1. A method for locating a radio frequency emitter that transmits pulses in a swept beam pattern comprising the steps of: storing intervisibility data of terrain points in a region around an observation point; measuring at the observation point the times of arrival of a plurality of terrain point reflections of a single pulse transmitted by the emitter; repeating the measuring step for a plurality of pulses transmitted by the emitter; and comparing terrain points of reflection calculated from the measured times of arrival for assumed emitter locations with the stored intervisibility data of terrain points.