title: A deviation display method for visualising data in mobile gamma-ray spectrometry.
abstract: A real time visualisation method, to be used in mobile gamma-spectrometric search operations using standard detector systems is presented. The new method, called deviation display, uses a modified waterfall display to present relative changes in spectral data over energy and time. Using unshielded (137)Cs and (241)Am point sources and different natural background environments, the behaviour of the deviation displays is demonstrated and analysed for two standard detector types (NaI(Tl) and HPGe). The deviation display enhances positive significant changes while suppressing the natural background fluctuations. After an initialization time of about 10min this technique leads to a homogeneous display dominated by the background colour, where even small changes in spectral data are easy to discover. As this paper shows, the deviation display method works well for all tested gamma energies and natural background radiation levels and with both tested detector systems.
authors.affiliation: Department of Medical Radiation Physics, Clinical Sciences, Lund University, University Hospital, Lund, Sweden. Peder.Kock@med.lu.se
authors.forename: Peder
authors.initials: P
authors.lastname: Kock
authors.forename: Robert R
authors.initials: RR
authors.lastname: Finck
authors.forename: Jonas M C
authors.initials: JM
authors.lastname: Nilsson
authors.forename: Karl
authors.initials: K
authors.lastname: Ostlund
authors.forename: Christer
authors.initials: C
authors.lastname: Samuelsson
mesh_terms: D003626:Data Display; D004867:Equipment Design; D019544:Equipment Failure Analysis; D011868:Radioisotopes / Q000032:analysis*; D013051:Spectrometry, Gamma / Q000295:instrumentation*; D014584:User-Computer Interface
chemical_list: D011868:Radioisotopes