Full polarization ground moving target indicator radar automatic target detection algorithm

• US 6,756,935 B1
• Filed: 01/31/2003
• Issued: 06/29/2004
• Est. Priority Date: 01/31/2003
• Status: Expired due to Fees

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Curry, Mark A., Cameron, William L.
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): ANDREA, BRIAN K
• Application Number:
  US10/356,224
• Time in Patent Office: 515 Days
• Field of Search: 342/28, 342/90, 342/160, 342/161, 342/25
• US Class Current: 342/90
• CPC Class Codes: G01S 13/5244 Adaptive clutter cancellation specially adapted for airborne MTI, G01S13/5242
• CPC Class Codes: G01S 7/024 using polarisation effects in waveguides H01P1/165; for aerials H01Q, e.g. H01Q15/22, H01Q15/24, H01Q19/195
• CPC Class Codes: G01S 7/414 Discriminating targets with respect to background clutter

Abstract

A method, apparatus, and system for automatic detection of targets from radar data are disclosed. Ground moving target indicator radar is used to collect radar data which is then filtered to suppress intensity of the clutter ridge. For each working point in a set of radar data, a working first-sense circular transmit/first-sense circular receive radar cross section, a working first-sense circular transmit/second-sense circular receive radar cross section, and a working asymmetry angle are calculated from a scattering matrix, then analyzed to classify the working point as a target point or a clutter point. This analysis suitably is performed by comparing data calculated for each working point to basis data collected in a look-up table in which combinations of a first-sense circular transmit/first-sense circular receive radar cross section, a first-sense circular transmit/second-sense circular receive radar cross section, and an asymmetry angle have been classified as target points or clutter points.

Claims

1. A method for detecting targets in radar signals, the method comprising:

suppressing a clutter ridge appearing in a working radar data;

calculating for a plurality of working points in the working radar data a working first-sense circular transmit/first-sense circular receive radar cross-section, a working first-sense circular transmit/second-sense circular receive radar cross-section, and a working asymmetry angle from a working scattering matrix; and

comparing each of the plurality of working points to determine whether the working first-sense circular transmit/first-sense circular receive radar cross-section, the working first-sense circular transmit/second-sense circular receive radar cross-section, and the working asymmetry angle indicate the working points constitute target points or clutter points.

2. The method of claim 1, further comprising the step of creating a look-up table, the look-up table associating combinations of a first-sense circular transmit/first-sense circular receive radar cross-section, a first-sense circular transmit/second-sense circular receive radar cross-section, and an asymmetry angle as representing target points and clutter points such that the working first-sense circular transmit/first-sense circular receive radar cross-section, the working first-sense circular transmit/second-sense circular receive radar cross-section, and the working asymmetry angle can be looked up in the look-up table to classify the working point as a target point or a clutter point.

3. The method of claim 1, further comprising collecting the working data for a working area of interest.

4. The method of claim 3, wherein the working radar data for the area of interest is collected using ground moving target indicator radar.

5. The method of claim 4, wherein the working data comprises range and Doppler working radar data.

6. The method of claim 1, wherein the suppressing of the clutter ridge is accomplished with filtering.

7. The method of claim 6, wherein the filtering applied to suppress the clutter ridge in the working radar data includes space-time adaptive processing.

8. The method of claim 7, wherein the filtering applied to suppress the clutter ridge in the working radar data includes joint domain localized space-time adaptive processing.

9. The method of claim 1, wherein the first-sense is a left-sense and the second-sense is a right-sense.

10. The method of claim 1, wherein the first-sense is a right-sense and the second-sense is a left-sense.

11. The method of claim 1, wherein the working scattering matrix is derived from working vertical single pole data, working horizontal single pole data, and working cross pole data, the working cross pole data including at least one of a working vertical transmit and horizontal receive scan or a working horizontal transmit and vertical receive scan.

12. The method of claim 1, wherein the working scattering matrix is derived from working vertical single pole data, working horizontal single pole data, and working cross pole data, the working cross pole data including a working vertical transmit and horizontal receive scan and a working horizontal transmit and vertical receive scan.

13. A method for detecting targets in radar signals, the method comprising:

suppressing a clutter ridge appearing in a basis radar data;

calculating for a plurality of basis points in the basis radar data a first-sense circular transmit/first-sense circular receive radar cross-section, a first-sense circular transmit/second-sense circular receive radar cross-section, and an asymmetry angle from a basis scattering matrix;

generating the look-up table of the first-sense circular transmit/first-sense circular receive radar cross-section, the first-sense circular transmit/second-sense circular receive radar cross-section, and the asymmetry angle for the plurality of points in the basis radar data; and

classifying in the look-up table combinations of the first-sense circular transmit/first-sense circular receive radar cross-section, the first-sense circular transmit/second-sense circular receive radar cross-section, and the asymmetry angle as target points and clutter points.

14. The method of claim 13, further comprising collecting basis radar data for a representative area of interest.

15. The method of claim 14, wherein the basis radar data for the representative area of interest is collected using ground moving target indicator radar.

16. The method of claim 15, wherein the basis radar data comprises range and Doppler basis radar data.

17. The method of claim 13, wherein the suppressing of the clutter ridge is accomplished with filtering.

18. The method of claim 17 wherein the filtering applied to suppress the clutter ridge in the basis radar data includes space-time adaptive processing.

19. The method of claim 18, wherein the filtering applied to suppress the clutter ridge in the basis radar data includes joint domain localized space-time adaptive processing.

20. The method of claim 13, wherein the first-sense is a left-sense and the second-sense is a right-sense.

21. The method of claim 13, wherein the first-sense is a right-sense and the second-sense is a left-sense.

22. The method of claim 13, wherein the basis scattering matrix is derived from basis vertical single pole data, basis horizontal single pole data, and basis cross pole data, the basis cross pole data including at least one of a basis vertical transmit and horizontal receive scan or a basis horizontal transmit and vertical receive scan.

23. The method of claim 13, wherein the basis scattering matrix is derived from basis vertical single pole data, basis horizontal single pole data, and basis cross pole data, the basis cross pole data including a basis vertical transmit and horizontal receive scan and a basis horizontal transmit and vertical receive scan.

24. The method of claim 13, wherein the identifying of the target points and the clutter points in the look-up table is derived manually by comparing the basis radar data for the representative area of interest with predetermined data.

25. The method of claim 13, wherein the identifying of the target points and the clutter points in the look-up table is manually adjusted to classify predetermined clutter points.

26. A method for detecting targets in radar signals, the method comprising:

suppressing a clutter ridge appearing in a basis radar data;

calculating for a plurality of basis points in the basis radar data a first-sense circular transmit/first-sense circular receive radar cross-section, a first-sense circular transmit/second-sense circular receive radar cross-section, and an asymmetry angle from a basis scattering matrix;

generating the look-up table of the first-sense circular transmit/first-sense circular receive radar cross-section, the first-sense circular transmit/second-sense circular receive radar cross-section, and the asymmetry angle for the plurality of points in the basis radar data; and

classifying in the look-up table combinations of the first-sense circular transmit/first-sense circular receive radar cross-section, the first-sense circular transmit/second-sense circular receive radar cross-section, and the asymmetry angle as target points and clutter points,

suppressing a clutter ridge appearing in a working radar data;

calculating for a plurality of working points in the working radar data a working first-sense circular transmit/first-sense circular receive radar cross-section, a working first-sense circular transmit/second-sense circular receive radar cross-section, and a working asymmetry angle from a working scattering matrix;

comparing each of the plurality of working points to a look-up table, the look-up table correlating combinations of a first-sense circular transmit/first-sense circular receive radar cross-section, a first-sense circular transmit/second-sense circular receive radar cross-section, and an asymmetry angle representing target points and clutter points; and

correlating working points with target points identified in the look-up table.

27. The method of claim 26, further comprising collecting the basis radar data for the representative area of interest.

28. The method of claim 27, wherein the basis radar data for the area of interest is collected using ground moving target indicator radar.

29. The method of claim 28, wherein the basis data comprises range and Doppler working radar data.

30. The method of claim 26, wherein the suppressing of the clutter ridge is accomplished with filtering.

31. The method of claim 30 wherein the filtering applied to suppress the clutter ridge in the basis radar data is space-time adaptive processing.

32. The method of claim 31, wherein the filtering applied to suppress the clutter ridge in the basis radar data is joint domain localized space-time adaptive processing.

33. The method of claim 26, wherein the first-sense is a left-sense and the second-sense is a right-sense.

34. The method of claim 26, wherein the first-sense is a right-sense and the second-sense is a left-sense.

35. The method of claim 26, wherein the basis scattering matrix is derived from basis vertical single pole data, basis horizontal single pole data, and basis cross pole data, the basis cross pole data including at least one of a basis vertical transmit and horizontal receive scan or a basis horizontal transmit and vertical receive scan.

36. The method of claim 26, wherein the basis scattering matrix is derived from basis vertical single pole data, basis horizontal single pole data, and basis cross pole data, the basis cross pole data including a basis vertical transmit and horizontal receive scan and a basis horizontal transmit and vertical receive scan.

37. The method of claim 26, wherein the identifying of the target points and the clutter points in the look-up table is derived manually by comparing the basis radar data for the representative area of interest with predetermined data.

38. The method of claim 26, wherein the identifying of the target points and the clutter points in the look-up table is manually adjusted to classify predetermined clutter points.

39. The method of claim 26, further comprising collecting the working data for a working area of interest.

40. The method of claim 39, wherein the working radar data for the area of interest is collected using ground moving target indicator radar.

41. The method of claim 40, wherein the working data comprises range and Doppler working radar data.

42. The method of claim 41, wherein the suppressing of the clutter ridge is accomplished with filtering.

43. The method of claim 42, wherein the filtering applied to suppress the clutter ridge in the working radar data is space-time adaptive processing.

44. The method of claim 43, wherein the filtering applied to suppress the clutter ridge in the working radar data is joint domain localized space-time adaptive processing.

45. The method of claim 26, wherein the working scattering matrix is derived from working vertical single pole data, working horizontal single pole data, and working cross pole data, the working cross pole data including at least one of a working vertical transmit and horizontal receive scan or a working horizontal transmit and vertical receive scan.

46. The method of claim 26, wherein the working scattering matrix is derived from working vertical single pole data, working horizontal single pole data, and working cross pole data, the working cross pole data including a working vertical transmit and horizontal receive scan and a working horizontal transmit and vertical receive scan.

47. A system for detecting targets in multiple polarization radar signals, the system comprising:

a radar transceiver operable to collect working radar data for a working area of interest;

a first filter configured to suppress a clutter ridge appearing in the working radar data;

a radar signal processor for calculating for a plurality of working points in the working radar data a working first-sense circular transmit/first-sense circular receive radar cross-section, a working first-sense circular transmit/second-sense circular receive radar cross-section, and a working asymmetry angle from a working scattering matrix; and

a comparator for comparing calculated values of the working first-sense circular transmit/first-sense circular receive radar cross-section, the working first-sense circular transmit/second-sense circular receive radar cross-section, and the working asymmetry angle for each of the plurality of working points in the working radar data to determine whether the working points constitute target points or clutter points.

48. The system of claim 47, wherein the working radar data for the area of interest is collected using ground moving target indicator radar.

49. The system of claim 48, wherein the working data comprises range and Doppler working radar data.

50. The system of claim 47, wherein the first filter employs space-time adaptive processing.

51. The system of claim 50, wherein the first filter employs joint domain localized space-time adaptive processing.

52. The system of claim 47, wherein the first-sense is a left-sense and the second-sense is a right-sense.

53. The system of claim 47, wherein the first-sense is a right-sense and the second-sense is a left-sense.

54. The system of claim 47, wherein the working scattering matrix is derived from working vertical single pole data, working horizontal single pole data, and working cross pole data, the working cross pole data including at least one of a working vertical transmit and horizontal receive scan or a working horizontal transmit and vertical receive scan.

55. The system of claim 47, wherein the working scattering matrix is derived from working vertical single pole data, working horizontal single pole data, and working cross pole data, the working cross pole data including a working vertical transmit and horizontal receive scan and a working horizontal transmit and vertical receive scan.

56. The system of claim 47, further comprising:

a collection of range and Doppler basis radar data for a representative area of interest;

a second filter configured to suppress a clutter ridge appearing in the basis radar data;

a look-up table processor for calculating for a plurality of basis points in the basis radar data a first-sense circular transmit/first-sense circular receive radar cross-section, a first-sense circular transmit/second-sense circular receive radar cross-section, and an asymmetry angle from a basis scattering matrix;

a look-up table generator creating the look-up table of the first-sense circular transmit/first-sense circular receive radar cross-section, the first-sense circular transmit/second-sense circular receive radar cross-section, and the asymmetry angle for the plurality of points in the basis radar data; and

a target identifier for classifying in the look-up table which combinations of the first-sense circular transmit/first-sense circular receive radar cross-section, the first-sense circular transmit/second-sense circular receive radar cross-section, and the asymmetry angle as target points and clutter points.

57. The system of claim 56, wherein the first-sense is a left-sense and the second-sense is a right-sense.

58. The system of claim 56, wherein the first-sense is a right-sense and the second-sense is a left-sense.

59. The system of claim 54, wherein the second filter uses space-time adaptive processing.

60. The system of claim 55, wherein the second filter uses joint domain localized space-time adaptive processing.

61. The system of claim 56, wherein the basis scattering matrix is derived from basis vertical single pole data, basis horizontal single pole data, and basis cross pole data, the basis cross pole data including at least one of a basis vertical transmit and horizontal receive scan or a basis horizontal transmit and vertical receive scan.

62. The system of claim 56, wherein the basis scattering matrix is derived from basis vertical single pole data, basis horizontal single pole data, and basis cross pole data, the basis cross pole data including a basis vertical transmit and horizontal receive scan and a basis horizontal transmit and vertical receive scan.

63. The system of claim 56, wherein the target identifier identifies the target points and the clutter points in the look-up table by comparing the basis radar data for the representative area of interest with predetermined data.

64. The system of claim 63, wherein the target identifier identifies the target points and the clutter points in the look-up table manually by classifying predetermined clutter points.

65. A computer readable medium having stored thereon instructions for detecting targets in radar signals, the instructions comprising:

instructions for suppressing a clutter ridge appearing in a working radar data;

instructions for calculating for a plurality of working points in the working radar data a working first-sense circular transmit/first-sense circular receive radar cross-section, a working first-sense circular transmit/second-sense circular receive radar cross-section, and a working asymmetry angle from a working scattering matrix; and

instructions for comparing each of the plurality of working points to determine whether the working first-sense circular transmit/first-sense circular receive radar cross-section, the working first-sense circular transmit/second-sense circular receive radar cross-section, and the working asymmetry angle indicate the working points constitute target points or clutter points.

66. The computer readable medium of claim 65, further comprising instructions for creating a look-up table, the look-up table associating combinations of a first-sense circular transmit/first-sense circular receive radar cross-section, a first-sense circular transmit/second-sense circular receive radar cross-section, and an asymmetry angle as representing target points and clutter points such that the working first-sense circular transmit/first-sense circular receive radar cross-section, the working first-sense circular transmit/second-sense circular receive radar cross-section, and the working asymmetry angle can be looked up in the look-up table to classify the working point as a target point or a clutter point.

67. The computer readable medium of claim 66, further comprising working data for a working area of interest.

68. The computer readable medium of claim 67, wherein the working radar data for the area of interest is collected using ground moving target indicator radar.

69. The computer readable medium of claim 68, wherein the working data comprises range and Doppler working radar data.

70. The computer readable medium of claim 65, wherein the suppressing of the clutter ridge is accomplished with filtering.

71. The computer readable medium of claim 70, wherein the filtering applied to suppress the clutter ridge in the working radar data includes space-time adaptive processing.

72. The computer readable medium of claim 71, wherein the filtering applied to suppress the clutter ridge in the working radar data includes joint domain localized space-time adaptive processing.

73. The computer readable medium of claim 65, wherein the first-sense is a left-sense and the second-sense is a right-sense.

74. The computer readable medium of claim 65, wherein the first-sense is a right-sense and the second-sense is a left-sense.

75. The computer readable medium of claim 65, wherein the working scattering matrix is derived from working vertical single pole data, working horizontal single pole data, and working cross pole data, the working cross pole data including at least one of a working vertical transmit and horizontal receive scan or a working horizontal transmit and vertical receive scan.

76. The computer readable medium of claim 65, wherein the working scattering matrix is derived from working vertical single pole data, working horizontal single pole data, and working cross pole data, the working cross pole data including a working vertical transmit and horizontal receive scan and a working horizontal transmit and vertical receive scan.

77. A computer readable medium having stored thereon instructions for detecting targets in radar signals, the instructions comprising:

instructions for suppressing a clutter ridge appearing in a basis radar data;

instructions calculating for a plurality of basis points in the basis radar data a first-sense circular transmit/first-sense circular receive radar cross-section, a first-sense circular transmit/second-sense circular receive radar cross-section, and an asymmetry angle from a basis scattering matrix;

instructions generating the look-up table of the first-sense circular transmit/first-sense circular receive radar cross-section, the first-sense circular transmit/second-sense circular receive radar cross-section, and the asymmetry angle for the plurality of points in the basis radar data; and

instructions for classifying in the look-up table combinations of the first-sense circular transmit/first-sense circular receive radar cross-section, the first-sense circular transmit/second-sense circular receive radar cross-section, and the asymmetry angle as target points and clutter points.

78. The computer readable medium of claim 77, further comprising collecting basis radar data for a representative area of interest.

79. The computer readable medium of claim 78, wherein the basis radar data for the representative area of interest is collected using ground moving target indicator radar.

80. The computer readable medium of claim 79, wherein the basis radar data comprises range and Doppler basis radar data.

81. The computer readable medium of claim 77, wherein the suppressing of the clutter ridge is accomplished with filtering.

82. The computer readable medium of claim 81 wherein the filtering applied to suppress the clutter ridge in the basis radar data includes space-time adaptive processing.

83. The computer readable medium of claim 82, wherein the filtering applied to suppress the clutter ridge in the basis radar data includes joint domain localized space-time adaptive processing.

84. The computer readable medium of claim 77, wherein the first-sense is a left-sense and the second-sense is a right-sense.

85. The computer readable medium of claim 77, wherein the first-sense is a right-sense and the second-sense is a left-sense.

86. The computer readable medium of claim 77, wherein the basis scattering matrix is derived from basis vertical single pole data, basis horizontal single pole data, and basis cross pole data, the basis cross pole data including at least one of a basis vertical transmit and horizontal receive scan or a basis horizontal transmit and vertical receive scan.

87. The computer readable medium of claim 77, wherein the basis scattering matrix is derived from basis vertical single pole data, basis horizontal single pole data, and basis cross pole data, the basis cross pole data including a basis vertical transmit and horizontal receive scan and a basis horizontal transmit and vertical receive scan.

88. The computer readable medium of claim 77, wherein the identifying of the target points and the clutter points in the look-up table is derived manually by comparing the basis radar data for the representative area of interest with predetermined data.

89. The computer readable medium of claim 77, wherein the identifying of the target points and the clutter points in the look-up table is manually adjusted to classify predetermined clutter points.