Abstract: A method of operation for a motor vehicle object detection system is described, in which the extent angle of an identified target is accurately determined by applying a point source scatterer identification technique to data at the periphery of a composite return. Return amplitude data from one or more complete scans of the sensor beam are collected and compared with a target threshold to identify objects in the viewing angle, thereby forming an array of amplitude data associated with successive beam positions for each identified object. In each array, the left-most and right-most pair of amplitude data points associated with successive beam positions are selected and individually used to compute the angle of a point source scatterer which would be responsible for that data pair.