Source localisation results based on Bayesian inference applied to event-by-event data. Each panel corresponds to a 10 s measurement of the 1.25 μCi Cf-252 source placed at (x, y, z)=(0, 0, 52) cm. The deduced projected probability density distributions in the y − z plane are shown for the bare source (left), inside the PE1000 shielding (middle), and inside the lead shielding (right). The calculated probability of finding the source per cm² pixel is indicated by the colour scale on the right. Taken from reference [29].