The present disclosure describes a method and system for detecting and determining the position of a target or intruder using a plurality of sensors positioned throughout a secured perimeter and a single antenna. The system of the present disclosure detects and determines the position of a target by first analyzing the return signal strength values of each of the sensors. Next, Zvalues for each of the sensors are calculated. Based on the Zvalues, certain sensors are selected to compute a signal strength center-of-mass location, which is then used to determine the position of the target.