System and method for locating a trajectory and a source of a projectile

• US 5,781,505 A
• Filed: 10/14/1997
• Issued: 07/14/1998
• Est. Priority Date: 10/14/1997
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Rowland, Raymond J.
• Primary Examiner(s): Lobo, Ian J.
• Application Number:
  US08/954,094
• Time in Patent Office: 273 Days
• Field of Search: 367/118, 367/124, 367/127, 367/906
• US Class Current: 367/127
• CPC Class Codes: F41J 5/06 Acoustic hit-indicating systems, i.e. detecting of shock waves F41J5/056 takes precedence
• CPC Class Codes: F41J 5/10 Cinematographic hit-indicating systems cinematographic targets F41J9/14
• CPC Class Codes: G01S 5/18 using ultrasonic, sonic, or infrasonic waves
• CPC Class Codes: Y10S 367/906 Airborne shock-wave detection

Abstract

A projectile trajectory and source location system and method identifies, calizes, and displays a projectile trajectory relative to one or more stationary objects, such as buildings in an urban environment. The system includes a sensor array and trajectory location calculator that sense conditions generated by the projectile, such as an acoustic signature, and calculate a set of ranges to the trajectory. A ranging system and range comparison calculator measure ranges to one or more stationary objects and compare those ranges to the set of ranges to the trajectory. A display displays the trajectory relative to the stationary objects including unobstructed portions of the trajectory, obstructed portions of the trajectory and the located source of the projectile. A tracking system and dynamic reprocessor track the movement of an observer, dynamically reprocess the relative trajectory location, and update the display of the relative trajectory location in response to the observer'"'"'s movement.

Claims

1. A system for locating a trajectory of a projectile relative to at least one stationary object, said system comprising:

an acoustic sensor, for sensing conditions generated by said projectile;

a trajectory location calculator, responsive to said sensed conditions from said acoustic sensor, for calculating a set of ranges to said trajectory;

a ranging system, responsive to said trajectory location calculator, for determining a range to said at least one stationary object along said trajectory of said projectile; and

a range comparison calculator, responsive to said trajectory location calculator and said ranging system, for comparing said set of ranges to said trajectory and said range to said at least one stationary objects for determining a trajectory location of said projectile relative to said at least one stationary object.

2. The system of claim 1 further including a display, responsive to said trajectory location calculator and said range comparison calculator, for displaying said trajectory relative to said at least one stationary object.

3. The system of claim 2 further including:

a tracking system, for tracking movement of an observer; and

a dynamic reprocessor, responsive to said range comparison calculator and said tracking system, for reprocessing said trajectory location in response to said movement of said observer.

4. The system of claim 3 wherein said tracking system includes a global positioning system, for tracking a change in location of said observer, and wherein said dynamic reprocessor updates said trajectory of said projectile on said display in response to said change in location of said observer.

5. The system of claim 3 wherein said tracking system includes a head tracking system, for tracking head movement of said observer;

and wherein said dynamic reprocessor dynamically updates said trajectory on said display in response to said head movement of said observer.

6. The system of claim 3 wherein said trajectory location calculator, said range comparison calculator, and said dynamic reprocessor are implemented on at least one central processing unit.

7. The system of claim 3 wherein said display includes a heads-up display held on a head of a viewer.

8. The system of claim 7 wherein said heads-up display includes a light transmissive liquid crystal display (LCD).

9. The system of claim 1 wherein said acoustic sensor comprises an array of pressure sensors, and wherein said conditions sensed by said acoustic sensor array include pressure changes caused by a shock wave generated by said projectile.

10. A method of locating a trajectory of and a source of a projectile relative to at least one stationary object, said method comprising the steps of:

sensing conditions generated by said projectile as said projectile travels from said source;

calculating a set of ranges to said trajectory of said projectile using said sensed conditions, said set of ranges to said trajectory representing a trajectory path;

calculating a range to said at least one stationary object along said trajectory of said projectile; and

comparing said set of ranges to said trajectory and said range to said at least one stationary object, for determining a trajectory location relative to said at least one stationary object, and for determining said source of said projectile.

11. The method of claim 10 wherein determining said source of said projectile includes determining a point along said trajectory location where said range to said trajectory is substantially equal to said range to said at least one stationary object.

12. The method of claim 10 further including the step of displaying said trajectory on a display.

13. The method of claim 10 further including the step of, after comparing said set of ranges to said trajectory and said range to said at least one stationary object, displaying said trajectory on a display relative to said at least one stationary object.

14. The method of claim 13 wherein determining said relative trajectory location relative to said at least one stationary object includes determining an unobstructed portion of said trajectory along which said range to said trajectory is less than said range to said at least one stationary object.

15. The method of claim 14 wherein determining said relative trajectory location relative to said at least one stationary object further includes determining an obstructed portion of said trajectory along which said range to said trajectory is greater than said range to said at least one stationary object.

16. The method of claim 15 wherein displaying said trajectory relative to said at least one stationary object includes displaying said obstructed portion of said trajectory and said unobstructed portion of said trajectory using different formats.

17. The method of claim 13 further including the steps of:

tracking movement of an observer observing said trajectory on said display; and

responsive to movement of said observer, dynamically updating said trajectory on said display relative to said movement of said observer.

18. The method of claim 17 wherein the step of tracking movement of said observer includes tracking a change in location of said observer with a global positioning system.

19. The method of claim 17 wherein the step of tracking movement of said observer includes tracking head movement of said observer.

20. The method of claim 10 wherein the step of sensing conditions generated by said projectile includes sensing acoustic pressure changes caused by a shock wave generated by said projectile.