title: Improvements in the method of radiation anomaly detection by spectral comparison ratios.
abstract: We present a new procedure for configuring the Nuisance-rejection Spectral Comparison Ratio Anomaly Detection (N-SCRAD) method. The procedure minimizes detectable count rates of source spectra at a specified false positive rate using simulated annealing. We also present a new method for correcting the estimates of background variability used in N-SCRAD to current conditions of the total count rate. The correction lowers detection thresholds for a specified false positive rate, enabling greater sensitivity to targets.
authors.affiliation: Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 USA. Electronic address: david.pfund@pnnl.gov.
authors.forename: D M
authors.initials: DM
authors.lastname: Pfund
authors.affiliation: Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 USA.
authors.forename: K K
authors.initials: KK
authors.lastname: Anderson
authors.affiliation: Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 USA.
authors.forename: R S
authors.initials: RS
authors.lastname: Detwiler
authors.affiliation: Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 USA.
authors.forename: K D
authors.initials: KD
authors.lastname: Jarman
authors.affiliation: Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 USA.
authors.forename: B S
authors.initials: BS
authors.lastname: McDonald
authors.affiliation: Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 USA.
authors.forename: B D
authors.initials: BD
authors.lastname: Milbrath
authors.affiliation: Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Myjak
authors.affiliation: U.S. Navy Space and Naval Warfare Systems Command, 53560 Hull Street, San Diego, CA 92152 USA.
authors.forename: N C
authors.initials: NC
authors.lastname: Paradis
authors.affiliation: Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Robinson
authors.affiliation: Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Woodring
keywords: Anomaly detection; Gamma-ray spectroscopy; Radiation monitoring