Patent ID: 7022998

Claim:
A method for determining dose or dose rate for one or more selected locations within an environment, comprising the steps of: a) measuring incident gamma ray energy and count rate from one or more sources, for one or more viewed portions of the environment, at one or more measured locations within the environment to obtain one or more measured spectra for said measured locations; b) measuring the spatial position of each of said measured locations; c) determining an emitted spectrum for each said viewed portion of the environment from said measured spectrum for each said viewed portion of the environment; d) inputting the emitted spectra and said spatial position of said measured locations to data processor; and e) determining the dose or dose rate at one or more selected locations from a calculated total gamma ray energy incident on the one or more selected locations arising from the emitted spectrum of the one or more sources, wherein the measured spectra is divided into a series of energy ranges or bins, the count rates or counts falling within a range or bin are summed to give a total count rate or total count for that range or bin, the series of energy ranges or bins including a highest energy range or bin, where the highest energy range or bin is analyzed first, the analysis involving subtracting from the ranged or binned spectrum a value, the value being based on a response function multiplied by a variable factor to reduce the range or bin under analysis to zero.