All-optical precision gunnery simulation (PGS) method and system

Abstract

An all-optical precision gunnery simulation (PGS) system that may be adapted to simulate many tactical gunnery scenarios. The eye-safe system of this invention uses a 1550 nanometer optical infrared (IR) signal to permit increased range and field-of-view (FOV) and reduced scintillation over that of the 904 nanometer IR signals known in the art. Temporal and spatial diversity permit error-free operation over long ranges through dust and scintillation. The system performs all trajectory simulation and hit-miss assessment at the target, thereby permitting the shooter to “fire and forget” without holding station to monitor the target position. The simulation results may be reported to the shooter by passively modulating the retroreflection of an optical return window signal from the shooter. Alternatively, the target may compute shooter position from incoming optical pixel signal data for use in reporting by means of an active narrow-beam optical signal from the target back to the shooter.

I claim:  
     
         1 . A method for simulating the effects on a target of firing a ballistic projectile from a gun at a trigger pull time, the target including a retroreflector and the gun including a muzzle adapted to support an optical transmitter, the method comprising the steps of: 
 (a) illuminating the target with an optical pixel signal emitted from the optical transmitter and encoded to represent its emission angle with respect to the muzzle and global positioning system (GPS) coordinates for the gun;    (b) receiving the optical pixel signal at the target;    (c) producing target azimuth and elevation angles with respect to the gun corresponding to the optical pixel signal emission angle;    (d) producing a target range corresponding to the GPS coordinates for the gun with respect to GPS coordinates for the target; and    (e) producing a hit-miss decision representing the simulated ballistic projectile effects on the target.    
     
     
         2 . The method of  claim 1  further comprising the step of: 
 (a.1) scanning the target with a sequence of optical pixel signals each emitted from the gun at one of a plurality of predetermined emission angles.  
 
     
     
         3 . The method of  claim 2  wherein the retroreflector includes an obturator, further comprising the steps of: 
 (f) illuminating the target with an optical return window signal transmitted from the optical transmitter;  
 (g) selectively reflecting the optical return window signal back along the line of incidence by opening and closing the retroreflector obturator according to a response code representing the hit-miss decision for the simulated ballistic projectile.  
 
     
     
         4 . The method of  claim 3  further comprising the step of: 
 (e.1) producing at the target simulated projectile impact coordinates corresponding to the target azimuth and elevation angles, the target range and the trigger pull time.  
 
     
     
         5 . The method of  claim 2  further comprising the step of: 
 (a.1) encoding each optical pixel signal with a sequential beam number corresponding to a predetermined angle with respect to the muzzle.  
 
     
     
         6 . The method of  claim 1  further comprising the step of: 
 (a.1) encoding the optical pixel signal to represent the trigger pull time.  
 
     
     
         7 . The method of  claim 1  wherein the optical pixel signal is emitted at an infrared (IR) wavelength in the range from generally 1500 to generally 1600 nanometers.  
     
     
         8 . The method of  claim 2  wherein the target includes a second optical transmitter, further comprising the step of 
 (f) illuminating the gun with an optical signal emitted by the second optical transmitter and encoded to represent the hit-miss decision.  
 
     
     
         9 . The method of  claim 8  further comprising the step of: 
 (e. 1) producing at the target simulated projectile impact coordinates corresponding to the target azimuth and elevation angles, the target range and the trigger pull time.  
 
     
     
         10 . A precision gunnery simulation (PGS) transmitter assembly for use in cooperation with a PGS target assembly having a retroreflector in a PGS system for simulating the effects on a target of firing a ballistic projectile at a trigger pull time from a gun having a muzzle, the PGS transmitter assembly comprising: 
 optical transmitter means fixed to the muzzle for emitting an optical pixel signal and an optical return window signal;    transmit controller means coupled to the optical transmitter means for encoding the optical pixel signal to represent its emission angle with respect to the muzzle and global positioning system (GPS) coordinates for the gun;    optical detector means fixed to the gun for receiving a reflected optical signal from the retroreflector; and    decoder means coupled to the optical detector means for recovering data from the reflected optical signal.    
     
     
         11 . The PGS transmitter assembly of  claim 10  further comprising: 
 a scanning encoder coupled to the optical transmitter means for encoding a sequence of optical pixel signals each emitted from the gun at one of a plurality of predetermined emission angles.  
 
     
     
         12 . The PGS transmitter assembly of  claim 11  further including: 
 a beam number encoder coupled to the transmit controller means for encoding the optical pixel signal with a sequential beam number corresponding to a predetermined angle with respect to the muzzle.  
 
     
     
         13 . The PGS transmitter assembly of  claim 10  further comprising: 
 a trigger pull encoder coupled to the transmit controller means for encoding the optical pixel signals to represent the trigger pull time.  
 
     
     
         14 . The PGS transmitter assembly of  claim 10  wherein the optical transmitter means includes means for emitting infrared (IR) energy having a wavelength in the range from generally 1500 to generally 1600 nanometers.  
     
     
         15 . A precision gunnery simulation (PGS) target assembly for use in cooperation with a PGS transmitter assembly in a PGS system for simulating the effects on a target of firing a ballistic projectile at a trigger pull time from a gun having a muzzle, the PGS target assembly comprising: 
 retroreflector means for reflecting an incoming optical signal generally back along the incoming path thereof,    optical detector means for receiving an optical pixel signal encoded to represent its emission angle with respect to the muzzle and global positioning system (GPS) coordinates for the gun;    decoder means coupled to the optical detector means for producing target azimuth and elevation angles corresponding to the optical pixel signal emission angle;    ranging logic means coupled to the decoder means for producing a target range corresponding to the global positioning system (GPS) coordinates for the gun with respect to GPS coordinates for the target; and    simulation controller means coupled to the decoder means and the ranging logic means for producing a hit-miss decision representing the simulated ballistic projectile effects on the target.    
     
     
         16 . The PGS target assembly of  claim 15  further comprising: 
 an obturator disposed to selectively block reflection from the retroreflector means; and  
 an obturator modulator coupled to the obturator for selectively reflecting an optical return window signal back along the line of incidence by opening and closing the obturator.  
 
     
     
         17 . The PGS target assembly of  claim 16  further comprising: 
 an encoder coupled to the obturator modulator for encoding the reflected optical return window signal according to a response code representing the simulated ballistic projectile effects on the target.  
 
     
     
         18 . The PGS target assembly of  claim 15  further comprising: 
 in the simulation controller means, means for producing simulated projectile impact coordinates corresponding to the target azimuth and elevation angles, the target range and the trigger pull time.  
 
     
     
         19 . The PGS target assembly of  claim 15  further comprising: 
 an optical transmitter for transmitting an optical signal;  
 an encoder coupled to the optical transmitter for encoding the optical signal to represent the hit-miss decision; and  
 a steering logic coupled to the optical transmitter for aiming the optical signal to illuminate the gun location corresponding to the optical pixel signal.  
 
     
     
         20 . The PGS transmitter assembly of  claim 15  wherein the optical detector means has a field of view (FOV) of generally 360 degrees in azimuth and generally 45 degrees in elevation.  
     
     
         21 . A precision gunnery simulation (PGS) system for simulating the effects on a target of firing a ballistic projectile at a trigger pull time from a gun having a muzzle, the PGS system comprising: 
 a PGS transmitter assembly comprising 
 an optical transmitter fixed to the muzzle for emitting an optical pixel signal and an optical return window signal,  
 a transmit controller coupled to the optical transmitter for encoding the optical pixel signal to represent its emission angle with respect to the muzzle and global positioning system (GPS) coordinates for the gun,  
 a first optical detector fixed to the gun for receiving a reflected optical signal from the retroreflector, and  
 a first decoder coupled to the first optical detector for recovering data from the reflected optical signal; and  
 a PGS target assembly comprising 
 a retroreflector for reflecting an incoming optical signal generally back along the incoming path thereof,  
 a second optical detector for receiving an optical pixel signal encoded to represent its emission angle with respect to the muzzle and GPS coordinates for the gun,  
 a second decoder coupled to the second optical detector for producing target azimuth and elevation angles corresponding to the optical pixel signal emission angle,  
 a ranging logic coupled to the second decoder for producing a target range corresponding to the GPS coordinates for the gun with respect to GPS coordinates for the target, and  
 a simulation controller coupled to the second decoder and the ranging logic for producing a hit-miss decision representing the simulated ballistic projectile effects on the target.  
 
   
     
     
         22 . The PGS system of  claim 21  further comprising: 
 in the PGS transmitter assembly, a scanning encoder coupled to the optical transmitter for encoding a sequence of optical pixel signals each emitted from the gun at one of a plurality of predetermined emission angles.  
 
     
     
         23 . The PGS transmitter assembly of  claim 22  further including: 
 in the PGS transmitter assembly, a beam number encoder coupled to the transmit controller for encoding the optical pixel signal with a sequential beam number corresponding to a predetermined angle with respect to the muzzle.  
 
     
     
         24 . The PGS transmitter assembly of  claim 21  further including: 
 in the PGS transmitter assembly, a trigger pull encoder coupled to the transmit controller for encoding the optical pixel signals to represent the trigger pull time.  
 
     
     
         25 . The PGS system of  claim 21  wherein the optical transmitter emits infrared (IR) energy having a wavelength in the range from generally 1500 to generally 1600 nanometers.  
     
     
         26 . The PGS system of  claim 21  further comprising: 
 in the PGS target assembly, 
 an obturator disposed for obstructing the retroreflector to prevent reflection thereby; and  
 a controller coupled to the retroreflector obturator for selectively reflecting an optical return window signal back along the line of incidence by opening and closing the retroreflector obturator.  
 
 
     
     
         27 . The PGS system of  claim 26  further comprising: 
 in the PGS target assembly, an encoder coupled to the controller for encoding the reflected optical return window signal according to a response code representing the simulated ballistic projectile effects on the target.  
 
     
     
         28 . The PGS system of  claim 21  further comprising: 
 in the PGS target assembly simulation controller, logic for producing simulated projectile impact coordinates corresponding to the target azimuth and elevation angles, the target range and the trigger pull time.  
 
     
     
         29 . The PGS target assembly of  claim 21  further comprising: 
 in the PGS target assembly, 
 an optical transmitter for transmitting an optical signal;  
 an encoder coupled to the optical transmitter for encoding the optical signal to represent the hit-miss decision; and  
 a steering logic coupled to the optical transmitter for aiming the optical signal to illuminate the gun location corresponding to the optical pixel signal.  
 
 
     
     
         30 . The PGS system of  claim 21  wherein the second optical detector has a field of view (FOV) of generally 360 degrees in azimuth and generally 45 degrees in elevation.