Abstract
Non-destructive testing (NDT) by x-ray imaging is commonly used for finding manufacturing defects, cargo inspection, or security screening. These tasks can be regarded as examples of a detection problem where a target is either present or not. Task-specific information (TSI) [J. Opt. Soc. Am. A 24, B25 (2007); Appl. Opt. 47, 4457 (2008)] bounds, an information-theoretic based metric, are presented for a threat detection task. A system using polychromatic x-ray pencil beam object illumination and energy-resolving detectors for both absorption and diffraction measurements is employed for this task. Water and diesel are two liquids chosen as non-threat and threat materials, respectively, for this study. Three different threat class configurations are examined: a homogeneous object with fixed thickness, a homogeneous object with stochastic thickness, and a dual-material object (i.e., representing a target and clutter) with stochastic thickness, where the threat material has a fixed thickness. We find for the threat class composed of a dual-material object that a minimum threat thickness of 4.5 cm is needed to achieve a desired TSI ≥ 0.7 using a joint absorption and diffraction measurement.
Original language | English (US) |
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Pages (from-to) | 1977-1992 |
Number of pages | 16 |
Journal | Applied optics |
Volume | 57 |
Issue number | 9 |
DOIs | |
State | Published - Mar 20 2018 |
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Engineering (miscellaneous)
- Electrical and Electronic Engineering