Method and apparatus for three dimensional wavenumber-frequency analysis

• US 9,453,900 B2
• Filed: 03/15/2013
• Issued: 09/27/2016
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: MacGillivray, John R., Graham, David L., Reiner, Dane E.
• Primary Examiner(s): Ratcliffe, Luke
• Assistant Examiner(s): Ndure Jobe, Amienatta M
• Application Number:
  US13/838,016
• Publication Number:
  US 20140269197A1
• Time in Patent Office: 1,292 Days
• Field of Search: 367/119, 367/8, 367/129, 702/14
• US Class Current: 1/1
• CPC Class Codes: G01S 3/80 using ultrasonic, sonic or infrasonic waves
• CPC Class Codes: G01S 3/86 with means for eliminating undesired waves, e.g. disturbing noises

Abstract

A method and apparatus for identifying an unidentified sound source in a 3-dimensional sensor array calculates a position vector for each of a plurality of sensors in the array. A time Fourier transform is computed based on time samples from each of the sensors. A spatial Fourier transform is computed for the results of the time Fourier transform and in part on the position vectors calculated. All three dimensional components of the wavenumber of the received signal, k_x, k_y and k_z are explicitly calculated to generate spatial frequency information in all three dimensions. Direction of arrival of the received sound signal is determined in all three spatial directions providing unambiguous target localization and acoustic signature characterization.

Claims

1. A method of computing wavenumber-frequency spectra comprising:

computing in a sonar array processor, a position vector for each sensor in a three-dimensional array of sensors, each position vector representative of a coordinate position of a corresponding sensor on a geometric surface defined by the three-dimensional array of sensors, in three orthogonal directions;

computing in the sonar array processor, a time Fourier transform on data from each said sensor in the array of sensors;

computing, in the sonar array processor, a spatial Fourier transform based in part on each computed position vector; and

outputting by the sonar array processor, results of said spatial Fourier transform, which is indicative of three-dimensional signal data received by said three-dimensional array of sensors,

wherein each position vector is computed according to;

2. The method of claim 1, wherein said three-dimensional sensor array is configured as a cylindrical array.

3. The method of claim 1 wherein said time Fourier transform on the data from each sensor is computed according to:

4. The method of claim 1 wherein said spatial Fourier transform is computed according to:

5. A three-dimensional sensor array for receiving wave energy data comprising:

a plurality of sensors, wherein a position of each said sensor with respect to a geometric surface defined by said sensor array defines a sensor coordinate position in three orthogonal dimensions;

a sensor array processor coupled to said sensor array, said processor configured to receive said sensor coordinate position and wave energy data from each sensor in said plurality of sensors, said processor further configured to compute a position vector for each sensor in the plurality of sensors based on each sensor'"'"'s coordinate position, and compute spatial wavenumber frequency spectra based at least in part on the computed position vectors, wherein said position vectors are computed according to;

6. The sensor array of claim 5, wherein said sensor array is configured as a cylindrical sonar array.

7. The sensor array of claim 5, wherein computing wavenumber frequency spectra further comprises:

receiving at the sensor array processor, the sensor coordinate positions for each sensor in the sensor array and computing a position vector for each sensor;

performing a time Fourier transform on data from each sensor; and

performing a spatial Fourier transform based at least in part on the position vector of each sensor of the plurality of sensors.

8. The sensor array of claim 7, wherein performing a time Fourier transform on the data is according to:

9. The sensor array of claim 7, wherein performing a spatial Fourier transform is according to:

10. A method of identifying sound sources in a three-dimensional sonar array comprising:

receiving an unidentified sound source signal via at least one of a plurality of sensors disposed on a surface defined by said three-dimensional sonar array;

defining a corresponding position vector for each sensor of said plurality of sensors based on a coordinate position of each sensor in three dimensions;

performing a time Fourier transform on time samples received at each of said plurality of sensors;

performing a spatial Fourier transform based at least in part on the position vector of each of said plurality of sensors;

analyzing the wavenumber and frequency of said unidentified sound source signal to determine an acoustic signature associated with said unidentified sound; and

identifying said sound source based on said acoustic signature wherein each position vector is computed according to;

11. The method of claim 10, wherein determining said acoustic signature comprises determining a speed of propagation of said sound source.

12. The method of claim 10, wherein said unidentified sound source is self noise.

13. A sonar array for providing three dimensional sensor data comprising:

a plurality of sensors disposed on a surface of said three dimensional sonar array, said surface defining a geometric surface area;

a processor configured to;

receive data from each of said plurality of sensors;

compute a position vector for each sensor of said plurality of sensors based on a coordinate position of each corresponding sensor in three dimensions with respect to said geometric surface area according to;

14. The sonar array of claim 13, wherein said geometric surface area is cylindrical.

15. The sonar array of claim 13, where said time Fourier transform is computed according to:

16. The sonar array of claim 13, wherein said spatial Fourier transform is computed according to:

17. A three-dimensional sensor array for receiving wave energy data comprising:

a plurality of sensors, wherein a position of each said sensor with respect to a geometric surface defined by said sensor array defines a sensor coordinate position in three orthogonal dimensions;

a sensor array processor coupled to said sensor array said processor configured to receive said sensor coordinate position and wave energy data from each sensor in said plurality of sensors, said processor further configured to compute a position vector for each sensor in the plurality of sensors based on each sensor'"'"'s coordinate position, and compute spatial wavenumber frequency spectra based at least in part on the computed position vectors, according to;

18. A method of identifying sound sources in a three-dimensional sonar array comprising:

receiving an unidentified sound source signal via at least one of a plurality of sensors disposed on a surface defined by said three-dimensional sonar array;

defining a corresponding position vector for each sensor of said plurality of sensors based on a coordinate position of each sensor in three dimensions;

performing a time Fourier transform on time samples received at each of said plurality of sensors according to;