Detection and positioning of radioactive sources using a four-detector response algorithm

A method for detecting and identifying radioactive gamma-ray sources along with determining a directional bearing is described. This method is based upon comparing the relative intensities of four detectors placed side by side in a four-quadrant formation, allowing for the system to take advantage of shadowing in the occluded array of detectors. Based on this shielding principle, a fuzzy logic algorithm is used to analyze the gross count response of each individual detector with respect to the other three. The result of this algorithm is a numerical result that can be converted to a directional bearing in a 360° x–y plane.