Digital Position Estimation for the Modular Scintillation Camera

Digital implementation of position estimation for the modular scintillation camera is presented. The modular camera system, introduced at the 1983 IEEE Nuclear Science Symposium, comprises an array of small, mechanically and electronically independent, all-digital scintillation cameras. This paper addresses how to best determine the event position given the PMT signals. Two Bayesian estimators are investigated, namely maximum-likelihood (ML) and minimum-meansquare-error (MS) estimators. Both estimators performed similarly. The more important aspect of the estimation problem was found to be the shape of the detector responses as a function of position.