Motion correction for passive radiation imaging of small vessels in ship-to-ship inspections

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• 作者：K.P. Ziock^a ; ^{ziockk@ornl.gov" class="auth_mail" title="E-mail the corresponding author} ; C.B. Boehnen^a ; J.M. Ernst^a ; L. Fabris^a ; J.P. Hayward^a ; ^b ; T.P. Karnowski^a ; V.C. Paquit^a ; D.R. Patlolla^a ; D.G. Trombino^c
• 关键词：Position-sensitive detector ; Coded-aperture ; Gamma-ray imager ; Nuclear imaging ; Machine vision ; Vessel tracking
• 刊名：Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
• 出版年：2016
• 出版时间：1 January 2016
• 年：2016
• 卷：805
• 期：Complete
• 页码：116-126
• 全文大小：3372 K

文摘

Passive radiation detection remains one of the most acceptable means of ascertaining the presence of illicit nuclear materials. In maritime applications it is most effective against small to moderately sized vessels, where attenuation in the target vessel is of less concern. Unfortunately, imaging methods that can remove source confusion, localize a source, and avoid other systematic detection issues cannot be easily applied in ship-to-ship inspections because relative motion of the vessels blurs the results over many pixels, significantly reducing system sensitivity. This is particularly true for the smaller watercraft, where passive inspections are most valuable. We have developed a combined gamma-ray, stereo visible-light imaging system that addresses this problem. Data from the stereo imager are used to track the relative location and orientation of the target vessel in the field of view of a coded-aperture gamma-ray imager. Using this information, short-exposure gamma-ray images are projected onto the target vessel using simple tomographic back-projection techniques, revealing the location of any sources within the target. The complex autonomous tracking and image reconstruction system runs in real time on a 48-core workstation that deploys with the system.