US Patent 7765083 Method and apparatus for detecting sources of projectiles

What is provided is the use of an array of E-field sensors to detect the closest approach of incoming projectiles and to determine through time difference of arrival the bearing of the incoming projectile, thus to identify the bearing of the source of the projectile. dE/dT processing of the individual outputs of the E-field sensors indicates by the zero crossing the peak of the E-field disturbance and thus the instance of time of the closest approach of the projectiles to a sensor.