Hostile intention assessment system and method

• US 7,548,194 B2
• Filed: 03/14/2006
• Issued: 06/16/2009
• Est. Priority Date: 03/14/2006
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Wood, Thomas E.
• Primary Examiner(s): Gregory; Bernarr E
• Application Number:
  US11/374,830
• Publication Number:
  US 20070216566A1
• Time in Patent Office: 1,190 Days
• Field of Search: 342/27, 342/28, 342 52- 68, 342/175, 342/195, 342 73- 81, 342 89-103, 342/118, 342/146, 342147-158, 342/119, 89/11.1, 89 1816- 1819, 244 31- 33, 701300-302, 701 1- 18, 348143-149, 348/152, 340/540, 340/945, 340/961, 340/963, 340/971, 340/984
• US Class Current: 342/195
• CPC Class Codes: G01S 13/726 Multiple target tracking

Abstract

A hostile intention assessment system and method wherein a tracking sensor subsystem (e.g., radar) tracks targets relative to a critical asset. Determinations are made to assess if a first target is approaching a second target, and to assess if the second target is approaching the critical asset. If the first target is approaching the second target to hide in the radar shadow thereof and the second target is approaching sufficiently close to the critical asset, an alert is generated.

Claims

1. A hostile intention assessment system comprising:

a tracking sensor subsystem for tracking targets relative to a critical asset;

a processing subsystem responsive to the tracking sensor subsystem, programmed to;

determine if a first target is approaching a second target,

determine if the second target is approaching the critical asset, and

if the first target is approaching the second target and the second target is approaching the critical asset, generating a first alert.

2. The system of claim 1 in which determining if the first target is approaching the second target includes computing the closest point of approach and the time to the closest point of approach of the first target relative to the second target.

3. The system of claim 2 in which the processing subsystem is further programmed to generate said first alert when the closest point of approach and the time to the closest point of approach of the first target relative to the second target are below predetermined thresholds.

4. The system of claim 3 in which the processing subsystem is further programmed to time the occurrence of the closest point of approach and the time to the closest point of approach of the first target relative to the second target being below said predetermined thresholds and generating said first alert only if the time duration is greater than a predetermined time duration.

5. The system of claim 1 in which determining if the second target is approaching the critical asset includes computing the closest point of approach and the first alert is only generated if said closest point of approach is below a predetermined threshold.

6. The system of claim 1 in which the processing subsystem is further programmed to determine the size of the first and second targets and the first alert is only generated if the first target is smaller than the second target by a predetermined amount.

7. The system of claim 6 in which the size of the first and second targets is determined by the spatial extent of the targets or the radar cross section of the targets.

8. The system of claim 1 in which the processing subsystem is further programmed to prioritize the tracks of the first and second targets after generating the first alert.

9. The system of claim 1 in which the processing subsystem is further programmed to generate a second alert if the first target becomes untrackable by the sensor subsystem.

10. The system of claim 9 in which the tracking sensor subsystem is configured to provide a track quality indicator for targets.

11. The system of claim 10 in which the processing subsystem generates the second alert if the track quality indicator of the first target is below a predetermined threshold.

12. The system of claim 9 in which the processing subsystem is further programmed to associate the track of the first target with the track of the second target if the first target becomes untrackable by the sensor subsystem.

13. The system of claim 12 in which the processing subsystem is further programmed to generate a third alert if the first target is reacquired by the sensor subsystem.

14. The system of claim 1 in which the tracking sensor subsystem includes a radar subsystem.

15. The system of claim 1 in which the tracking subsystem includes an infrared surveillance and tracking subsystem.

16. The system of claim 1 in which the critical asset is equipped with the tracking sensor subsystem and the processing subsystem.

17. The system of claim 1 in which the critical asset is monitored by an installation equipped with the tracking sensor subsystem and the processing subsystem.

18. A hostile intention assessment system comprising:

a processing subsystem configured to;

compute the closest point of approach and the time to the closest point of approach of a first target relative to a second target,

compute the closest point of approach and the time to the closest point of approach of the second target relative to a critical asset,

determine the size of the first target relative to the second target, and

generate a first alert when the computed closest point of approach of the second target relative to the critical asset is below a predetermined threshold, the size of the first target is small relative to the size of the second target, and the computed closest point of approach and time to the closest point of approach of the first target relative to the second target are below predetermined thresholds for a predetermined duration.

19. The system of claim 18 in which the size of the first and second targets is determined by the spatial extent of the targets or the radar cross section of the targets.

20. The system of claim 18 in which the processing subsystem is further programmed to prioritize the tracks of the first and second targets after generating the first alarm.

21. The system of claim 18 in which the processing subsystem is further programmed to generate a second alert if the first target becomes untrackable by a sensor subsystem.

22. The system of claim 21 in which the processing subsystem is configured to respond to a track quality indicator for all targets.

23. The system of claim 21 in which the processing subsystem generates the second alert if the track quality indicator of the first target is below a predetermined threshold.

24. The system of claim 21 in which the processing subsystem is further programmed to associate the track of the first target with the track of the second target if the first target becomes untrackable by the sensor subsystem.

25. The system of claim 24 in which the processing subsystem is further programmed to generate a third alert if the first target is reacquired by a sensor subsystem.

26. A hostile intention assessment system comprising:

a radar subsystem for tracking targets relative to a critical asset; and

a processing subsystem responsive to the radar subsystem and programmed to;

determine if a smaller craft is approaching a larger vessel,

determine if the larger vessel is approaching the critical asset, and

generate a first alert in response.

27. The system of claim 26 in which the processing subsystem is further programmed to prioritize the tracks of the first and second targets after generating the first alarm.

28. The system of claim 26 in which the processing subsystem is further programmed to generate a second alert if the first target becomes untrackable by the radar subsystem.

29. The system of claim 28 in which the radar subsystem is configured to provide a track quality indicator for all targets.

30. The system of claim 29 in which the processing subsystem generates the second alert if the track quality indicator of the first target is below a predetermined threshold.

31. The system of claim 28 in which the processing subsystem is further programmed to associate the track of the first target with the track of the second target if the first target becomes untrackable by the radar subsystem.

32. The system of claim 31 in which the processing subsystem is further programmed to generate a third alert if the first target is reacquired by the radar subsystem.

33. A hostile intention assessment method comprising:

tracking targets relative to a critical asset;

determining if a first target is approaching a second target;

determining if a second target is approaching the critical asset; and

generating a first alert when the first target is approaching the second target and the second target is approaching the critical asset.

34. The method of claim 33 in which determining if the first target is approaching the second target includes computing the closest point of approach and the time to the closest point of approach of the first target relative to the second target.

35. The method of claim 33 in which determining if the second target is approaching the critical asset includes computing the closest point of approach of the second target relative to the critical asset and the first alert is only generated if said closest point of approach is below a predetermined threshold.

36. The method of claim 33 further including the step of determining the size of the first and second targets and generating the first alert only if the first target is smaller than the second target by a predetermined amount.

37. The method of claim 36 in which the size of the first and second targets is determined by the spatial extent of the targets or the radar cross section of the targets.

38. The method of claim 34 in which the first alert is generated when the closest point of approach and the time to the closest point of approach of the first target relative to the second target are below predetermined thresholds.

39. The method of claim 38 further including the step of determining the duration of the occurrence of the closest point of approach and the time to the closest point of approach of the first target relative to the second target being below said predetermined thresholds and generating said alert only if the duration is greater than a predetermined time duration.

40. The method of claim 33 further including the step of prioritizing the tracks of the first and second targets after generating the first alarm.

41. The method of claim 33 further including the step of generating a second alert if the first target becomes untrackable.

42. The method of claim 41 further including the step of providing a track quality indicator for all targets.

43. The method of claim 42 in which the second alert is generated if the track quality indicator of the first target is below a predetermined threshold.

44. The method of claim 41 further including the step of associating the track of the first target with the track of the second target if the first target becomes untrackable.

45. The method of claim 44 further including the step of generating a third alert if the first target track is reacquired.

46. The method of claim 33 in which tracking includes the use of a radar subsystem.

47. The method of claim 33 in which tracking includes the use of an infrared surveillance and tracking subsystem.

48. A hostile intention assessment method comprising:

tracking targets relative to a critical asset;

determining if a smaller craft is approaching a larger vessel;

determining if the larger vessel is approaching the critical asset; and

generating a first alert in response.

49. The method of claim 48 further including the step of prioritizing the tracks of the first and second targets after generating the first alarm.

50. The method of claim 48 further including the step of generating a second alert if the first target becomes untrackable.

51. The method of claim 50 further including the step of generating a third alert if the track of the first target is reacquired.

52. A hostile intention assessment method comprising:

computing the closest point of approach and the time to the closest point of approach of a first target relative to a second target;

computing the closest point of approach and the time to the closest point of approach of the second target relative to a critical asset;

determining the size of the first target relative to the second target; and

generating a first alert when the computed closest point of approach of the second target relative to the critical asset is below a predetermined threshold, the size of the first target is small relative to the size of the second target by a selected amount, and the computed closest point of approach and time to the closest point of approach of the first target relative to the second target are below predetermined thresholds for a predetermined duration.

53. A hostile intention assessment system comprising:

a radar subsystem for tracking targets relative to a critical asset; and

a processing subsystem responsive to the radar subsystem and programmed to;

determine if a smaller craft is approaching a larger vessel,

determine if the larger vessel is approaching the critical asset, and

associate the track of the smaller craft with the track of the larger vessel when the smaller craft is hidden in the radar shadow of the larger vessel.

54. A hostile intention assessment system comprising:

a processing subsystem configured to;

compute the approach a first target relative to a second target,

compute the approach of the second target relative to a critical asset,

determine the size of the first target relative to the second target,

determine relationship of both the first and second targets relative to the critical asset, and

generate an alert when the computed approach of the second target relative to the critical asset meets a predetermined threshold, the size of the first target is small relative to the size of the second target, the computed approach of the first target relative to the second target meets a predetermined threshold for a predetermined duration, and the smaller target is further from the critical asset than the larger target.