Patent ID: 6567496
Filing Date: 2003-05-20
Classification: G01N,G01V

Abstract:
A process for detecting contraband within a container comprising the steps of:scanning the container with x-rays along a first plane and obtaining a first sequence of one dimensional transmission intensity measurements from outputs of a plurality of x-ray sensors for a first x-ray intensity spectrum, and obtaining a second sequence for the first plane of one dimensional transmission intensity measurements from outputs of a plurality of x-ray sensors for a second x-ray intensity spectrum; scanning the container with x-rays along a second plane and obtaining a first sequence of a one dimensional transmission intensity measurements from outputs of a plurality of x-ray sensors for a first x-ray intensity spectrum, and obtaining a second sequence for the second plane of one dimensional transmission intensity measurements from outputs of a plurality of x-ray sensors for a second x-ray intensity spectrum; using said first plane first intensity spectrum sequence of one dimensional transmission intensity measurements and said first plane second intensity spectrum sequence of one dimensional transmission intensity measurements to calculate a sequence of first plane atomic number values and mass thickness values; using said second plane first intensity spectrum sequence of one dimensional transmission intensity measurements and said second plane second intensity spectrum sequence of one dimensional transmission intensity measurements to calculate a sequence of second plane atomic number values and mass thickness values; providing a first plane image by processing at least one of said first or second sequence of one dimensional transmission intensity measurements and providing a second plane image by processing at least one of said second plane first or second sequence of one dimensional transmission intensity measurements; identifying a suspicious area in at least one of said first plane image or said second plane image; using the atomic number values and mass thickness values calculated for said suspicious area to calculate an average atomic number value and an average density value for the suspicious area; and, comparing the average atomic number value and average density value for the suspicious area with known atomic number values and density values of actual contraband materials and providing an output indicative of whether the calculated average atomic number value and average density value for the suspicious area fall within those of an actual contraband material.