Method and apparatus for search and tracking

• US 5,001,650 A
• Filed: 04/10/1989
• Issued: 03/19/1991
• Est. Priority Date: 04/10/1989
• Status: Expired due to Fees

• Current Assignee: Hughes Aircraft Company Los Angeles CA
• Original Assignee: Hughes Aircraft Company (Rtx Corporation)
• Inventors: Gray, Paul T., Francis, W. Leon, Margerum, Walter G.
• Primary Examiner(s): Lall, Parshotam S.
• Assistant Examiner(s): Ramirez, Ellis B.
• Application Number:
  US07/335,659
• Time in Patent Office: 708 Days
• Field of Search: 364/516, 364/517, 364/449, 364/525, 364/423, 364/572, 356/5, 356/152, 358/107, 358/113, 250/332, 250/333, 244/3.16, 382/28
• US Class Current: 348/169
• CPC Class Codes: G01S 3/7864 T.V. type tracking systems

Abstract

A method and apparatus for search and tracking multiple targets in an object space. The apparatus (10) includes a targeting FLIR unit (12) operating in imaging mode. The targeting FLIR unit (12) is operable to generate an output in response to the observations of the multiple targets. The apparatus (10) also includes an infrared search and tracking electronics unit (48) for allowing the apparatus (10) to detect and track the multiple targets in response to the output of the targeting FLIR unit (12).

Claims

1. An apparatus for each search and simultaneously tracking multiple moving and nonmoving targets in an object space comprising:

a targeting FLIR unit operating in imaging mode, said targeting FLIR unit generating an electrical output in response to observations of said multiple moving and nonmoving targets; and

means for detecting and tracking said multiple moving and nonmoving targets in response to said electrical output of said targeting FLIR unit.

2. The apparatus of claim 1, wherein said means for detecting and tracking said multiple targets comprises a signal processor and a data processor.

3. The apparatus of claim 2, wherein each of said targets forms at least one observation, and wherein said signal processor comprises:

means for generating an adaptive threshold; and

means for limiting the number of observations processed by said data processor.

4. The apparatus of claim 3, wherein said signal processor comprises means for compensating for multiple exceedances of said adaptive threshold from the same target.

5. The apparatus of claim 2, wherein said data processor comprises:

means for generating tracks from the output of said signal processor; and

means for classifying said tracks into target tracks, tentative tracks, and clutter tracks.

6. The apparatus of claim 5, wherein said data processor further comprises means for assigning new observations to existing tracks.

7. The apparatus of claim 2, wherein said data processor further comprises means for eliminating ghosts generated by said targeting FLIR unit.

8. The apparatus of claim 2, wherein said data processor comprises means for deleting observations of said targets which are generated by overscan of said targets by said targeting FLIR unit.

9. An apparatus for allowing an operator to continuously search and track a plurality of targets moving in an object space comprising:

a targeting FLIR unit operating in imaging mode, said targeting FLIR unit operable to generate a first output in response to observations of said plurality of targets;

a system electronics unit for controlling the operation of said targeting FLIR unit;

a monitor for displaying a portion of said object space to said operator, said monitor electrically communicating with said system electronics unit;

a signal processor electrically communicating with said system electronics unit; and

a data processor electrically communicating with said signal processor and said systems electronics unit, said data processor comprising;

means for forming tracks from the first output of said targeting FLIR unit,

means for assigning said observations to established tracks operable to generate a second output,

means for filtering the output of said means for assigning observations to established tracks,

means for classifying said tracks into target tracks, tentative tracks, and clutter tracks,

means for eliminating ghosts generated by said targeting FLIR unit, and

means for deleting observations of said targets which are generated by overscan of said targets by said targeting FLIR unit.

10. The apparatus of claim 9, wherein said signal processor comprises:

means for generating an adaptive threshold operable to reduce the possibility that said apparatus will identify natural backgrounds as targets; and

means for generating a clutter map threshold operable to limit the number of observations which are processed by said data processor.

11. The apparatus of claim 10, wherein means for generating an adaptive threshold comprise:

a target filter operable to generate a third output;

a guard filter operable to generate a fourth output; and

means for determining whether said third output of said target filter exceeds both said clutter map threshold as well as said fourth output of said guard filter.

12. The apparatus of claim 11, wherein said means for generating a clutter map threshold is operable to:

calculate the number of observations which exceed a predetermined threshold;

determine whether the number of observations which exceed said predetermined threshold is within a desired band;

raise said threshold if the number of observations which exceed said predetermined threshold is greater than the upper limit of said desired band; and

lower said predetermined threshold if the number of observations which exceed said predetermined threshold is less than the lower limit of said desired band.

13. The apparatus of claim 12, wherein said signal processor further comprises means for compensating for multiple exceedances of said adapative threshold from the same target.

14. The apparatus of claim 9, wherein said means for forming tracks comprises a track acquisition algorithm.

15. The apparatus of claim 14, wherein said means for assigning observations to established tracks comprises a track association algorithm.

16. The apparatus of claim 15, wherein said means for filtering comprises a track filter algorithm.

17. The apparatus of claim 16, wherein said means for classifying said tracks comprises a track classification algorithm.

18. The apparatus of claim 17, wherein said means for eliminating ghosts comprises a vidicon ghost logic algorithm.

19. The apparatus of claim 18, wherein said means for deleting observations comprises a FLIR overscan logic algorithm.

20. A method for searching and simultaneously tracking a plurality of moving and nonmoving targets in an object space comprising:

sensing said targets using a targeting FLIR unit operating in an imaging mode, said targeting FLIR unit operable to operable an electrical output; and

processing said electrical output from said targeting FLIR unit to allow search and simultaneously tracking of said plurality of moving and nonmoving targets.

21. The method of claim 20, wherein said step of processing the output from said targeting FLIR unit further comprises the step of executing an adaptive threshold algorithm.

22. The method of claim 21, wherein said step of processing the output of said targeting FLIR unit further comprises the step of executing a clutter map threshold algorithm.

23. The method of claim 22, wherein said step of processing the output of said targeting FLIR unit further comprises the step of executing a peak detection algorithm.

24. The method of claim 23, wherein said step of processing the output of said targeting FLIR futher comprises the step of executing a track association algorithm.

25. The method of claim 24, wherein said step of processing the output of said targeting FLIR unit further comprises the step of executing a track classification algorithm.

26. The method of claim 25, wherein said step of processing the output of said targeting FLIR unit further comprises the step of executing a track acquisition algorithm.

27. The method of claim 26, wherein said step of processing the output of said targeting FLIR unit further comprises the step of executing an observation acceptance function.

28. The method of claim 27, wherein said step of processing the output of said targeting FLIR unit comprises the step of executing a vidicon ghost logic algorithm.

29. The method of claim 28, wherein said step of processing the output of said targeting FLIR unit further comprises the step of executing a FLIR overscan logic algorithm.

30. The method of claim 20, wherein said step of sensing said targets using a targeting FLIR unit comprises the step of panning said targeting FLIR unit.