Projectile position detection apparatus

Disclosed is an apparatus for indicating the location in a measurement plane through which a projectile passes. The apparatus includes an array of at least three transducers responsive to the airborne pressure wave produced by the projectile and positioned at predetermined locations along a line parallel to the movement plane. The apparatus further includes a device for measuring the velocity of the projectile and another for measuring the velocity of sound in air in the vicinity of the transducers. A computing means, responsive to the array of transducers, the velocity measuring means and the propagation of sound determination is provided which determines the location in the measurement plane through which the projectile passed and provides an output indicating that location. Also disclosed is a means, in combination with the position detecting means, for detecting and providing a positive indication of a projectile hit on a target member.