Abstract: A method for discriminating a radioactive anomaly from naturally occurring radioactive materials includes detecting a first number of gamma photons having energies in a first range of energy values within a predetermined period of time and detecting a second number of gamma photons having energies in a second range of energy values within the predetermined period of time. The method further includes determining, in a controller, a ratio of the first number of gamma photons having energies in the first range and the second number of gamma photons having energies in the second range, and determining that a radioactive anomaly is present when the ratio exceeds a threshold value.

Abstract: A method for discriminating a radioactive anomaly from naturally occurring radioactive materials includes detecting a first number of gamma photons having energies in a first range of energy values within a predetermined period of time and detecting a second number of gamma photons having energies in a second range of energy values within the predetermined period of time. The method further includes determining, in a controller, a ratio of the first number of gamma photons having energies in the first range and the second number of gamma photons having energies in the second range, and determining that a radioactive anomaly is present when the ratio exceeds a threshold value.

Abstract: Embodiments of the invention pertain to a method and apparatus for spectral deconvolution of detector spectra. In a specific embodiment, the method can be applied to sodium iodide scintillation detector spectra. An adaptive chi-processed (ACHIP) denoising technique can be used to remove the results of stochastic noise from low-count detector spectra. Embodiments of the ACHIP denoising algorithm can be used as a stand alone tool for rapid processing of one dimensional data with a Poisson noise component. In a specific embodiment, the denoising technique can be combined with the spectral deconvolution method. Embodiments of the denoising technique and embodiments of the deconvolution method can be applied to any detector material that provides a radiation spectrum. Specific embodiments can incorporate one or more of the following for spectral deconvolution: denoising, background subtraction, detector response function generation, and subtraction of detector response functions.