METHOD AND APPARATUS FOR IMPROVING THE AIM OF A WEAPON STATION, FIRING A POINT-DETONATING OR AN AIR-BURST PROJECTILE

Abstract

The method and apparatus for a remote weapon station or incorporated into manually-aimed weapons. The methodology requires use of a muzzle velocity sensor that refines the aiming of the second and subsequent fires or volleys fired from weapon systems. When firing the first volley a weapon uses an estimated velocity and, at firing, the muzzle velocity of a projectile is measured. When firing the second volley a weapon's fire control calculates an aiming point using the measured velocity of the first volley.

Claims

1. A system located in the vicinity of a weapon having a barrel for firing a succession of projectiles that follow extenuated curved ballistic trajectories-toward a distant target, said system being operative when each projectile is fired from the weapon to record its changing vertical and lateral positions over its ballistic path during its ballistic flight after barrel exit, said system comprising, in combination; a radiation source at the location of the weapon for transmitting radiation toward the rear surface of the projectile during its ballistic flight, where said radiation source is a steerable laser beam with a control for causing the radiation emitted from the laser to intersect with the ballistic path of the projectile; a radiation detector at the location of the weapon for detecting return radiation received from the rear surface of the projectile in response to said radiation emitted by said radiation source and capturing said changing vertical and lateral positions of the projectile during its ballistic flight, said detector producing measurable output signals representing said changing vertical and lateral positions of the projectile; and an output device, coupled to the radiation detector and receiving said output signals, for recording said changing vertical and lateral positions of the projectile as it exits the barrel transitioning to the apogee, and for calculating an adjustment in the aim of the weapon toward the target, prior to firing a subsequent projectile, the output device further comprising a sensor measuring drop and drift of the projectile, wherein the sensor tracks said extenuated ballistic curve.

2. The system defined in claim 1, wherein said output device comprises: a) a signal processor, coupled to the radiation detector, for processing said electronic signals to determine the spatial (X and Y) coordinates of the projectile during flight; and b) a computer, coupled to the signal processor and to the output device, for calculating a lateral correction and a vertical correction in the aim of the weapon; wherein said output device facilitates the lateral and vertical correction in the aim of the weapon.

3. The system defined in claim 1, wherein the output device produces a lateral and vertical correction to the aim of the weapon.

4. The system defined in claim 1, wherein the output device allows for adjustment of the aim of the weapon by imparting, post firing, lateral and vertical corrections to the aim.

5. The system defined in claim 2, wherein one of the signal processor and the computer calculates the lateral drift and the vertical drop of the projectile during its ballistic flight.

6. The system defined in claim 1, wherein the radiation emitted from the laser source is diffused and directed to optimize illumination of the projectile's flight path.

7. The system defined in claim 1, wherein the radiation detector is a digital video camera for capturing an image of the ballistic path of the projectile.

8. The system defined in claim 1, wherein the radiation detector includes a filter, allowing the radiation received from the projectile to be selectively received and other radiation excluded.

9. The system defined in claim 1, wherein the frequency of said radiation is in one of the UV, visual and IR spectral bands.

10. The system defined in claim 1, wherein said output device includes a display showing said vertical and lateral positions of the projectile.

11. The system defined in claim 9, wherein said output device includes a aiming device allowing an operator to adjust the aim of the weapon.

12. The system defined in claim 1, wherein the radiation source emits timed radiation signals at specific time intervals.

13. The system defined in claim 1, wherein said radiation source is a source of pulsed radiation directed toward the ballistic path of the projectile and emitted at predetermined times (T1, T2, T3 . . . Tn) following firing of the projectile (at time T0) and wherein said radiation detector receives radiation signals retro-reflected from the projectile at times (T1z, T2z, T3z . . . Tnz) and produces electronic signals representing the vertical and lateral positions of the projectile at said times (T1z, T2z, T3z . . . Tnz), where z is a round trip transmission time of the radiation and T1z, T2z, T3z . . . Tn are the respective times T1, T2, T3, . . . Tn each delayed by amount z.

14. The system defined in claim 1, wherein said projectile has an elongate circular body with side and rear surfaces and a photo-luminescent material, disposed on the rear surface, that re-emits radiation at when excited by receipt of radiation from the radiation source.

15. The system defined in claim 14, wherein said photo-luminescent material is additionally disposed on a side surface of the projectile body.

16. The system defined in claim 14, wherein said photo-luminescent material is a fluorescent dye.

17. The system defined in claim 1, wherein said projectile has an elongate circular body with side and rear surfaces a retro-reflective element, disposed on the rear surface, that reflects radiation received from a radiation source in the direction of the radiation source.

18. The system defined in claim 17, wherein said retro-reflective element is additionally disposed on a side surface of the projectile body.

19. The ammunition projectile defined in claim 17, wherein said retro-reflective element is affixed to the projectile body.

20. The ammunition projectile defined in claim 17, wherein said retro-reflective element is coated on the projectile body.

21. The system defined in claim 17, wherein said retro-reflective element is positioned and oriented on the projectile body to allow for the rearward travel of reflected light, notwithstanding a yawing motion of the projectile during flight.

22. The system defined in claim 17, wherein said retro-reflective element is selected from the group consisting of corner cube reflectors, cat eyes and phase conjugated mirrors.

23. A system for correcting the aim of a weapon which is operative to launch a projectile from a barrel on a ballistic path toward a target, the projectile having an elongate housing with a rear end and fluorescent dye material disposed on the rear end that produces radiation at a first frequency when excited by receipt of radiation at a second frequency, said aim correcting system comprising, in combination; (1) a radiation source of pulsed light at said first frequency directed toward the ballistic path of the projectile and emitted at predetermined times (T1, T2, T3 . . . ) following firing of the projectile (at time T0); (2) a radiation detector at the location of the weapon for receiving light radiation signals re-emitted by the fluorescent dye on the projectile at times (T1z, T2z, T3z . . . Tnz) and producing electronic signals representing the vertical and lateral positions of the projectile at said times (T1z, T2z, T3z, . . . Tnz), where z is a re-emission delay and T1z, T2z, T3z . . . are the respective times T1, T2, T3, . . . Tn each delayed by amount z; (3) a signal processor, coupled to the radiation detector, for processing said electronic signals to determine the spatial (X and Y) coordinates of the projectile at said times (T1z, T2z, T3z, . . . Tn) during flight; (4) a computer, coupled to the processor, for calculating a lateral correction and a vertical correction in the aim of the weapon; and (5) an output device, coupled to the computer, for facilitating an adjustment in the aim of the weapon toward the target, prior to firing the next projectile; wherein said aim of the weapon may be adjusted after launch of the projectile to compensate for errors prior to launch of another projectile.

24. The system defined in claim 23, wherein one of the signal processor and the computer calculates the lateral drift and the vertical drop of the projectile at said predetermined times.

25. The system defined in claim 23, wherein said radiation source is laser source, configured to be affixed to the weapon so that a cone of illumination of the laser source intersects with the ballistic path of the projectile and excites the fluorescent dye material.

26. The system defined in claim 25, wherein said laser source transmits light through a narrow band-pass filter so that the cone of illumination in a narrow frequency range intersects the ballistic path of the projectile and excites the fluorescent dye material.

27. The system defined in claim 23, wherein the radiation detector is a digital camera for producing an image of the ballistic path of the projectile.

28. The system defined in claim 23, wherein the radiation detector includes a narrow band-pass filter, allowing re-emitted light from the fluorescent dye material to be selectively received and other light excluded.

29. The system defined in claim 26, wherein said fluorescent dye on the rear surface of the projectile responds preferentially to the laser light illumination in the narrow frequency range.

30. The system defined in claim 23, wherein said fluorescent dye on the rear of the projectile has a protective transparent coating.

31. The system defined in claim 23, wherein said first frequency is in one of the UV, visual and IR spectral bands.

32. The system defined in claim 23, wherein said output device is a display.

33. The system defined in claim 32, wherein said output device includes a aiming device allowing an operator to adjust the aim of the weapon.

34. The system defined in claim 23, wherein the output device allows for adjustment of the aim of the weapon by imparting, post firing, lateral and vertical corrections.

35. The system defined in claim 23, wherein the signal processor determines the time duration of the radiation signals received at said second frequency in response to radiation pulses emitted at said first frequency, and wherein said computer distinguishes the signals received from each projectile from among signals received from other, successively fired projectiles in dependence upon said time duration.

36. The system defined in claim 35, further comprising an electronic control circuit with a clock that modulates the radiation source to emit radiation with specific time durations at specific times, thereby producing a strobe effect, illuminating the projectile's ballistic path along the projectile's ballistic flight to the target.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] FIG. 1A depicts a system diagram and function sequence for a prior Art Kongsberg Remote Weapon Station (RWS).

[0038] FIG. 1B depicts 40 mm terrestrial target ballistics at 1000 meters for the RWS shown in FIG. 1A.

[0039] FIG. 1C depicts a detail of the 40 mm terrestrial target ballistics at 1000 meters shown in FIG. 1B.

[0040] FIG. 1D depicts 40 mm drone (UAS) target ballistics at 1000 meters for the RWS shown in FIG. 1A.

[0041] FIG. 1E depicts a detail of the 40 mm UAS target ballistics at 1000 meters shown in FIG. 1D.

[0042] FIG. 1F depicts prior Art 40 mm terminal ballistics using the methodology described in the U.S. Pat. No. 9,600,900.

[0043] FIG. 1G is a graph of theoretical versus measured muzzle velocity and P(hit).

[0044] FIG. 1H shows modeling results for 40 mm53 uncorrected volleys.

[0045] FIG. 2A shows a US M151 Remote Weapon Station (RWS) with a muzzle velocity (MV) measurement device on a MK19 firing an ammunition projectile.

[0046] FIG. 2B shows a US M151 RWS with an MV measurement device on a MK19 firing an optically programmed projectile.

[0047] FIG. 2C shows a US M151 RWS with an MV measurement device on a MK19 firing an RF or extended range magnetically programmed projectile.

[0048] FIG. 2D shows a US M151 RWS with an MV measurement device.

[0049] FIG. 2E depicts 40 mm UAS target ballistics at 1000 meters for the US M151 RWS with an MV measurement device shown in FIG. 2D.

[0050] FIG. 2F depicts the average miss distance resulting from a 40 mm (lot) muzzle velocity variation from a ballistic solution's theoretical solution.

[0051] FIG. 3A is a system block diagram for a US M151 RWS, improved with the addition of a muzzle velocity measurement and an air-burst programmer.

[0052] FIG. 3B is a system block diagram for a US M151 RWS, firing a second volley with an improved system function to measure muzzle velocity, adjusting elevation and firing a programmable air-burst projectile. The table in the top left corner of the figure depicts a method of computation used in the fire control ballistic computer and a resulting elevation solution.

[0053] FIG. 3C is a system function sequence diagram for an exemplary initial commutation, based on an algorithm or table, identifying an elevation solution for a second volley with a re-adjusted elevation, where the weapon system previously measured the first volley muzzle velocity.

[0054] FIG. 3D is a system function sequence diagram for a second volley elevation solver using a histogram of prior shots data, producing a revised solution for a second and subsequent volleys. The diagram depicts sequencing of volleys and fire control sub-routines where a first volley calculates a solution based on a default muzzle velocity and second and subsequent volleys use actual measured muzzle velocity.

[0055] FIG. 4A depicts a manually-adjusted weapon, with a muzzle velocity sensor, a fire control and range finder incorporated into external binoculars.

[0056] FIG. 4B depicts two views of an MK19 weapon from the gunner's perspective, showing a range output and an adjustment indicator.

[0057] FIG. 4C is a system function sequence diagram showing an initial and subsequent elevation solutions.

[0058] FIG. 4D depicts a manually-adjusted weapon, with a muzzle velocity sensor and a fire control device with a range finder incorporated into external binoculars. The weapon system is fitted with an optical programmer to set the detonation time of a programmable projectile.

[0059] FIG. 4E depicts a manually-adjusted weapon, with a muzzle velocity sensor and a fire control device with range finder incorporated into external binoculars. The system is fitted with an RF or Extended Range Magnetic Induction programmer to set the detonation time of a programmable projectile.

[0060] FIG. 4F depicts a manually-adjusted weapon, with a muzzle velocity sensor and a fire control device with range finder incorporated into external binoculars. The system is fitted with an Oerlikon AHEAD type of programmer to set the detonation time of a programmable projectile.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0061] The relevant prior art as well as the preferred embodiments of the present invention will now be described with reference to FIGS. 1A-4F of the drawings. Identical elements are designated with the same reference numerals.

[0062] Prior Art:

[0063] For context and for an understanding of the present state of the art, it is useful to examine the existing remote weapon station configurations to illuminate how lot-to-lot variation of mean muzzle velocity in 40 mm cartridges influences calculated aiming solutions. FIGS. 1A-1F depict benchmarks and performance characteristics delivered in existing systems.

[0064] FIG. 1A includes diagrams similar to those in the U.S. Pat. No. 8,286,872 for a remote weapon station optimized to fire air-burst ammunition. FIG. 1B depicts a 40 mm AGL ballistic flight path when aimed to impact near a ground target at 1000 meters.

[0065] Most fire control algorithms, presently in use, use encoded reference elevation tables and algorithms with an assumed standard muzzle velocity to calculate elevation. Unfortunately, the lot-to-lot variations of 40 mm53 ammunition often result in the remote weapon station's missing their targets at extended ranges. FIG. 1B shows both the ballistic flight 44mva of a cartridge fired with a 1 sigma muzzle velocity (lower muzzle velocity compared to the firing table algorithm) and the ballistic flight path 44mvb of a cartridge fired with a 1 sigma muzzle velocity (above the firing tables average muzzle velocity). FIG. 1C is an enlarged view of the terminal ballistics resulting from the varying muzzle velocities 44mv0, 44mva and 44mvb, depicting the detonation of a programmable 40 mm53 air-burst ammunition projectile when fired along the ballistic flight path.

[0066] FIG. 1D depicts the ballistic path 44 of a 40 mm AGL projectile firing at a target at an elevation of 90 meters and, for a set time, the detonation locations 46mva, 46mv0 and 46.sub.mvb along the flight paths 44mva, 44mv0 and 44mvb, respectively, for ammunition without adjusted programmed time to detonation and without and second volley elevation adjustment. FIG. 1E illustrates the burst point variation transposed over a target UAV 42. FIG. 1F depicts the utility of adjusting the programmed flight time (to detonation) T2 in accordance with the method disclosed in the U.S. Pat. No. 9,600,900, and an automated elevation adjustment according to the present invention.

[0067] FIG. 1G is a simple graph, produced from modeling, identifying the mean miss distance of 40 mm high velocity ammunition for known projectile mean lot variation. FIG. 1H is a table showing the calculated probability of the average and adjusted miss distance for a first volley, as the muzzle velocity of a lot varies from the mean.

[0068] The purpose of the present invention is to improve a gunner's aiming for second and subsequent volleys. I may be incorporated into both remote weapon stations and manually-controlled weapon and fire control combinations.

[0069] FIGS. 2A, 2B, 2C and 2D, with reference to corresponding FIGS. 3A, 3B, 3C and 3D, respectively, depict several embodiments 10 of the subject invention incorporated into a remote weapon station, with a muzzle velocity measurement device 52, that fires a projectile 60. The unfired projectiles are fitted in cartridges 66, that are stored in an ammunition can 68, in the rack of a Remote Weapon Station (FIG. 2A). These embodiments include a fire control computer 12, having a memory storage 12B and running a fire control algorithm 12D, mounted into a mechanical support 18 on a weapon. The muzzle velocity measurement device 52 feeds data to the memory storage 12B and the fire control algorithm 12D calculates the ballistic flight path. The system preferably incorporates a programmer 54 capable of programming ammunition projectiles 64 when they are fired from the weapon.

[0070] FIG. 2C depicts an RF programmer 54B on the muzzle of the weapon that programs an RF programmable projectile 64B. After a first volley V1, the system automatically re-aims, the mounted weapon producing an improved aiming elevation.

[0071] The embodiments of the invention shown in FIGS. 2A, 2B, 2C and 2D operate to fire a projectile 60, which may be conventional 62 or programmable 64. These embodiments include a muzzle velocity measurement device 52 that measures each projectile's muzzle velocity MV, stores this muzzle velocity in the memory 12B, and then employs the ballistic algorithm 12D to recalculate and reset the elevation 22B after firing. The second and subsequent volleys thus have an improved aim elevation, compared to the first volley.

[0072] FIG. 2D depicts an in-bore programmed projectile 64D, with an in-bore muzzle velocity measurement and programmer 54D as provided for in the Oerlikon (AHEAD) patents referred to above, which are licensed to STK (Singapore) and to General Dynamics Ordnance and Tactical Systems (US).

[0073] FIGS. 2E and 2F depict the expected improvement in firing with an unmanned system located at a range of 1000 meters and at an altitude of 90 meters. FIG. 2E depicts the projectile's improved ballistic path 44C, and the projectile's detonation at an adjusted time T2 in close proximity to the target 42. FIG. 2F depicts the forecasted improvement of a remote weapon station with the remote adjustment of the second volley, where the first volley V1 has a low probability of hit and the second volley V2 has an improved probability of hit P1. The initial aim point 12E for the initial firing test uses the assumed muzzle velocity for the lot of ammunition.

[0074] FIG. 3A depicts a remote weapon station system with a muzzle velocity measurement device 52A, 52B, 52C and programmer 54. With reference to FIG. 3B, the remote weapon station firing a first engagement volley aims the weapon using a theoretical or default muzzle velocity 12C and may adjust the users aiming point 12F. As represented in FIG. 3C, a second volley is aimed using a ballistic solution algorithm 12D that runs, based on the measured muzzle velocity. FIG. 3C depicts the sequence of fire control sub-routines of a first, second and subsequent volley.

[0075] FIG. 3A is an external view of improved remote weapon configuration according to the invention, with a muzzle velocity measurement device 52 mounted on a weapon's muzzle.

[0076] FIG. 3B shows a system diagram for US M151 RWS Remote Weapon Station that includes a conventional muzzle velocity measurement device 52A, or a radar device 52B that may include a position sensor 52C, such as that disclosed in U.S. Pat. No. 8,074,555. This RWS system operates with a projectile programmer 54.

[0077] The initial commutation in the system of FIG. 3B is based on an algorithm or table 12C, identifying an elevation solution 22C. The table (left top) identifies the theoretical elevation for a 40 mm AGL cartridge where the solution is derived from a firing table.

[0078] FIG. 3C is a process flow diagram illustrating the remote weapon station's control sequencing when firing volleys V, with control sub-routines identified. The exit velocity of the first volley V1 is measured at 52 and a fire control computer 12B then calculates a fire control solution 12C based on an algorithm that uses a default muzzle velocity. When firing a second volley V2, an alternative fire control algorithm 12D re-adjusts the elevation 22B.

[0079] FIG. 3D shows a system in which the muzzle velocity of an initial volley is measured at 52A and a fire control computer 12, using measured velocity V1, re-adjusts the weapon and mechanical support 18 to a second elevation solution. This system relies on a histogram of prior shot muzzle velocity data stored in the fire control memory.

[0080] FIGS. 4A, 4B, 4C, 4D and 4E depict an alternative embodiment of the invention having a manually-elevated mounted weapon 18, with a display 08, connected to a fire control system 12D with a projectile velocity measurement sensor 52, where the system includes external range-finding binoculars with a data link 06A (either galvanic or wireless). This system may fire conventional cartridges 60 as depicted in FIG. 4A or programmable cartridges 64A, 64B and 64D as depicted in FIGS. 4D, 4E and 4F. FIG. 4F, similar to FIG. 2D, depicts the sequencing of firing the manually-elevated weapon with an in-bore muzzle velocity measurement and programmer 54D.

[0081] Range-finding binoculars with a data link output (for example, Bluetooth wireless or an RS232 cable connection) that are suitable for use with this system are available commercially. Examples are:

1. Zeiss Victory 1045 T RF range-finding binoculars (with laser ballistic information systemBIS);
2. Nikon Laser force 1042 mm range-finding binoculars (with a 905 nm laser range finder);
3. Leica Geovid 1046/1056 range-finder binoculars;
4. Steiner 830 military LRF binoculars (with laser range-finder and RS232 cable output for a galvanic interface connection); and
5. Newcon Optik LRB 4000 CI laser range-finder binoculars with an RS232 cable output interface.

[0082] The binoculars are used manually to determine range to the target and transmit the range to the fire control system 12D.

[0083] There has thus been shown and described a novel method and apparatus for improving the aim of a remote weapon station (RWS), when firing either a point-detonating or a programmable air-burst projectile, that fulfills all of the objects and advantages sought therefor. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification and the accompanying drawings which disclose the preferred embodiments thereof. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is to be limited only by the claims which follow.

LIST OF REFERENCE NUMBERS

[0084] Ground Mount Configuration [0085] 06 Binoculars [0086] 06A Binoculars with a data link [0087] 08 Dismounted Aim Data Display [0088] RWS Configuration [0089] Remote Weapon Station [0090] 12 Fire Control Unit [0091] 12A Ballistic calculator in fire control [0092] 12B Memory (Histogram) in fire control [0093] 12C Algorithm or Table with assumed muzzle velocity [0094] 12D Algorithm using measured muzzle velocity [0095] 12E Preliminary Elevation Indicator [0096] 12F Adjusted Elevation Indicator [0097] Common Sub-Systems [0098] 16 (Human) Input Means [0099] 18 Weapon Mounted on Mechanical Support [0100] Spatial Position, Ballistics and Target Engagement [0101] 22 Elevation [0102] 22A Theoretical Elevation [0103] 22B Sensor Adjusted Elevation [0104] 26 Threat Detection System [0105] Level Target [0106] 42 Elevated Target [0107] 44 Trajectory [0108] 44a Level Trajectory [0109] 44b Elevated Trajectory [0110] 44c Elevation Adjusted for Exit Velocity [0111] 44mva Trajectory with a muzzle velocity 1 sigma less than the mean [0112] 44mv0 Trajectory with a muzzle velocity equal to the mean [0113] 44mvb Trajectory with a muzzle velocity 1 sigma greater than the mean [0114] 44mvi Improved Aim and Trajectory of 2.sup.nd volley [0115] T1 Programmed Time 1 sans exit velocity measurement [0116] T2 Programmed Time 1 adjusting for measured projectile exit velocity [0117] P1 Probability of Missing a Target [0118] P2 Probability of Hitting a Target [0119] MV Mean Theoretical Muzzle Velocity Used by Fire Control [0120] Improved System Sequence of Operation [0121] V1 1.sup.st Volley using a theoretical muzzle velocity [0122] V2 2.sup.nd Volley using sensor measured muzzle velocity from 1.sup.st volley [0123] V3 3.sup.rd Volley using sensor measured muzzle velocity from 2.sup.nd volley [0124] New Sensors and Emitters [0125] 52 Projectile Measurement Sensor [0126] 52A Muzzle Exit (Velocity) [0127] 52B Radar [0128] 52C Position Beacon [0129] 54 Programmer [0130] 54A Optical Programmer [0131] 54B RF or XMI Programmer [0132] 54C AHEAD Type Programmer [0133] Projectile Programming Methodology [0134] 60 Projectile [0135] 62 Conventional Projectile [0136] 64 Programmable Air-Burst Projectile [0137] 64A Optically programmed air-burst projectile [0138] 64B RF or XMI programmed air-burst projectile [0139] 64C AHEAD type air-burst projectile [0140] 66 Unfired Ammunition Cartridge with a projectile [0141] 68 Ammunition Can or Package