explosive detection apparatus as set forth in claim 10 wherein said electron density image generation means includes means for generating two two-dimensional electron density images of said object, a first electron density image lying in a first plane, and a second electron density image lying in a second plane that is orthogonal to said first plane.

Claim 15

Dependent Claim 45 words

Explosive detection apparatus as set forth in claim 9 wherein said recognition means of said artificial neural system includes means for automatically adjusting the patterns it recognizes as belonging to explosives based on detected patterns of gamma rays and neutrons from objects containing known explosives.

Claim 16

Dependent Claim 41 words

Explosive detection apparatus as set forth in claim 9 or 10 wherein said gamma ray detection means includes means for rejecting background noise in the detected gamma rays, said background noise including the detection of gamma rays emitted from non-explosive elements.

Claim 17

Dependent Claim 67 words

Explosive detection means as set forth in claim 13 wherein said means for rejecting background noise includes spectral correlation means for measuring background noise at a first location in the detected gamma ray spectrum and subtracting said background noise from a second location in the gamma ray spectrum, said second location in the gamma ray spectrum corresponding to gamma rays resulting from neutron interaction with nitrogen nuclei.

Claim 18

Dependent Claim 264 words

Apparatus for non-invasively detecting explosives in an object under investigation comprising: means for generating thermal neutrons; means for irradiating said object with said thermal neutrons, the interactions of said thermal neutrons with atomic nuclei within said object giving rise to the emission of gamma rays, said gamma rays having an energy level characteristic of the nuclear species contained in said object; gamma ray detection means for detecting emitted gamma rays having an energy level characteristic of at least one specific element and for roughly determining the location within said object from which the detected gamma rays originated, the detection of said gamma rays and their source location thereby providing a measure of the density distribution of said at least one specific element within said object; neutron detection means for detecting neutrons that pass through said object without interacting with atomic nuclei, the detection of said neutrons thereby providing a measure of the density distribution of all materials within said object, including said at least one element; X-ray means for generating at least one two-dimensional electron density image of said object; and determining means for combining said measure of the density distribution of all materials within said object, including said at least one specific element, with said electron density image, and for determining whether said combined measure and image indicate the presence of explosives within said object, said determining means including an artificial neural system, said artificial neural system having recognition means responsive to said gamma ray and neutron detection means for recognizing a pattern of detected gamma rays and neutrons indicative of an explosive.

Claim 19

Dependent Claim 264 words

Apparatus for non-invasively detecting explosives in an object under investigation comprising: means for generating thermal neutrons; means for irradiating said object with said thermal neutrons, the interactions of said thermal neutrons with atomic nuclei within said object giving rise to the emission of gamma rays, said gamma rays having an energy level characteristic of the nuclear species contained in said object; gamma ray detection means for detecting emitted gamma rays having an energy level characteristic of at least one specific element and for roughly determining the location within said object from which the detected gamma rays originated, the detection of said gamma rays and their source location thereby providing a measure of the density distribution of said at least one specific element within said object; neutron detection means for detecting neutrons that pass through said object without interacting with atomic nuclei, the detection of said neutrons thereby providing a measure of the density distribution of all materials within said object, including said at least one element; X-ray means for generating at least one two-dimensional electron density image of said object; and determining means for combining said measure of the density distribution of all materials within said object, including said at least one specific element, with said electron density image, and for determining whether said combined measure and image indicate the presence of explosives within said object, said determining means including an artificial neural system, said artificial neural system having recognition means responsive to said gamma ray and neutron detection means for recognizing a pattern of detected gamma rays and neutrons indicative of an explosive.

Claim 20

Dependent Claim 56 words

Explosive detection apparatus as set forth in claim 15 wherein said electron density image generation means includes means for generating two two-dimensional electron density images of said object, a first electron density image lying in a first plane, and a second electron density image lying in a second plane that is orthogonal to said first plane.

Claim 21

Dependent Claim 43 words

Explosive detection apparatus as set forth in claim 15 wherein said recognition means of said artificial neural system includes means for automatically adjusting the patterns it recognizes as belonging to explosives based on detected patterns of gamma rays from objects containing known explosives.

Claim 22

Dependent Claim 27 words

Explosive detection apparatus as set forth in claim 15 wherein said artificial neural system is further responsive to the electron density images obtained from said X-ray means.

Claim 23

Dependent Claim 39 words

Explosive detection apparatus as set forth in claim 15 wherein said gamma ray detection means includes means for rejecting background noise in the detected gamma rays, said background noise including the detection of gamma rays emitted from non-explosive elements.

Claim 24

Dependent Claim 51 words

Explosive detection apparatus as set forth in claim 19 further including neutron detection means for detecting neutrons that pass through said object without interacting with atomic nuclei, the detection of said neutrons thereby providing a measure of the density distribution of all materials within said object, including nitrogen, hydrogen, and chlorine.

Claim 25

Dependent Claim 289 words

Apparatus for non-invasively detecting explosives in an object under investigation comprising: means for generating thermal neutrons; means for irradiating said object with said thermal neutrons, the interactions of said thermal neutrons with atomic nuclei within said object giving rise to the emission of gamma rays, said gamma rays having an energy level characteristic of the nuclear species contained in said object; gamma ray detection means for detecting emitted gamma rays having an energy level characteristic of at least one specific element and for roughly determining the location within said object from which the detected gamma rays originated, the detection of said gamma rays and their source location thereby providing a measure of the density distribution of said at least one specific element within said object; neutron detection means for detecting neutrons that pass through said object without interacting with atomic nuclei, the detection of said neutrons thereby providing a measure of the density distribution of all materials within said object, including said at least one element; an artificial neural system, said artificial neural system including recognition means responsive to said gamma ray detection means for recognizing a pattern of detected gamma rays and neutrons indicative of an explosive, said recognition means including means for automatically adjusting the patterns it recognizes as belonging to explosives based on detected patterns of gamma rays and neutrons from objects containing known explosives; image means responsive to said gamma ray detection means for generating a three-dimensional density image of said at least one specific element within said object; determining means responsive to said artificial neural system and said image means for determining whether said three-dimensional density image of said at least one specific element density image indicates the presence of explosives within said object.

Claim 26

Dependent Claim 289 words

Apparatus for non-invasively detecting explosives in an object under investigation comprising: means for generating thermal neutrons; means for irradiating said object with said thermal neutrons, the interactions of said thermal neutrons with atomic nuclei within said object giving rise to the emission of gamma rays, said gamma rays having an energy level characteristic of the nuclear species contained in said object; gamma ray detection means for detecting emitted gamma rays having an energy level characteristic of at least one specific element and for roughly determining the location within said object from which the detected gamma rays originated, the detection of said gamma rays and their source location thereby providing a measure of the density distribution of said at least one specific element within said object; neutron detection means for detecting neutrons that pass through said object without interacting with atomic nuclei, the detection of said neutrons thereby providing a measure of the density distribution of all materials within said object, including said at least one element; an artificial neural system, said artificial neural system including recognition means responsive to said gamma ray detection means for recognizing a pattern of detected gamma rays and neutrons indicative of an explosive, said recognition means including means for automatically adjusting the patterns it recognizes as belonging to explosives based on detected patterns of gamma rays and neutrons from objects containing known explosives; image means responsive to said gamma ray detection means for generating a three-dimensional density image of said at least one specific element within said object; determining means responsive to said artificial neural system and said image means for determining whether said three-dimensional density image of said at least one specific element density image indicates the presence of explosives within said object.

Claim 27

Dependent Claim 39 words

Explosive detection apparatus as set forth in claim 21 wherein said gamma ray detection means includes means for rejecting background noise in the detected gamma rays, said background noise including the detection of gamma rays emitted from non-explosive elements.

Claim 28

Dependent Claim 66 words

Explosive detection means as set forth in claim 22 wherein said means for rejecting background noise includes spectral correlation means for measuring background noise at a first location in the detected gamma ray spectrum and subtracting said background noise from a second location in the gamma ray spectrum, said second location in the gamma ray spectrum corresponding to gamma rays resulting from neutron interaction with nuclei.

Claim 29

Dependent Claim 235 words

Apparatus for non-invasively detecting explosives in an object under investigation comprising: means for generating thermal neutrons; means for irradiating said object with said thermal neutrons, the interactions of said thermal neutrons with atomic nuclei within said object giving rise to the emission of gamma rays, said gamma rays having an energy level characteristic of the nuclear species contained in said object; gamma ray detection means for detecting emitted gamma rays having an energy level characteristic of at least one specific element and for roughly determining the location within said object from which the detected gamma rays originated, said gamma ray detection means including means for rejecting background noise in the detected gamma rays, said background noise including the detection of gamma rays emitted from non-explosive elements, the detection of said gamma rays and their source location thereby providing a measure of the density distribution of said at least one specific element within said object; neutron detection means for detecting neutrons that pass through said object without interacting with atomic nuclei, the detection of said neutrons thereby providing a measure of the density distribution of all materials within said object, including said at least one element; determining means responsive to said measure of the density distribution of the materials, including said at least one specific element, within said object for determining whether said object likely contains an explosive, said determining means including an artificial neural system.

Claim 30

Dependent Claim 235 words

Apparatus for non-invasively detecting explosives in an object under investigation comprising: means for generating thermal neutrons; means for irradiating said object with said thermal neutrons, the interactions of said thermal neutrons with atomic nuclei within said object giving rise to the emission of gamma rays, said gamma rays having an energy level characteristic of the nuclear species contained in said object; gamma ray detection means for detecting emitted gamma rays having an energy level characteristic of at least one specific element and for roughly determining the location within said object from which the detected gamma rays originated, said gamma ray detection means including means for rejecting background noise in the detected gamma rays, said background noise including the detection of gamma rays emitted from non-explosive elements, the detection of said gamma rays and their source location thereby providing a measure of the density distribution of said at least one specific element within said object; neutron detection means for detecting neutrons that pass through said object without interacting with atomic nuclei, the detection of said neutrons thereby providing a measure of the density distribution of all materials within said object, including said at least one element; determining means responsive to said measure of the density distribution of the materials, including said at least one specific element, within said object for determining whether said object likely contains an explosive, said determining means including an artificial neural system.

Claim 31

Dependent Claim 72 words

Explosive detection means as set forth in claim 24 wherein said means for rejecting background noise within said gamma ray detection means includes spectral correlation means for measuring background noise at a first location in the detected gamma ray spectrum and subtracting said background noise from a second location in the gamma ray spectrum, said second location in the gamma ray spectrum corresponding to gamma rays resulting from neutron interaction with nuclei.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1995-01-06	1995-07-08	1996-01-07	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1999-01-06	1999-07-08	2000-01-07	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2003-01-06	2003-07-08	2004-01-07	$7700.00	Window Closed / Lapsed

Multi-sensor explosive detection system

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