Information driven localisation of a radiological point source

The paper presents an algorithm for detection and a subsequent information gain driven control of the observer for the purpose of parameter estimation of an unaccounted point source of relatively low-level gamma radiation. The source parameters to be estimated are its location and intensity. Source detection and parameter estimation are carried out jointly in the Bayesian framework using a particle filter. The observer motion and the radiation exposure time are controlled by the algorithm. Initially the observer control vectors take predefined values until the source is positively detected. After detection, the control vectors are selected sequentially for the purpose of reduction in the observation time and consequently the radiation exposure. The selection of control vectors is carried out via a multiple-step ahead maximisation of the Fisher information gain.