Algorithms based on time-series analysis techniques were explored for maximizing the effectiveness of pass-through radiation portal monitors for detection of special nuclear material (SNM). Time-series properties of vehicle count profiles such as stationarity and autocorrelation within energy windows were characterized. Vehicle count profiles were nonstationary but were found to be made stationary by first-differencing. Autocorrelation functions showed consistent differences between NORM alarm and non-alarm vehicles. Injection studies were performed to assess the performance of time-domain detection algorithms based on stationarity tests and on the CUSUM change-point detection test. Results indicated possible roles for detection algorithms based on statistical process control and on time series concepts.
Revised: November 15, 2007 |
Published: May 1, 2007
Citation
Lopresti C.A., B.D. Milbrath, M.F. Tardiff, and S.A. Hartley-McBride. 2007.Results from Application of Time Series Concepts to Vehicle Gamma Count Profiles. In 2007 IEEE Conference on Technologies for Homeland Security: Enhancing Critical Infrastructure, 133-138. New York, New York:Institute of Electrical and Electronics Engineers, Inc.PNNL-SA-54342.doi:10.1109/THS.2007.370034