Materials classifier
AssigneeBAE SYSTEMS plc
InventorsLionel William John Kent, Jason John Lepley
Life of this patent
Estimating the term…
Abstract
A method and apparatus for classifying and/or identifying materials by means of their spectral response to gamma radiation. Classification is carried out by irradiating multiple different samples with gamma radiation, detecting a spectral response in the backscatter direction, sorting the spectral response into energy bands and selecting a combination of energy bands to define a relationship that best distinguishes between clusters of spectral responses for different material classes. Two or more of the energy bands may overlap.
Claims20
A materials classifier for use in detecting the presence of at least one material or material type in a sample under test, the materials classifier comprising:
- a gamma radiation source holder for holding at least one gamma radiation source for irradiating a sample test location;
- a detector for detecting radiation events in a backscatter direction from the sample test location, the radiation events lying in at least three different detected energy bands;
- and
- a classifying analyser for analyzing two or more relationships between detected radiation events in the at least three different detected energy bands, the analysis being carried out for multiple different materials or material types,
- the classifying analyser being configured to combine two or more of the detected radiation events into a first cluster of radiation events within a first one of the at least three different detected energy bands and to combine two or more of the detected radiation events into a second cluster of radiation events within a second one of the at least three different detected energy bands,
- the classifying analyser being configured to compare count values for each of the detected radiation events lying in the first cluster of radiation events against count values for each of the detected radiation events lying in the second cluster of radiation events,
- the classifying analyser being configured to select one or more preferred relationships for distinguishing between the different materials or material types based on the comparison.
A method of classifying materials by means of their spectral response to gamma radiation, the method comprising;
- irradiating multiple different samples with gamma radiation;
- detecting radiation events in the backscatter direction, the radiation events lying in at least two detected energy bands;
- sorting the detected radiation events into at least two detected_energy bands;
- combining two or more of the detected radiation events into a first cluster of radiation events within a first one of the at least two detected energy bands and combining two or more of the detected radiation events into a second cluster of radiation events within a second one of the at least two detected energy bands;
- comparing count values for each of the detected radiation events lying in the first cluster of radiation events against count values for each of the detected radiation events lying in the second cluster of radiation events;
- and
- selecting a combination of the at least two detected energy bands to define at least one relationship that best distinguishes between clusters of spectral responses for different material classes based on the comparison.
A system for use in detecting the presence of at least one material or material type in a sample under test, the system comprising:
- a gamma radiation source holder for holding at least one gamma radiation source for irradiating a sample test location;
- a detector for detecting radiation events in a backscatter direction from the sample test location, the events lying in at least three different detected energy bands;
- and
- a classifying analyser for analyzing two or more relationships between detected radiation events in the at least three different detected energy bands, the analysis being carried out for multiple different materials or material types, the classifying analyser being configured to (1) to compare count values for detected events lying in respective ones of the at least three different energy bands, wherein two or more of the detected radiation events are combined into a first cluster of radiation events within a first one of the at least three different detected energy bands and two or more of the detected radiation events are combined into a second cluster of radiation events within a second one of the at least three different detected energy bands, and (2) select a preferred relationship for distinguishing between the at least two different materials or material types based on the comparison.
Dependencies are inferred from the claim text.