Partially coherent beamformer for sparse, irregular arrays

• US 6,509,871 B2
• Filed: 02/02/2001
• Issued: 01/21/2003
• Est. Priority Date: 02/04/2000
• Status: Expired due to Fees

• Current Assignee: General Dynamics Information Systems, Inc. (General Dynamics Corporation)
• Original Assignee: General Dynamics Information Systems, Inc. (General Dynamics Corporation)
• Inventors: Bevington, James E.
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US09/776,282
• Publication Number:
  US 20020105464A1
• Time in Patent Office: 718 Days
• Field of Search: 342/357.09, 342/357.1, 342/373, 342/375, 367/20, 367/62
• US Class Current: 342/373
• CPC Class Codes: G01V 1/20 Arrangements of receiving elements, e.g. geophone pattern
• CPC Class Codes: G01V 1/223 Radioseismic systems
• CPC Class Codes: G10K 11/34 using electrical steering of transducer arrays, e.g. beam steering constructional aspects B06B1/0607, B06B1/085
• CPC Class Codes: G10K 11/341 Circuits therefor
• CPC Class Codes: H01Q 21/22 Antenna units of the array energised non-uniformly in amplitude or phase, e.g. tapered array or binomial array
• CPC Class Codes: H01Q 3/22 varying the orientation in accordance with variation of frequency of radiated wave
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence

Abstract

A system and method for beamforming signals received in sparse, irregular sensor arrays has a network of sensors organized into sensor clusters, a signal processing node for each sensor cluster for beamforming the signals received by the sensors in each sensor cluster and an aggregation node for combining the beamformed responses from each sensor cluster to form a composite response characterized by minimized side lobes and grating lobes.

Claims

1. A beamforming system, comprising:

a plurality of sensors for receiving signals, said sensors organized into at least one sensor cluster, wherein each said sensor cluster includes at least one of said sensors;

at least one signal processing node for each said sensor cluster for beamforming signals received by said at least one sensor in said at least one sensor cluster;

at least one aggregation node for determining a composite response of said beamformed signals;

a plurality of sensor links for transmitting signals received by said plurality of sensors from said plurality of sensors to said at least one signal processing node; and

at least one signal processing node link for transmitting from said at least one signal processing node said beamformed signals to said at least one aggregation node.

2. The beamforming system of claim 1 wherein said plurality of sensors are multi-signal sensors.

3. The beamforming system of claim 1 wherein said plurality of sensors are acoustic sensors.

4. The beamforming system of claim 1 wherein said plurality of sensors are sonar sensors.

5. The beamforming system of claim 1 wherein said plurality of sensors are radar sensors.

6. The beamforming system of claim 1 wherein said plurality of sensors each include a global positioning system receiver.

7. The beamforming system of claim 1 wherein said plurality of sensor links are wire connectors.

8. The beamforming system of claim 7 wherein said plurality of sensors each include a global positioning system receiver.

9. The beamforming system of claim 8 wherein said aggregation node includes an aggregation node radio transceiver, wherein said at least one signal processing node includes a multi-channel radio transceiver, and wherein said at least one signal processing node link uses radio frequency transmission between said multi-channel radio transceiver and said aggregation node radio transceiver.

10. The beamforming system of claim 1 wherein said plurality of sensors each include sensor radio transceivers, wherein said at least one signal processing node includes a multi-channel radio transceiver, and wherein said plurality of sensor links use radio frequency transmissions between said sensor radio transceivers and said multi-channel radio transceiver.

11. The beamforming system of claim 10 wherein said at least one signal processing node link is a wire connection.

12. The beamforming system of claim 10 wherein said plurality of sensors each include a global positioning system receiver.

13. The beamforming system of claim 12 wherein said at least one signal processing node link is a wire connection.

14. The beamforming system of claim 10 wherein said aggregation node includes an aggregation node radio transceiver, wherein said at least one signal processing node includes a multi-channel radio transceiver, and wherein said at least one signal processing node link uses radio frequency transmission between said multi-channel radio transceiver and said aggregation node radio transceiver.

15. The beamforming system of claim 1 wherein said at least one signal processing node link is a wire connection.

16. The beamforming system of claim 15 wherein said plurality of sensors each include a global positioning system receiver.

17. The beamforming system of claim 1 wherein said aggregation node includes an aggregation node radio transceiver, wherein said at least one signal processing node includes a multi-channel radio transceiver, and wherein said at least one signal processing node link uses radio frequency transmission between said multi-channel radio transceiver and said aggregation node radio transceiver.

18. The beamforming system of claim 17 wherein said plurality of sensors each include a global positioning system receiver.

19. A beamforming system, comprising:

a plurality of sensors for receiving signals, said sensors organized into at least one sensor cluster, wherein each said sensor cluster includes at least one of said sensors, each said sensor including;

(a) a global positioning system receiver for determining the positions of said sensor, and

(b) a sensor radio transceiver;

at least one signal processing node for beamforming signals received by said plurality of sensors, said signal processing node including a multi-channel radio transceiver;

at least one aggregation node for determining a composite response of said beamformed signals, said at least one aggregation node including an aggregation node radio transceiver;

a plurality of sensor links for transmitting signals received by said plurality of sensors by radio frequency transmission between said sensor radio transceivers and said multi-channel radio transceiver; and

at least one signal processing node link for transmitting said beamformed signals by radio frequency transmission between said multi-channel radio transceiver and said aggregation node radio transceiver.

20. A method for beamforming, comprising the steps of:

deploying a plurality of sensors in an area;

determining the relative positions of the sensors;

organizing the plurality of sensors into at least one sensor cluster wherein each sensor cluster includes at least one sensor;

detecting signals in the sensors;

creating beamformed responses by beamforming the signals detected by the sensors in each sensor cluster, wherein the signals detected by the sensors in each sensor cluster are beamformed independently of the signals detected in other sensor clusters;

creating a composite response of all the beamformed responses by combining the beamformed responses together.

21. The method for beamforming of claim 20 wherein said creating beamformed responses is by delay and sum beamforming.

22. The method of beamforming of claim 20 wherein said creating beamformed responses is by Fast Fourier Transform beamforming.

23. The method for beamforming of claim 20 wherein said determining the relative positions of the sensors step is accomplished by carrier phased based global positioning.

24. The method of beamforming of claim 23 wherein said creating beamformed responses is by delay and sum beamforming.

25. The method of beamforming of claim 23 wherein said creating beamformed responses is by Fast Fourier Transform beamforming.

26. The method for beamforming of claim 20 wherein said creating a composite response step includes the step of multiplying the beamformed responses together such that the composite response, X(k), is:

27. The method for beamforming of claim 26 wherein said determining the relative positions of the sensors step is accomplished by carrier phased based global positioning.

28. The method for beamforming of claim 27 wherein said creating beamformed responses is by delay and sum beamforming.

29. The method for beamforming of claim 27 wherein said creating beamformed responses is by Fast Fourier Transform beamforming.

30. The method for beamforming of claim 26 wherein said creating beamformed responses is by delay and sum beamforming.

31. The method for beamforming of claim 26 wherein said creating beamformed responses is by Fast Fourier Transform beamforming.

32. The method for beamforming of claim 26 wherein said creating a composite response step further includes the step of pre-editing the beamformed responses prior to said multiplying step by removing those beamformed responses that have the highest and lowest magnitudes.

33. The method for beamforming of claim 32 wherein said determining the relative positions of the sensors step is accomplished by carrier phased based global positioning.

34. The method for beamforming of claim 33 wherein said creating beamformed responses is by delay and sum beamforming.

35. The method for beamforming of claim 33 wherein said creating beamformed responses is by Fast Fourier Transform beamforming.

36. The method for beamforming of claim 32 wherein said creating beamformed responses is by delay and sum beamforming.

37. The method for beamforming of claim 32 wherein said creating beamformed responses is by Fast Fourier Transform beamforming.

38. The method for beamforming of claim 20 wherein said creating a composite response step includes the steps of performing a low order statistic on each of the beamformed responses, and using the results obtained from said low order statistic step to form the composite response.

39. The method for beamforming of claim 38 wherein said determining the relative positions of the sensors step is accomplished by carrier phased based global positioning.

40. The method for beamforming of claim 39 wherein said creating beamformed responses is by delay and sum beamforming.

41. The method for beamforming of claim 39 wherein said creating beamformed responses is by Fast Fourier Transform beamforming.

42. The method for beamforming of claim 38 wherein said creating beamformed responses is by delay and sum beamforming.

43. The method for beamforming of claim 38 wherein said creating beamformed responses is by Fast Fourier Transform beamforming.