System and method for determining the location of an acoustic event

• US 7,233,545 B2
• Filed: 09/07/2005
• Issued: 06/19/2007
• Est. Priority Date: 09/08/2004
• Status: Expired due to Fees

• Current Assignee: Mcginn-Harvey Holdings LLC
• Original Assignee: Mcginn-Harvey Holdings LLC
• Inventors: McGinn, Jack, Harvey, Edward P. Jr.
• Primary Examiner(s): PIHULIC, DANIEL T
• Application Number:
  US11/221,541
• Publication Number:
  US 20060050610A1
• Time in Patent Office: 650 Days
• Field of Search: 367/5, 367/902, 367/128, 367/127, 367/906
• US Class Current: 367/127
• CPC Class Codes: G01S 5/22 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/28 takes precedence

Abstract

A system and method is provided for determining the three dimensional location of an acoustic event using a system of five or more sound sensing elements. The sensing elements are positioned at substantially the same elevation and in spatially distributed locations with respect to the acoustic event. The sensing elements generate notification signals indicating occurrence of the acoustic event. A central processor receives the notification signals, associates the locations of each of the sensing elements with the time at which each sensing element sensed the sound, determines the speed of sound for the medium, and calculates a three dimensional location for the acoustic event using a linear error minimization algorithm. A system of six or more sensing elements enables the processor further to discriminate between near simultaneous acoustic events.

Claims

1. A system for determining the three dimensional location of an acoustic event producing sound in a medium, comprising:

five or more sensing elements at substantially the same elevation and in spatially distributed predetermined locations with respect to the acoustic event, for sensing sound in the medium and generating notification signals upon sensing sound from the acoustic event;

a processor;

a communication interface between the five or more sensing elements and the processor for communicating the notification signals from the five or more sensing elements to the processor; and

said processor is configured to determine the speed of sound in the medium and to calculate the three dimensional location of the acoustic event as a function of the times of generation of the notification signals and the respective predetermined locations of the five or more sensing elements, by using a linear minimization algorithm.

2. The system of claim 1, wherein said processor determines the speed of sound in the medium by using the notification signals from at least two of the five or more sensing elements.

3. The system of claim 1, wherein:

each of the five or more sensing elements further include a transmitter for transmitting notification signals; and

the communication interface includes a receiver for receiving notification signals and communicating the notification signals to the processor.

4. The system of claim 1 further comprising a timer for generating a time signal and providing the time signal to the processor.

5. The system of claim 1, further comprising

at least one sensing element in addition to the five or more sensing elements where said at least one sensing element is at substantially the same elevation as the five or more sensing elements and in a spatially distributed predetermined location with respect to the acoustic event, for sensing sound in the medium and generating notification signals upon sensing sound from an acoustic event;

and

said processor is further configured to determine three dimensional locations in the medium of two near simultaneous acoustic events comprising a first acoustic event and a second acoustic event, by determining a three dimensional location for the first acoustic event using a linear minimization algorithm and the times at which each of the five or more sensing elements in their respective predetermined locations sensed the sound of the two near simultaneous acoustic events, and associating notification signals with the first acoustic event, and by determining for the second acoustic event a three dimensional location by using a linear minimization algorithm and the times at which each of the five or more sensing elements in their respective predetermined locations sensed the sound of the two near simultaneous acoustic events excluding the notification signals associated with the first acoustic event.

6. The system of claim 1, wherein:

said acoustic event is a detonation of a projectile fired from a gun having a gun fire control system, wherein the gun fire control system generates a gun order time signal associated with the acoustic event;

the gun fire control system is communicably linked to a communication system for communicating the gun order time signal to the processor; and

said processor is further configured to determine three dimensional locations in the medium of two near simultaneous acoustic events comprising a first acoustic event and a second acoustic event by associating notification signals with a first gun order time signal for the first acoustic event and associating notification signals with a second gun order time signal for the second acoustic event, and determining the three dimensional location for each of the two near simultaneous acoustic events as a function of the notification signals associated with that acoustic event and the predetermined locations of the five or more sensing elements, by using a linear minimization algorithm.

7. A system for determining the three dimensional location of an acoustic event producing sound in a medium, comprising:

five or more sensing elements at substantially the same elevation and in spatially distributed locations with respect to the acoustic event, for sensing sound in the medium and generating notification signals upon sensing sound from the acoustic event;

a processor;

a positioning system capable of determining the location of each of the five or more sensing elements, generating one or more location signals having location information of the five or more sensing elements, and providing the location signal to the processor;

a communication interface between the five or more sensing elements and the processor for communicating the notification signals from the five or more sensing elements to the processor; and

said processor is configured to determine the speed of sound in the medium and to calculate the three dimensional location of the acoustic event as a function of the times of generation of the notification signals and the respective locations of the five or more sensing elements, by using a linear minimization algorithm.

8. The system of claim 7, wherein said processor determines the speed of sound in the medium by using the notification signals from at least two of the five or more sensing elements and the corresponding location signals for the at least two of the five or more sensing elements.

9. The system of claim 7, wherein

each of the five or more sensing elements further include a transmitter for transmitting the notification signals;

and

the communication interface includes a receiver for receiving the notification signals and communicating the notification signals to the processor.

10. The system of claim 7, further comprising

at least one sensing element in addition to the five or more sensing elements where such at least one sensing element is at substantially the same elevation as the five or more sensing elements and in a spatially distributed location with respect to the acoustic event, for sensing sound in the medium and generating notification signals upon sensing sound from an acoustic event;

and

said processor is further configured to determine three dimensional locations in the medium of two near simultaneous acoustic events comprising a first acoustic event and a second acoustic event, by determining a three dimensional location for the first acoustic event using a linear minimization algorithm and the times at which each of the five or more sensing elements in their respective locations sensed the sound of the two near simultaneous acoustic events, and associating notification signals with the first acoustic event, and by determining for the second acoustic event a three dimensional location by using a linear minimization algorithm and the times at which each of the five or more sensing elements in their respective locations sensed the sound excluding the notification signals associated with the first acoustic event.

11. The system as set forth in claim 7, wherein said medium is water, and wherein at least one of said five or more sensor elements is attached to a buoy.

12. The system as set forth in claim 7, wherein said positioning system includes at least one global positioning satellite receiver.

13. The system as set forth in claim 7, wherein said positioning system includes radar.

14. The system as set forth in claim 7, wherein said positioning system is optical.

15. The system of claim 7, wherein:

said acoustic event is a detonation of a projectile fired from a gun having a gun fire control system, wherein the gun fire control system generates a gun order time signal associated with the acoustic event;

the gun fire control system is communicably linked to a communication system for communicating the gun order time signal to the processor; and

said processor is further configured to determine three dimensional locations in the medium of two near simultaneous acoustic events comprising a first acoustic event and a second acoustic event by associating notification signals with a first gun order time signal for the first acoustic event and associating notification signals with a second gun order time signal for the second acoustic event, and determining the three dimensional location for each of the two near simultaneous acoustic events as a function of the notification signals associated with that acoustic event and the locations of the five or more sensing elements, by using a linear minimization algorithm.

16. A method for determining the three dimensional location of an acoustic event producing sound waves in a medium, comprising:

sensing sound waves of the acoustic event from at least five locations that are at substantially the same elevation and are spatially distributed with respect to the acoustic event;

determining the at least five locations from which the sound waves are sensed;

recording the time at which the sound waves are sensed at each of the at least five locations;

determining the speed of sound in the medium;

associating the time of sensing the sound waves with the location of each of the at least five locations; and

determining the three dimensional location of the acoustic event as a function of the at least five locations and the times of sensing sound waves of the acoustic event at the at least five locations, using a linear minimization algorithm.

17. The method according to claim 16, wherein:

the step of determining the speed of sound in a medium is a function of the distance between at least two of the at least five locations and the difference in their respective times of sensing sound waves from an acoustic event.

18. A method for determining the three dimensional locations of two near simultaneous acoustic events having a first acoustic event and a second acoustic event, each producing sound waves in a medium, comprising:

sensing sound waves of the two near simultaneous acoustic events from at least six locations that are at substantially the same elevation and are spatially distributed with respect to the acoustic event;

determining the at least six locations from which the sound waves are sensed;

recording the time at which the sound waves are sensed at each of the at least six locations;

determining the speed of sound in the medium;

associating the times of sensing the sound waves with the location of each of the at least six locations;

determining a three dimensional location for the first acoustic event as a function of the at least six locations and the times of sensing sound waves of the acoustic events at the at least six locations, using a linear minimization algorithm, and associating notification signals with the first acoustic event; and

determining for the second acoustic event a three dimensional location as a function of, excluding the times of sensing and locations associated with the first acoustic event, the at least six locations and the times of sensing sound waves of the acoustic events at the at least six locations, using a linear minimization algorithm.

19. The method according to claim 18, wherein:

the step of determining the speed of sound in a medium is a function of the distance between at least two of the at least six locations and the difference in their respective times of sensing sound waves from an acoustic event.