Optically tracked projectile

Abstract

A projectile, that can be tracked by optical means, is fitted with a special tracer incorporated into the projectile's trailing edge. The rearward facing special tracer is incorporated into a metal disk which is crimped to the projectile's metal jacket. The special tracer includes micro-prismatic features that reflect light at the incidence angle. Alternatively, the disk incorporates a fluorescent dye that is responsive to a laser emission. External emitted radiation is reflected or re-emitted from the trailing edge of the projectile, allowing for an external electro-optic tracking device to identify the position of the projectile in flight.

What is claimed is: 
     
         1 . An ammunition projectile configured to be fired from a weapon, said projectile having an elongated circular body with side and rear surfaces and a photo-luminescent material, disposed on the rear surface, that re-emits radiation when excited by incoming radiation from a radiation source. 
     
     
         2 . The ammunition projectile defined in  claim 1 , wherein said photo-luminescent material is additionally disposed on a side surface of the projectile body. 
     
     
         3 . The ammunition projectile defined in  claim 1 , wherein said photo-luminescent material is a fluorescent dye. 
     
     
         4 . The ammunition projectile defined in  claim 3 , wherein said fluorescent dye responds to excitation in one of the UV, visual and IR spectral bands. 
     
     
         5 . The ammunition projectile defined in  claim 3 , wherein said fluorescent dye responds preferentially to the laser light illumination in a narrow frequency range. 
     
     
         6 . The ammunition projectile defined in  claim 3 , wherein the fluorescent dye forms a coating on the projectile body. 
     
     
         7 . The ammunition projectile defined in  claim 3 , wherein said projectile includes a protective ablative material disposed on the projectile body to protect said fluorescent dye during cartridge ignition. 
     
     
         8 . The ammunition projectile defined in  claim 7 , wherein said fluorescent dye forms a coating on an inside surface of said transparent material. 
     
     
         9 . An ammunition projectile with a full metal jacket configured to be fired from a weapon, said projectile having an elongated circular body with a rear trailing edge that incorporates a thin metal disk, said metal disk being crimped to the rear trailing edge of the projectile, said metal disk having an exterior-facing, outer metal surface fabricated from a metal that includes reflective, micro-prismatic surfaces. 
     
     
         10 . The ammunition projectile defined in  claim 9 , wherein said metal disk is fabricated from a reflective nickel alloy. 
     
     
         11 . The ammunition projectile defined in  claim 9 , wherein said metal disk is fabricated from a highly polished aluminum alloy. 
     
     
         12 . The ammunition projectile defined in  claim 9 , wherein said metal disk is coated with a reflective chrome finish. 
     
     
         13 . The ammunition projectile defined in  claim 9 , wherein said metal disk is fabricated by at least one of stamping, etching, and forming with a die that produces prismatic features. 
     
     
         14 . The ammunition projectile defined in  claim 9 , wherein the outer surface of said metal disk includes a thin metal surface layer adhering to an underlying polymer sheet with prismatic features. 
     
     
         15 . The ammunition projectile defined in  claim 9 , wherein said metal disk is crimped to the metal jacket at the rear trailing edge of the projectile. 
     
     
         16 . The ammunition projectile defined in  claim 15 , wherein said metal disk is optimized for rearward reflectance of reflected light over a flight path of the projectile. 
     
     
         17 . A cartridge munition comprising, in combination:
 a cartridge shell having a base;   a projectile having a rear portion inserted into the shell and mechanically connected thereto, thereby forming a propulsion chamber within the shell, said projectile having a full metal jacket;   a pyrotechnic propulsive charge disposed within the propulsion chamber; and   a pyrotechnic igniter disposed in the base of the shell by means of which the propulsive charge may be ignited such that propulsive gases of the propulsive charge exert a force on the rear of the projectile when they burn, causing the projectile to be driven out of the cartridge shell when the munition is chambered in a gun,   wherein the projectile has an elongated circular body with a rear-facing trailing surface, adjacent the propellant, that incorporates a retro-reflector.   
     
     
         18 . The cartridge munition of  claim 17 , wherein the pyrotechnic propulsive charge comprises a composition with a balanced stoichiometric combustion producing minimal combustion residue, thereby to avoid dimming the retro-reflector. 
     
     
         19 . A method of manufacturing an ammunition projectile having a retro-reflective rear surface, said method comprising the steps of:
 (a) shaping a metal jacket forming an elongated cylindrical body with a rounded nose at a front end and a trailing edge with a circular opening at a rear end, a metal jacket being formed over one or more underlying metallic materials;   (b) inserting a round disk in the circular opening, thereby fully encapsulating the formed underlying metal or metals and closing the opening, said disk having an outer surface facing rearward; and   (c) crimping the trailing edge of the metal body around the disk to form a substantially impervious seal.   
     
     
         20 . The method defined in  claim 18 , wherein the rear-facing outer surface of the disk includes reflective, micro-prismatic surfaces forming a retro-reflector. 
     
     
         21 . The method defined in  claim 18 , wherein the rear-facing outer surface of the disk is coated with a fluorescent material.