Gun muzzle reference system

Abstract

A muzzle reference system is provided for correcting errors in aiming signals produced by a fire-control system of an artillery gun having a gun muzzle pivotable about a first axis and movable about a second axis extending perpendicularly of the first axis. A laser beam transmitting unit adapted to be mounted on the gun for movement with the barrel about the second axis, directs a laser beam along an optical axis in response to an activating signal. A reflection unit, adapted to be mounted at the distal end of the barrel, reflects a laser beam received from the transmitting unit along the optical axis substantially along a reference optical axis at a predetermined angular position of the barrel about the first axis. A laser beam receiving unit, adapted to be mounted on the gun, receives a laser beam reflected substantially along the reference optical axis and produces signals representative of the deviation of the reflected beam from the perdetermined optical axis. A processing unit connected to the receiving unit and adapted to be connected to the fire-control system converts the deviation representative signals to aiming correction signals and adds the latter to the aiming signals. Monitoring means monitors the position of the barrel about the first axis and applies the activating signal to the transmitting unit when the barrel is at its predetermined position.