Title:
Precision zeroed small-arms transmitter (ZSAT) with shooter sight-picture compensation capability
Kind Code:
A1


Abstract:
A system for precisely calibrating the misalignment of a weapon-mounted zeroed small arms transmitter (ZSAT) laser beam axis with the shooter line-of-sight (LOS) to a target in a weapon training system. When a blank cartridge is fired through a blank fire adapter (BFA) affixed to the weapon muzzle in a predetermined disposition, the dynamic muzzle displacement during the first milliseconds may be characterized as a two-dimensional shooter-independent “signature” representative of the BFA disposition, the blank cartridge and the weapon. The misalignment of the ZSAT laser beam axis with the shooter LOS is calibrated by transmitting a sequence of optical pixel signals during an early portion of the dynamic muzzle displacement interval to paint a target. A shooter LOS offset is deduced from the number of pixel signals illuminating the target and stored to compensate for any misalignment of the ZSAT laser beam axis with the shooter LOS during later use.



Inventors:
Varshneya, Deepak (Del Mar, CA, US)
Schroder, Bart (Auckland, NZ)
Application Number:
10/189090
Publication Date:
01/08/2004
Filing Date:
07/03/2002
Assignee:
VARSHNEYA DEEPAK
SCHRODER BART
Primary Class:
Other Classes:
434/22, 434/16
International Classes:
F41G1/54; (IPC1-7): F41A33/00
View Patent Images:



Primary Examiner:
SAADAT, CAMERON
Attorney, Agent or Firm:
Kilpatrick Townsend & Stockton LLP - West Coast (Atlanta, GA, US)
Claims:

We claim:



1. In a weapon training system for simulating the use of a weapon against a target by a shooter having a line-of-sight (LOS) to the target, the system including a retroreflector adapted to be secured to the target for reflecting an incident optical signal back along the line of incidence, and a small-arms transmitter (SAT) assembly having a laser beam axis and adapted to be secured to the weapon, a method for calibrating a misalignment of the laser beam axis with the shooter LOS, comprising the steps of: (a) aligning the shooter LOS with the retroreflector; (b) triggering the weapon to fire a blank cartridge; (c) transmitting a sequence of optical pixel signals along the laser beam axis responsive to the weapon triggering step (b); (d) detecting one or more optical pixel signals reflected from the retroreflector; and (e) storing a shooter LOS offset corresponding to the reflected optical pixel signals detected.

2. The calibrating method of claim 1 further comprising the step of: (c.1) encoding each of the optical pixel signals as a beam number.

3. The calibrating method of claim 2 wherein the weapon training system includes a blank fire adaptor (BFA) adapted to be secured to the weapon, further comprising the steps of: (a.1) securing the BFA to the weapon in a predetermined disposition; and (c.2) configuring the sequence of optical pixel signals according to a signature corresponding to the predetermined BFA disposition.

4. The calibrating method of claim 1 further comprising the steps of: (f) repeating the steps (a) through (d); and (g) revising the shooter LOS offset according to the reflected optical pixel signals detected.

5. In a weapon training system for simulating the use of a weapon against a target by a shooter having a line-of-sight (LOS) to the target, the system including a first optical detector adapted to be secured to the target for receiving an incident optical signal, and a small-arms transmitter (SAT) assembly having a laser beam axis and adapted to be secured to the weapon, a method for calibrating a misalignment of the laser beam axis with the shooter LOS, comprising the steps of: (a) aligning the shooter LOS with the optical detector; (b) triggering the weapon to fire a blank cartridge; (c) transmitting a sequence of optical pixel signals along the laser beam axis responsive to the triggering step (b); (d) detecting one or more optical pixel signals received at the first optical detector; and (e) storing a shooter LOS offset corresponding to the optical pixel signals detected.

6. The calibrating method of claim 5 further comprising the step of: (c.1) encoding each of the optical pixel signals as a beam number.

7. The calibrating method of claim 6 wherein the weapon training system includes a second optical detector adapted to be secured to the target for receiving an incident optical signal and for cooperating with the first optical detector to form an optical detector array, the method further comprising the steps of: (d.1) detecting the optical pixel signals received at the second optical detector; and (e.1) storing a two-dimensional shooter LOS offset corresponding to the optical pixel signals detected

8. The calibrating method of claim 7 further comprising the step of: (e.2) transmitting to the SAT assembly a signal representing the two-dimensional shooter LOS offset.

9. The calibrating method of claim 6 wherein the weapon training system includes a blank fire adaptor (BFA) adapted to be secured to the weapon, further comprising the steps of: (a.1) securing the BFA to the weapon in a disposition; and (c.2) configuring the sequence of optical pixel signals according to a signature corresponding to the predetermined BFA disposition.

10. The calibrating method of claim 5 further comprising the steps of: (f) repeating the steps (a) through (d); and (g) revising the shooter LOS offset according to the reflected optical pixel signals detected.

11. The calibrating method of claim 5 further comprising the steps of: (e.1) transmitting to the SAT assembly a signal representing the shooter LOS offset.

12. A weapon training system for simulating the use of a weapon against a target by a shooter having a line-of-sight (LOS) to the target, the system comprising: a retroreflector adapted to be secured to the target for reflecting an incident optical signal back along the line of incidence; and a small-arms transmitter (SAT) assembly having a laser beam axis and adapted to be secured to the weapon, including an optical transmitter, an optical detector for receiving optical pixel signals from the retroreflector, and a sight-picture compensator for calibrating the misalignment of the laser beam axis with the shooter LOS, including a controller coupled to the optical transmitter for producing an optical pixel signal sequence responsive to the triggering of the weapon, and a data store coupled to the optical detector for storing a shooter LOS offset corresponding to the reflected optical pixel signals detected.

13. The weapon training system of claim 12 further comprising: an encoder coupled to the controller for encoding each of the optical pixel signals as a beam number.

14. The weapon training system of claim 13 wherein the encoder is coupled to the data store and includes means for encoding each of the sequence of optical pixel signals according to the shooter LOS offset.

15. The weapon training system of claim 13 further comprising: a blank fire adaptor (BFA) adapted to be secured to the weapon, wherein the sequence of optical pixel signals is encoded according to a signature corresponding to a predetermined BFA disposition on the weapon.

16. The weapon training system of claim 12 wherein the optical transmitter comprises: an infrared laser adapted to generate an optical signal in the range from generally 800 nanometers to generally 10,600 nanometers.

17. A weapon training system for simulating the use of a weapon against a target by a shooter having a line-of-sight (LOS) to the target, the system comprising: a first optical detector adapted to be secured to the target for receiving an incident optical pixel signal; a small-arms transmitter (SAT) assembly having a laser beam axis and adapted to be secured to the weapon, including an optical transmitter, and a sight-picture compensator for offsetting the misalignment of the laser beam axis with the shooter LOS to the target, including a controller coupled to the optical transmitter for producing an optical pixel signal sequence responsive to the triggering of the weapon, and a data store coupled to the controller for storing a shooter LOS offset corresponding to the optical pixel signals detected.

18. The weapon training system of claim 17 further comprising: an encoder coupled to the controller for encoding each of the optical pixel signals as a beam number.

19. The weapon training system of claim 18 further comprising: a blank fire adaptor (BFA) adapted to be secured to the weapon, wherein the sequence of optical pixel signals is encoded according to a signature corresponding to a predetermined BFA disposition on the weapon.

20. The weapon training system of claim 17 further comprising: a signal transmitter coupled to the optical detector for transmitting an offset signal representing the shooter LOS offset; and a signal receiver coupled to the SAT assembly for receiving the offset signal

21. The weapon training system of claim 20 wherein the encoder is coupled to the signal receiver and includes means for encoding each of the sequence of optical pixel signals according to the shooter LOS offset.

22. The weapon training system of claim 17 wherein the optical transmitter comprises: an infrared laser adapted to generate an optical signal in the range from generally 800 nanometers to generally 10,600 nanometers.

23. The weapon training system of claim 17 further comprising: a second optical detector adapted to be secured to the target for receiving an incident optical signal and for cooperating with the first optical detector to form an optical detector array; and means for storing in the data store a two-dimensional shooter LOS offset corresponding to a plurality of optical pixel signals.

24. A small-arms transmitter (SAT) assembly having a laser beam axis and adapted to be secured to a weapon for use in a weapon training system for simulating the use of the weapon against a target by a shooter having a line-of-sight (LOS) to the target, including a retroreflector secured to the target for reflecting an incident optical signal back along the line of incidence, the SAT assembly comprising: an optical transmitter; an optical detector for receiving optical pixel signals from the retroreflector; and a sight-picture compensator for calibrating the misalignment of the laser beam axis with the shooter LOS, including a controller coupled to the optical transmitter for producing an optical pixel signal sequence responsive to the triggering of the weapon, and a data store for storing a shooter LOS offset corresponding to the reflected optical pixel signals detected.

25. The SAT assembly of claim 24 further comprising: an encoder coupled to the controller for encoding each of the optical pixel signals as a beam number.

26. The SAT assembly of claim 25 wherein the encoder is coupled to the data store and includes means for encoding each of the sequence of optical pixel signals according to the shooter LOS offset.

27. The SAT assembly of claim 25 wherein a blank fire adaptor (BFA) is secured to the weapon in a predetermined disposition, the SAT assembly further comprising: means for encoding the sequence of optical pixel signals according to a signature corresponding to the predetermined BFA disposition on the weapon.

28. The SAT assembly of claim 24 wherein the optical transmitter comprises: an infrared laser adapted to generate an optical signal in the range from generally 800 nanometers to generally 10,600 nanometers.

29. A small-arms transmitter (SAT) assembly having a laser beam axis and adapted to be secured to a weapon for use in a weapon training system for simulating the use of the weapon against a target by a shooter having a line-of-sight (LOS) to the target, including a first optical detector adapted to be secured to the target for receiving an incident optical signal, the SAT assembly comprising: an optical transmitter; and a sight-picture compensator for offsetting the misalignment of the laser beam axis with the shooter LOS to the target, including a controller coupled to the optical transmitter for producing an optical pixel signal sequence responsive to the triggering of the weapon, and a data store for storing a shooter LOS offset corresponding to the optical pixel signals detected.

30. The SAT assembly of claim 29 further comprising: an encoder coupled to the controller for encoding each of the optical pixel signals as a beam number.

31. The SAT assembly of claim 30 wherein a signal transmitter is coupled to the first counter for transmitting an offset signal representing the shooter LOS offset, the SAT assembly further comprising: a signal receiver coupled to the data store for receiving the offset signal.

32. The SAT assembly of claim 31 wherein the encoder is coupled to the signal receiver and includes means for encoding each of the sequence of optical pixel signals according to the shooter LOS offset.

33. The SAT assembly of claim 30 wherein a blank fire adaptor (BFA) is secured to the weapon in a predetermined disposition, the SAT assembly further comprising: means for encoding the sequence of optical pixel signals according to a signature corresponding to the predetermined BFA disposition on the weapon.

34. The SAT assembly of claim 29 wherein the optical transmitter comprises: an infrared laser adapted to generate an optical signal in the range from generally 800 nanometers to generally 10,600 nanometers.

35. The SAT assembly of claim 29 wherein a second optical detector is secured to the target for receiving an incident optical signal and for cooperating with the first optical detector to form an optical detector array, the SAT assembly further comprising: means for storing in the data store a two-dimensional shooter LOS offset corresponding to a plurality of optical pixel signals.

36. The SAT assembly of claim 29 a signal transmitter is coupled to the data store for transmitting an offset signal representing the shooter LOS offset, the SAT assembly further comprising: a signal receiver for receiving the offset signal.

37. In a weapon training system for simulating the use of a weapon against a target by a shooter having a line-of-sight (LOS) to the target, the system including a retroreflector adapted to be secured to the target for reflecting an incident optical signal back along the line of incidence, and a small-arms transmitter (SAT) assembly having a laser beam axis and adapted to be secured to the weapon, a method for precisely locating a simulated hit point on the target, comprising the steps of: (a) aligning the shooter LOS with the retroreflector; (b) triggering the weapon to fire a blank cartridge; (c) transmitting a sequence of optical pixel signals along the laser beam axis responsive to the weapon triggering step (b); (d) detecting one or more optical pixel signals reflected from the retroreflector; and (e) determining the simulated hit point corresponding to the reflected optical pixel signals detected.

38. The calibrating method of claim 37 further comprising the step of: (c.1) encoding each of the optical pixel signals as a beam number.

39. A weapon training system for simulating the use of a weapon against a target by a shooter having a line-of-sight (LOS) to the target, the system comprising: a retroreflector adapted to be secured to the target for reflecting an incident optical signal back along the line of incidence; and a small-arms transmitter (SAT) assembly having a laser beam axis and adapted to be secured to the weapon, including an optical transmitter, an optical detector for receiving an optical pixel signal from the retroreflector, and a precision hit-point localizer for precisely locating a simulated hit point on the target, including a controller coupled to the optical transmitter for producing an optical pixel signal sequence responsive to the triggering of the weapon, and a logic coupled to the optical detector for determining the simulated hit point corresponding to the reflected optical pixel signals detected.

40. The weapon training system of claim 39 further comprising: an encoder coupled to the controller for encoding each of the optical pixel signals as a beam number.

41. In a weapon training system for simulating the use of a weapon against a target by a shooter having a line-of-sight (LOS) to the target, the system including a first optical detector adapted to be secured to the target for receiving an incident optical signal, and a small-arms transmitter (SAT) assembly having a laser beam axis and adapted to be secured to the weapon, a method for precisely locating a simulated hit point on the target, comprising the steps of: (a) aligning the shooter LOS with the optical detector; (b) triggering the weapon to fire a blank cartridge; (c) transmitting a sequence of optical pixel signals along the laser beam axis responsive to the triggering step (b); (d) detecting one or more optical pixel signals received at the first optical detector; and (e) determining the simulated hit point corresponding to the number of optical pixel signals detected.

42. The calibrating method of claim 41 further comprising the step of: (c.1) encoding each of the optical pixel signals as a beam number.

43. The calibrating method of claim 41 wherein the weapon training system includes a second optical detector adapted to be secured to the target for receiving an incident optical signal and for cooperating with the first optical detector to form an optical detector array, the method further comprising the steps of: (d.1) detecting one or more optical pixel signals received at the second optical detector; and (e.1) determining the simulated hit point corresponding to a plurality of the optical pixel signals detected.

44. A weapon training system for simulating the use of a weapon against a target by a shooter having a line-of-sight (LOS) to the target, the system comprising: a first optical detector adapted to be secured to the target for receiving an incident optical signal; and a small-arms transmitter (SAT) assembly having a laser beam axis and adapted to be secured to the weapon, including an optical transmitter, and a sight-picture compensator for offsetting the misalignment of the laser beam axis with the shooter LOS to the target, including a controller coupled to the optical transmitter for producing a optical pixel signal sequence responsive to the triggering of the weapon, and a data store coupled to the controller for storing a shooter LOS offset corresponding to the optical pixel signals detected.

45. The weapon training system of claim 44 further comprising: an encoder coupled to the controller for encoding each of the optical pixel signals as a beam number.

46. The weapon training system of claim 44 further comprising: a second optical detector adapted to be secured to the target for receiving an incident optical signal and for cooperating with the first optical detector to form an optical detector array; and means for determining the simulated hit point corresponding to a plurality of the optical pixel signal count detected.

47. In a Multiple Integrated Laser Engagement System (MIES) system for simulating the use of a weapon against a target by a shooter having a line-of-sight (LOS) to the target, the system including a MILES target vest and a small-arms transmitter (SAT) assembly adapted to be secured to the weapon and having a laser beam axis and means for storing a shooter LOS offset, a method for compensating a misalignment of the laser beam axis with the shooter LOS, comprising the steps of: (a) aligning the shooter LOS with the target vest; (b) triggering the weapon; (c) transmitting a sequence of MILES optical codes along the laser beam axis responsive to the weapon triggering step (b), wherein each MILES optical code is delayed with respect to the triggering step (b) according to the stored shooter LOS offset.

Description:

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application is related by common inventorship and subject matter to the commonly-assigned U.S. Pat. No. 6,406,298 entitled “Low Cost Laser Small Arms Transmitter And Method of Aligning The Same,” which is entirely incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates generally to military training equipment and more particularly to a zeroed small arms transmitter (ZSAT) assembly with a self-aligning sight-picture compensator for offsetting the misalignment of the ZSAT laser beam axis with the shooter line-of-sight (LOS) to the target.

[0004] 2. Description of the Related Art

[0005] The Multiple Integrated Laser Engagement System (MILES 2000®) produced by Cubic Defense Systems, Inc., exemplifies a modern realistic force-on-force training system. As a standard for direct-fire tactical engagement simulation, MILES 2000 is a system employed for training soldiers by the U.S. Army, Marine Corps and Air Force and international forces such as the Royal Netherlands Marine Corps, Kuwait Land Forces and the UK Ministry of Defence.

[0006] MILES 2000 components include wearable systems for individual soldiers and marines as well as interface devices for combat vehicles (including pyrotechnic devices), personnel carriers, antitank weapons, and pop-up and stand-alone targets The MILES 2000 laser-based system allows troops to fire infrared “bullets” from the same weapons and vehicles that they would use in actual combat. These simulated direct-fire events produce realistic audio/visual effects and casualties, identified as a “hit,” “miss” or “kill.” The events are then recorded, replayed and analyzed in detail during After Action Reviews, which give commanders and participants an opportunity to review their performance during the training exercise. Unique player ID codes and Global Positioning System (GPS) technology ensure accurate data collection, including casualty assessments and participant positioning.

[0007] The MILES 2000 individual weapons system includes small, lightweight components mounted on either a vest or H-harness; and a Small Arms Transmitter (SAT) mounted on the soldier's individual weapon or machine gun, which may be appreciated with reference to the commonly-assigned U.S. Pat. No. 5,475,385 issued to Parikh et al. and incorporated herein by reference. Realism is enhanced by employing light wearable equipment that is nearly transparent to the user, particularly the H-harness or vest that may be worn over other combat equipment. The system replicates the ranges and lethality of the soldier's individual weapon or machine gun while holding shooter alignment during blank fire; thereby training the shooter under conditions identical to actual combat weapons operation. Thus, among other demanding technical requirements, MILES 2000 requires the SAT laser beam axis to be properly aligned with the line of sight (LOS) axis of the weapon to ensure its range effectiveness.

[0008] Disadvantageously, simply aligning the laser beam axis with the weapon LOS is not sufficient for realistic training because the optical beam travels instantly to the target in a straight line, which does not represent the parabolic trajectory of a live projectile fired from the same weapon by the same shooter under the same circumstances. The parabolic trajectory is aligned with the weapon sights during a formal iron-sight alignment (“zeroing”) procedure, which is in the U.S. generally required semi-annually by the military forces for each weapon. This procedure is performed at a shooting range with live ammunition by the shooter to whom the weapon is assigned. During the typical weapon zeroing procedure, the shooter aligns the “iron” sights of the assigned weapon so that 70-80% of the shots strike targets at 25 meters (and 300 meters) distance when the shooter line-of-sight (LOS) is on-target. After firing, the location of the cluster of bullet holes in the target is observed and corresponding azimuth and elevation adjustments are made to the conventional “iron” sights of the weapon. Live ammunition is again fired and the process iterated until satisfactory results obtain. A record is made of the sight adjustments and attached to the weapon for use in resetting a disturbed adjustment. The conventional sights of the M16A2 rifle may be adjusted to achieve a 95% kill ratio at both 25 and 300 meters because the bullet trajectory is a flat parabola that rises to the bulls-eye at 25 meters, continues rising to a peak, and falls to the bulls-eye at 300 meters, provided that the bulls-eyes are collinear with the shooter LOS. Disadvantageously, this formal zeroing procedure requires access to a live ammunition facility after the boresighting procedure has aligned the weapon boresight to the shooter LOS.

[0009] The SAT to LOS alignment problem is well-known in the art and solutions have been proposed by other practitioners. For example, the present state of the art may be appreciated with reference to the commonly-assigned U.S. Pat. No. 5,410,815 issued to Parikh et al. and incorporated herein by reference. Parikh et al. describe an alignment system that requires the weapon-mounted SAT to be clamped in an Automatic Small Arms Alignment Fixture (ASAAF) after the shooter aims the weapon along a LOS to a target. Once clamped in the position for which the shooter LOS is aligned with the target, the ASAAF iteratively triggers the SAT and mechanically rotates two optical wedges in the SAT laser beam axis to orient the optical beam until it is aligned along an axis coincident with the LOS at the target. Disadvantageously, this approach requires many additional moving mechanical and optical parts that increase the SAT cost and complexity and reduce its reliability. Moreover, this is a time-consuming procedure requiring the ASAAF to be shared among forty or more soldiers and the procedure may not always be performed because it is not formally required as part of true combat doctrine. Advantageously, alignment of the SAT laser beam with the shooter LOS instead of the weapon boresight avoids any requirement for zeroing the weapon with live ammunition during training. The SAT to LOS alignment is also customized for the individual weapon and shooter, so long as the weapon-mounted SAT retains its mechanical alignment and the weapon remains with the shooter for whom it was aligned.

[0010] But the LOS is unique to the shooter. This is because each shooter aligns the iron sights in a fashion that is subtly unique to the individual shooter, who may view the target “sight picture” along a LOS described by the iron-sight elements in a subtly different manner from the LOS sighted by another shooter. Although the shooter may be permitted to keep a personally-zeroed weapon, if the weapon is assigned to another shooter during training, it must be again zeroed by the new shooter because effective training of the shooter requires the SAT assembly laser beam to be aligned with the particular LOS that the new shooter actually aligns with the target, herein denominated the “shooter sight picture.” There are many nations where the same weapon is shared among several “citizen” soldiers during training. Unless the weapon can be zeroed by the new shooter in a live-fire facility, the only way to provide the proper training experience is to somehow compensate for the difference in sight-pictures between the original and new shooters, herein denominated “sight-picture compensation.”

[0011] Other practitioners have proposed systems that provide useful automatic alignment compensation for military small arms training purposes. For example, in U.S. Pat. No. 4,781,593, Birge et al. describe a laser weapon simulator that requires a gunner to correctly lead a moving target when using a laser direct fire weapon simulator for markmanship training. The weapon simulator includes one or more lasers for firing a plurality of radiation beams along the weapon boresight and on one or both sides thereof An encoding circuit assigns a code to each radiation beam and a simulated target has a radiation detector for detecting the radiation beams of the lasers and includes a decoder for recognizing each code assigned to each radiation beam and comparing the lead taken by the gunner with the required lead. But Birge et al neither consider nor suggest a solution to the sight picture compensation problem discussed above.

[0012] In another example, U.S. Pat. No. 4,959,016 issued to Lawrence describes a weapon simulator for simulating small arms that includes a laser projector for attachment to the weapon. Firing the weapon initiates the production of a narrow, pulsed, beam by the laser, and this beam is scanned vertically downwardly while its pulse repetition frequency is varied as a function of vertical scan angle. The beam is received by a spatially diverse pair of detectors on the target. One detector effectively determines the width of the beam, thus permitting the range from the weapon to the target to be computed from the beam width and the change in the pulse repetition frequency detected from the start to the finish of the first detector illumination. The elevation angle of the weapon with respect to the target is computed from the mean pulse repetition frequency detected by a second detector. Finally, the accuracy of aim of the weapon (i.e. whether the firing resulted in a hit or a miss) is determined from a combination of the range, the weapon elevation angle, and the weapon/ammunition type. But Lawrence neither considers nor suggests a solution to the sight picture compensation problem discussed above.

[0013] The above-cited U.S. Pat. No. 6,406,298 discloses a low-cost SAT that includes a hollow housing for the laser diode, the rear segment of which may be permanently bent to align the laser beam with the boresight of the weapon. This advantageously permits boresight alignment of the SAT without complex optical wedges and equipment and, if the weapon is also zeroed at 25 meters, the laser beam is then aligned with the shooter LOS without any sight-picture compensation. But any changes in target distance from the 25/300 meter standards (for example, to 75 meters) or any change in shooter introduces misalignment of the SAT laser beam and shooter LOS in the weapon. This requires some form of sight-picture compensation in the field to provide an effective training experience to the shooter. Nothing in the present art can provide the necessary compensation, except returning to the live fire range to zero the iron sights to accommodate the new shooter and returning to the Optical Alignment Fixture to adjust the laser beam boresight alignment to accommodate the new target distance. Such measures must be repeated to accommodate each change in targeting distance and shooter. Unless a weapon is properly boresighted and zeroed for the shooter and the desired target range, sight-picture compensation is necessary for a proper training experience.

[0014] There is accordingly a clearly-felt need in the art for a shooter sight-picture compensation system that can be integrated with the existing MILES 2000 in the training field without additional expensive and complex equipment. In particular, a compensation system is needed that relies on existing MILES 2000 field hardware and permits self-alignment of a zeroed SAT for another individual shooter in the training field whenever desired. To ensure effective training, a sight-picture alignment system is requires that customizes shooter sight-picture compensation for both the individual weapon and the individual shooter. These unresolved problems and deficiencies are clearly felt in the art and are solved by this invention in the manner described below.

SUMMARY OF THE INVENTION

[0015] This invention solves the above problem by adding elements of this invention to the existing Zeroed Small Arms Transmitter (ZSAT) assembly, or the Multiple Integrated Laser Engagement System (MILES) SAT that has been zeroed, to permit for the first time the automatic compensation of the shooter sight-picture without external test equipment. This invention arose in part from the unexpectedly advantageous observation that the dynamic muzzle displacement of a weapon during the first milliseconds is repeatable from shooter to shooter when a blank cartridge is fired through a blank fire adapter (BFA) affixed to the weapon muzzle in a predetermined angular disposition. The dynamic muzzle displacement during the first milliseconds after firing a blank cartridge through the BFA may be measured using, for example, high-speed video photography, and may be characterized as a two-dimensional laser-beam “dynamic muzzle displacement signature” in azimuth (AZ), elevation (EL) and time (T). This displacement signature is determined only by the BFA disposition and the shooter-independent characteristics of the weapon and the blank cartridge.

[0016] The term “calibration pixel” is used herein to denominate an optical signal representing a discrete angular position in a continuous dynamic muzzle displacement signature. A “pixel” may be embodied as, for example, a pulse-coded sequential beam number or a time-coded optical signal corresponding to a two-dimensional angle in AZ and EL. The dynamic muzzle displacement signature may be expressed, for example, as a time series (with fixed or variable time interval) of two-dimensional (AZ, EL) calibration pixels referenced to the initial SAT laser beam axis position (0,0), wherein each calibration pixel represents the angular position (AZ, EL) of the SAT laser beam at some time T after trigger pull.

[0017] This invention is a system and method for calibrating the shooter sight-picture offset and is also a method for employing the same system to compensate for the shooter offset during training exercises. According to this invention, any misalignment of the SAT laser beam axis with the shooter LOS is quickly calibrated by transmitting a coded sequence of optical pixel signals during a known portion of the dynamic muzzle displacement interval to represent the (AZ, EL, T) parameters for each of several calibration pixels. From the number and identity of the calibration pixel signals found to illuminate the target, a shooter-dependent LOS offset is deduced and stored. During later training exercises where the same weapon is used by the same shooter, this stored LOS offset is used in compensating for the target effects of any misalignment of the SAT laser beam axis with the shooter LOS.

[0018] The same calibration pixel signals are transmitted during later simulated fire. From the number and identity of the calibration pixel signals found to illuminate the target, as adjusted according to the stored LOS offset, the targeting effects of the misalignment of the SAT laser beam axis with the shooter LOS are cancelled. The available misalignment compensation is limited to the two-dimensional (AZ, EL) region illuminated by the SAT laser beam because at least some of the calibration pixel signals must illuminate the target bulls-eye during use.

[0019] It is a purpose of this invention to provide a system for automatically calibrating a misalignment of the laser beam axis with the shooter-dependent LOS by simply firing a blank cartridge while aiming at a target in the field.

[0020] It is another purpose of this invention to provide a system for automatically compensating for the shooter sight picture by calibrating a misalignment of the laser beam axis with the shooter LOS in two dimensions on a zeroed weapon.

[0021] In one aspect, the invention is a method for calibrating a misalignment of the laser beam axis with the shooter LOS in a weapon training system for simulating the use of a weapon against a target by a shooter having a LOS to the target, the system including a retroreflector adapted to be secured to the target for reflecting an incident optical signal back along the line of incidence, and a SAT assembly having a laser beam axis and adapted to be secured to the weapon, including the steps of (a) aligning the shooter LOS with the retroreflector, (b) triggering the weapon to fire a blank cartridge; (c) transmitting a sequence of optical pixel signals along the laser beam axis responsive to the weapon triggering step, (d) counting the number of optical pixel signals reflected from the retroreflector, and (e) storing a shooter LOS offset corresponding to the number of reflected optical pixel signals counted.

[0022] In another aspect, the invention is a weapon training system for simulating the use of a weapon against a target by a shooter having a LOS to the target, including a first optical detector adapted to be secured to the target for receiving an incident optical signal, a first counter coupled to the first optical detector for counting a number of optical pixel signals received at the first optical detector, and a SAT assembly having a laser beam axis and adapted to be secured to the weapon and having an optical transmitter and a sight-picture compensator for offsetting the misalignment of the laser beam axis with the shooter LOS to the target, including a controller coupled to the optical transmitter for producing an optical pixel signal sequence responsive to the triggering of the weapon and a data store coupled to the controller for storing a shooter LOS offset corresponding to the number of optical pixel signals counted.

[0023] In yet another aspect, the invention is a weapon training system for simulating the use of a weapon against a target by a shooter having a LOS to the target, including a retroreflector adapted to be secured to the target for reflecting an incident optical signal back along the line of incidence and a SAT assembly having a laser beam axis and adapted to be secured to the weapon, including an optical transmitter, an optical detector, and a sight-picture compensator for calibrating the misalignment of the laser beam axis with the shooter LOS, including a controller coupled to the optical transmitter for producing an optical pixel sequence responsive to the triggering of the weapon, a counter coupled to the optical detector for counting the number of reflected optical pixel signals received at the optical detector from the retroreflector, and a data store coupled to the counter for storing a shooter LOS offset corresponding to the number of reflected optical pixel signals counted.

[0024] In another aspect, the invention is a SAT assembly having a laser beam axis and adapted to be secured to a weapon for use in a weapon training system for simulating the use of the weapon against a target by a shooter having a LOS to the target and including a retroreflector secured to the target for reflecting an incident optical signal back along the line of incidence, the SAT assembly including an optical transmitter, an optical detector, and a sight-picture compensator for calibrating the misalignment of the laser beam axis with the shooter LOS, including a controller coupled to the optical transmitter for producing an optical pixel signal sequence responsive to the triggering of the weapon, a counter coupled to the optical detector for counting the number of reflected optical pixel signals received at the optical detector from the retroreflector, and a data store for storing a shooter LOS offset corresponding to the number of reflected optical pixel signals counted.

[0025] In yet another aspect, the invention is a method for precisely locating a simulated hit point on the target having a retroreflector including the steps of aligning the shooter LOS with the retroreflector, triggering the weapon to fire a blank cartridge, transmitting a sequence of optical pixel signals along the laser beam axis responsive to the weapon triggering step, counting a number of optical pixel signals reflected from the retroreflector, and determining the simulated hit point corresponding to the number of reflected optical pixel signals counted.

[0026] The foregoing, together with other objects, features and advantages of this invention, can be better appreciated with reference to the following specification, claims and the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] For a more complete understanding of this invention, reference is now made to the following detailed description of the embodiments as illustrated in the accompanying drawing, in which like reference designations represent like features throughout the several views and wherein:

[0028] FIG. 1 is a sketch illustrating the Zeroed Small Arms Transmitter (ZSAT) system of this invention for calibrating the misalignment of the ZSAT laser beam axis with the shooter line-of-sight (LOS);

[0029] FIG. 2 is a sketch illustrating the ZSAT and weapon details of FIG. 1;

[0030] FIG. 3 is a sketch illustrating the shooter sight line, projectile trajectory line and ZSAT laser beam axis details of FIG. 1;

[0031] FIG. 4 is a block diagram illustrating an exemplary embodiment of the ZSAT assembly portion of the ZSAT calibration system of this invention;

[0032] FIG. 5 a block diagram illustrating an alternative embodiment of the target portion of the ZSAT calibration system of this invention;

[0033] FIG. 6 is a sketch illustrating another alternative embodiment of the target portion of the ZSAT calibration system of this invention;

[0034] FIG. 7 is a sketch illustrating yet another alternative embodiment of the target portion of the ZSAT calibration system of this invention;

[0035] FIG. 8 is a chart illustrating an exemplary two-dimensional dynamic muzzle displacement signature characterizing a weapon upon firing a blank cartridge through a Blank Fire Adaptor (BFA) affixed to the weapon muzzle, according to the teachings of this invention;

[0036] FIG. 9 is a chart illustrating the first quarter-cycle of the exemplary dynamic muzzle displacement signature of FIG. 8 showing an exemplary embodiment of the predetermined two-dimensional pixel sequence of this invention;

[0037] FIG. 10 is a chart illustrating the horizontal pixel components of the dynamic muzzle displacement signature of FIG. 8 versus time after trigger pull;

[0038] FIG. 11 is a block diagram of a flow chart illustrating the automatic sight picture alignment method of this invention; and

[0039] FIGS. 12A-12D are charts illustrating an exemplary embodiment of the method of this invention for deducing the horizontal component of a shooter LOS offset from the number and identity of the target-illuminating optical pixel signals.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0040] FIGS. 1-3 illustrate various elements of the Zeroed Small Arms Transmitter (ZSAT) system 20 of this invention for calibrating any misalignment of the laser beam axis 22 of the ZSAT assembly 24 with the line-of-sight (LOS) 36 of a shooter 26. Such misalignment usually exists in a zeroed weapon that has not been re-zeroed by a new shooter. ZSAT assembly 24 is affixed to the weapon 28, which is aimed by shooter 26 along the LOS 36 to the target bulls-eye 30. FIG. 2 shows ZSAT assembly 24 affixed to weapon 28 in more detail. Weapon 28 includes a rear sight 32 and a forward sight 34, both of which are aligned along LOS 36 by shooter 26. As seen more clearly in FIG. 3, shooter LOS 36 is distinguished from laser beam axis 22 and from the boresight axis of the muzzle 38 to which a blank fire adapter (BFA) 40 is affixed substantially as shown. LOS 36 and axis 22 are also distinguished from trajectory 42 (FIG. 1) of a live projectile fired from muzzle 38, which describes a parabola aligned at one end with the boresight axis of muzzle 38. As illustrated in FIG. 1, when LOS 36 is aligned with the collinear bulls-eyes 30A-30B, sights 32-34 are said to be properly “zeroed” (at 25 and 300 meters) for shooter 26 when live projectile trajectory 42 rises to the bulls-eye 30A at 25 meters, continues to a peak, and then falls to the collinear bulls-eye 30B at 300 meters as illustrated. In accordance with this invention, the targeting effects of any misalignment of laser beam axis 22 with shooter LOS 36 in a weapon may be automatically compensated without mechanical adjustment to any elements of the system.

[0041] FIG. 4 is a block diagram illustrating the ZSAT calibration system 44 of this invention in an embodiment adapted for use with ZSAT assembly 24 (FIGS. 1-3). The optical transmitter 46 may be embodied as, for example, an infrared (IR) laser with a wavelength in the region from generally 800 nanometers to generally 10,600 nanometers and preferably close to 1540 nanometers. The 1540 nanometer signal wavelength is preferred because it is eye-safe even at twenty times the necessary power levels and pulse rates and has lower absorption and scattering loss in smoke and haze than at 904 nm. The encoder 48 is coupled to optical transmitter 46 for encoding the sequence of optical (AZ, EL) pixel signals transmitted along axis 22 under the control of a controller 50. A trigger-pull sensor 52 passes a signal to controller 50 that the shooter has pulled the weapon trigger (perhaps firing a blank cartridge to initiate the calibration procedure). The pixel signals may be encoded in one dimension only (AZ, for example), in two dimensions (AZ and EL, for example), or sequentially along the dynamic muzzle displacement signature, for example.

[0042] In one embodiment of this invention, all elements of calibration system 44 are collocated in the ZSAT assembly 24 affixed to weapon 28 (FIGS. 1-3), including the LOS offset logic 54, which includes an optical sensor 56 for receiving optical pulses 57 reflected from a retroreflector disposed at target bulls-eye 30 (FIGS. 1 and 3). Any suitable retroreflector known in the art is employed at the target to implement the calibration procedure of this invention. For example, one of the line of Tech Spec™ Corner Cube Retroreflectors (Trihedral Prisms) available from Edmond Industrial Optics, Barrington, N.J. is suitable for this purpose. Optical sensor 56 sends a signal representing a received optical pulse to the counter logic 58 and the decoder logic 60, both of which are coupled to controller 50 and operate to recover a shooter LOS offset in accordance with this invention. Decoder logic 60 decodes the received pulses to identify the pixel signals, which are accumulated by counter logic 58 and passed to controller 50, which stores the pixel count number in a data store 62 for later use in performing shooter sight picture compensation. Decoder logic 60 also may operate to recover any optical pulse coding that may have been created by encoder 48 at transmission and this coding is passed to controller 50 for use in identifying individual pixel signals to support alternative embodiments of the sight picture compensation method of this invention. After calibration and storage of the pixel count number in data store 62, controller 50 may perform offset compensation by first receiving and counting the pixel signals reflected from the target retroreflector and then adjusting this count according to the stored LOS offset to obtain an adjusted count from which the precise target hit location may be deduced in the manner described below in connection with FIGS. 12A-12D.

[0043] In an alternative embodiment of this invention that does not require a target retroreflector, the elements of calibration system 44 represented by offset logic 54 are collocated at the target as shown in FIG. 5 instead of being located at the shooter as shown in FIG. 4. The offset logic 64 is coupled to an optical sensor 66 at target bulls-eye 30 (FIGS. 1-3) for recovering the optical pixel signals arriving along laser beam axis 22. Optical sensor 66 may be alone or may cooperate with one or more other optical sensors in an optical sensor array 68 spanning the target around bullseye 30, for example. A counter logic 70 and a decoder logic 72 operate similarly to logics 58 and 60 (FIG. 4) to recover pixel signal count numbers and selected pulse codes, which are reduced to a shooter LOS offset by the controller 74. Controller 74 stores the shooter LOS offset in the data store 76 and causes the offset signal transmitter 78, embodied as a radio frequency (RF) or millimeter wave (MMW) transmitter, for example, to transmit an offset signal 80 to the optional offset signal receiver 82 shown in FIG. 4, from where the shooter LOS offset is passed to controller 50. System 44 may include either offset logic 54 or offset signal receiver 82, or both, for example, thereby permitting the shooter to recalibrate his sight-picture compensation in the field during an exercise, if necessary.

[0044] In another alternative embodiment of this invention, another soldier may be equipped to wear the target portion of the ZSAT calibration system of this invention, including target bulls-eye 30 (FIGS. 1 and 3). For example, FIG. 6 shows another soldier wearing a vest 84 to which is fixed a target bulls-eye 86 including, for example, a retroreflector or an optical sensor. If bulls-eye 86 includes a retroreflector, vest 84 may passively cooperate with the sight-picture calibration procedure performed by a distant ZSAT assembly. Alternatively, if bulls-eye 86 includes an optical sensor, vest 84 also includes the signal processing electronics 88 for performing the functions discussed above in connection with FIG. 5, for example. Moreover, electronics 88 may include additional devices for recording and reporting hits and misses, which are beyond the scope of this discussion. This is a useful embodiment because the MILES 2000 training system known in the art, for example, includes vests and H-harnesses equipped to detect and report simulated small arms hits and misses during training exercises. These vests may be easily adapted by adding firmware to operate as discussed above in connection with FIG. 5, for example.

[0045] FIG. 7 illustrates yet another alternative embodiment of this invention, where vest 84 is equipped with a sensor array 90, including optical sensor 86, for use in collecting transmitted optical pixels in two dimensions in accordance with a precision hit/miss detection method of this invention, which may be appreciated with reference to the following discussion in connection with FIGS. 12A-12D.

[0046] FIG. 8 is a chart illustrating an exemplary two-dimensional dynamic muzzle displacement signature 92 characterizing a weapon upon firing a blank cartridge through a BFA affixed to the weapon muzzle as shown in FIGS. 1-3, for example. The inventors have advantageously observed that a small arms weapon oscillates during the firing of a shot. The oscillation frequency and amplitude are determined by the transfer of the breech mass forwards and backwards under the impulsive force of the cartridge detonation and subsequent gas expulsion from the muzzle, which may be equipped with a BFA. The impulse force is translated into lateral motion by the resolved lateral force acting on a lever arm formed between the breech mechanism and the shooter's forward grip. The inventors have observed that the oscillation frequency and amplitude are a reasonably invariant function of the weapon topology and mass.

[0047] In FIG. 8, dynamic muzzle displacement signature 92 represents several of the features noted by the inventors during repeated experimental measurements of a blank cartridge fired from a weapon equipped with a BFA fixed in a consistent disposition to the weapon muzzle (FIGS. 1-3). Assuming a horizontal BFA gas port disposition directing gas to the left, the first quarter cycle portion 94 of the sinusoidal oscillation is mainly from left to right, although a smaller sinusoidal vertical oscillation may be noted. Displacement signature 92 is shown beginning at the initial aimpoint 23 of ZSAT laser beam axis 22 (FIGS. 1-3) and proceeding, for this example, to the right at about 0.2 milliradians per millisecond for about 10 milliseconds. The vertical and horizontal cycles continue, describing a path about the initial aimpoint 23 substantially as shown. The first quarter-cycle portion 94 from 0-10 milliseconds is useful for the LOS calibration system of this invention, as is now described.

[0048] FIG. 9 illustrates a two-dimensional dynamic muzzle displacement signature 96 representing the AZ and EL angles of the first quarter-cycle 94 (FIG. 8) for a blank cartridge fired from a weapon equipped with a BFA fixed in a predetermined disposition to the weapon muzzle. The period of displacement signature 96 is about 10 milliseconds and the (AZ, EL, T) coordinates of the exemplary pixels shown in FIG. 9 can be saved in a data store in a form that represents displacement signature 96 corresponding to the predetermined BFA disposition on the weapon. Displacement signature 96 can be measured using, for example, high-speed video equipment and a laboratory fixture, for any combination of small arms weapon, blank cartridge, and BFA disposition.

[0049] When triggering the weapon to fire a blank cartridge, the dynamic muzzle displacement may be exploited to paint the target with a sequence of optical pixels transmitted from ZSAT 44 (FIG. 4) in synchronization with the dynamic muzzle displacement rate. For example, ten pixels exemplified by the pixel 97, are evenly distributed over signature 96, representing one pixel signal transmission every one millisecond after trigger pull. In this example, each pixel position would differ from the previous pixel position by about 0.4 milliradians in AZ and perhaps 0.2 milliradians or so in EL.

[0050] FIG. 10 is a chart illustrating another exemplary embodiment of the optical pixel sequence of this invention transmitted upon triggering a weapon having dynamic muzzle displacement signature 96 (FIG. 9). For expository purposes, FIG. 10 shows only the horizontal AZ component 98 of displacement signature 96 versus time T in milliseconds. In this example, the pixel signals are encoded as a sequence and spaced at 0.5 millisecond intervals such that the AZ of each pixel differs from the AZ of its neighbor by about 0.2 milliradians. Beginning at trigger pull (T=0), the first few hundred microseconds are reserved for the projectile transit interval 100 and the next couple of milliseconds are reserved for the muzzle gas cloud dissipation interval 102, during which periods the optical signals are not usefully propagated. Muzzle gas cloud dissipation interval 102 ends at about 2.5 milliseconds. The sequence of optical pixel signals within the calibration interval 104 includes, for example, sixteen pixels spaced at about 0.2 milliradians, beginning with the pixel 106 (encoded as P00) after the muzzle gas cloud has dissipated (to avoid beam distortion effects) and ending with the pixel 108 (encoded as P15). Preferably, each optical pixel signal is encoded (P00, P15 for example) to permit pixel identification and to permit reordering or recoding of the pixel sequence to compensate for the shooter LOS offset. However, the method of this invention is not necessarily limited to an embodiment using sequential optical pixel encoding. FIG. 9 also demonstrates that, while the pixel sequence in interval 104 is preferably evenly-spaced in AZ, it may not necessarily be linearly spaced in time.

[0051] FIG. 11 is a block diagram of a flow chart illustrating the automatic sight picture alignment method of this invention. At the first step 116, the new shooter aligned the LOS with the target, which may include a retroreflector or a sensor. The shooter then triggers the weapon to fire a blank cartridge through the BFA at step 118. Within milliseconds, the ZSAT sends a predetermined series of laser pulses encoded as pixels to the target in step 120. In step 122, the pixels illuminating the target are detected and counted, either at the target by a sensor, for example, or at the shooter by means of target retroreflections, for example. In the step 124, a pixel count is stored, at the shooter, for example, and used to modify the pixel encoding to compensate for shooter sight-picture misalignment during later blank cartridge fire.

[0052] FIGS. 12A-12C are charts illustrating an exemplary embodiment of the method of this invention for deducing the horizontal component of a shooter LOS offset from the number and identity of the target-illuminating optical pixels. For expository purposes, the EL component and the effects of projectile transit interval 100 and muzzle gas cloud dissipation interval 102 (FIG. 10) are ignored. FIG. 12A shows laser beam 22 centered at aimpoint 23 (AZ=0) on retroreflector 109, which coincides with the shooter LOS in these examples. The rate of muzzle displacement is assumed to be 0.4 milliradians per millisecond to the right so the displacement signature will move the laser beam from (AZ=0) to the right by +1.6 milliradians in 4 milliseconds. Assuming that two pixel signals are transmitted per millisecond, the 3.2 milliradian laser beam moves off of retroreflector 109 after about 4 milliseconds. With these assumptions, the first eight pixel signals in calibration interval 104 (FIG. 10) are reflected and the subsequent pixel signals are not. Eight pixels are reflected and detected and eight are not (assuming a 16-pixel sequence). With this exemplary arrangement, receiving the first half of the pixels signifies a zero LOS offset from laser beam axis 22 (the laser beam center). That is, a zero LOS offset means that the shooter LOS and the ZSAT laser beam axis are coincident at the target distance.

[0053] FIG. 12B shows aimpoint 23 (AZ=0) of laser beam axis 22 offset by 1.6 milliradians to the right of the shooter LOS at retroreflector 109, representing a shooter LOS error of +1.6 milliradians. Using the parameters discussed above in connection with FIG. 12A, even the first pixel signal does not illuminate retroreflector 109 because the positive (right) offset error is not less than half of the 3.2 milliradian laser beam width. Accordingly, any errors of +1.6 milliradians or more cannot be calibrated without broadening the ZSAT laser beam width. Any less of a right offset is detected as one or more pixel signal reflections. In these examples, the LOS offset error can be calibrated to within 0.2 milliradians, which is only 6.25% of the 3.2 milliradian ZSAT laser beam width. This vernier feature of this invention for the first time allows the offset calibration precision to substantially exceed the ZSAT laser beam width.

[0054] FIG. 12C shows the laser beam aimpoint 23 (AZ=0) offset by 1.6 milliradians to the left of retroreflector 109, representing a shooter LOS error of −1.6 milliradians. Using the parameters discussed above in connection with FIG. 16A, all sixteen pixel signals including the last one will illuminate retroreflector 109 because the negative offset error is not less than half of the 3.2 milliradian laser beam width. Accordingly, any negative errors of −1.6 milliradians or more cannot be calibrated without broadening the ZSAT laser beam width. Any less of a left offset is detected as one or more fewer pixel signal reflections.

[0055] It may be readily appreciated from this description of FIGS. 12A-12C that any LOS offset in the interval between [−1.6, +1.6] milliradians may be calibrated and stored as a pixel signal count for later use in compensating for the shooter LOS offset. FIG. 12D shows that this method of this invention may also be used to precisely refine the location of “hit” and “kill” points on a target including an array of sensors such as is shown in FIG. 7. This “precision” hit/kill point resolution is refined far beyond the precision possible with a simple detection of a 3.2 milliradian laser beam. Consider the retroreflector array in FIG. 12D made up of the sensors 110A-B, which are spaced apart by 4 milliradians (about 4 cm at 25 m, or about 50 cm at 300 m). Assuming that the shooter LOS aimpoint 23 (represented by pixel P00) is positioned at about −2.8 milliradians to the left of sensor 10B and about +1.2 milliradians to the right of sensor 11A. With the assumptions described above in connection with FIG. 12A, sensor 110A detects pixel signals (P00-P01) and misses the others (P02-P15). Sensor 110B misses pixel signals (P00-P06) and detects pixel signals (P07-P15). Accordingly, the target system can precisely locate aimpoint 23 at −0.4 milliradians on the scale shown in FIG. 12D. This precision is within 0.2 milliradians (5 mm at 25 m or 6 cm at 300 m) even though a 3.2 milliradian laser beam is used for targeting. It may be readily appreciated that the described method may be extended to one- and two-dimensional arrays of multiple sensors. This same precision is also possible using the method of this invention with a single target sensor or retroreflector (such as shown in FIGS. 12A-C) located within 1.6 milliradians of the target kill point.

[0056] Practitioners in the art can readily appreciate that other beam widths, pixel sequences, and target characteristics may be selected to adapt the calibrating method of this invention to different weapon and BFA characteristics. For example, by coding the optical pixel sequence in interval 104 (FIG. 10) to identify the vertical and horizontal LOS offsets recorded for truncated dynamic muzzle displacement signature 96, a two-dimensional LOS offset may be deduced from the number and coding of the pixels detected at bulls-eye 30. As another example, during calibration, a useful pixel computation method may be advantageously employed in lieu of the simple pixel counting technique described above to determine a calibration offset value that may be then used with another computation method to correct shooter LOS offset during exercises.

[0057] When the misalignment of laser beam axis aimpoint 23 with shooter LOS 36 (FIG. 3) is calibrated and stored, the shooter LOS offset compensation remains in data store 62 (FIG. 4) until the ZSAT is recalibrated by another shooter. In use, shooter sight picture compensation may be achieved from the stored LOS offset in any of several useful ways. For example, an integer number N related to the stored pixel offset calibration results may be subtracted from each pixel code detected during interval 104 by vest 84, which is worn by the target during the training shot. Thus, optical pixel (P00-N) is recognized as the “kill” signal by vest 84 instead of first pixel signal P00, which is known to be misaligned. Alternatively, the vest software may be adapted to decode the offset pixel code (N) and/or Global Positioning System (GPS) data received from the ZSAT. Using this offset pixel code and the GPS coordinates, the vest may conduct a hit/miss assessment based on the pixels signals detected at the bulls-eye.

[0058] Following sight picture calibration according to any method of this invention, a standard MILES 2000 vest and a standard MILES SAT modified to delay transmission of the standard MILES 2000 SAT pulse codes by a time interval representing the stored LOS offset. That is, by adding the sight-picture calibration software of this invention to the MILES SAT and adding a retroreflector to the MILES 2000 vest, merely delaying transmission of the standard MILES 2000 SAT beam codes according to the stored LOS offset compensates for the shooter sight picture error without resorting to a live-fire target facility.

[0059] Clearly, other embodiments and modifications of this invention may occur readily to those of ordinary skill in the art in view of these teachings. Therefore, this invention is to be limited only by the following claims, which include all such embodiments and modifications when viewed in conjunction with the above specification and accompanying drawing.