Target detection method

• US 5,731,539 A
• Filed: 10/02/1992
• Issued: 03/24/1998
• Est. Priority Date: 10/02/1992
• Status: Expired due to Fees

• Current Assignee: General Dynamics C4 Systems Incorporated (General Dynamics Corporation)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Hill, Douglas Wade, Casey, Timothy Edmund, Hayden, Rhett Garrett
• Primary Examiner(s): Lobo, Ian J.
• Application Number:
  US07/955,584
• Time in Patent Office: 1,999 Days
• Field of Search: 102/211, 244/3.15, 244/3.16, 382/1, 382/48
• US Class Current: 102/211
• CPC Class Codes: F42C 13/04 operated by radio waves
• CPC Class Codes: G01S 13/89 for mapping or imaging

Abstract

A target detection method collects spatial data relating to a target at an instant in time. This data is converted to an appropriate coordinate system, such as Cartesian coordinates. A centroid of the target is determined. Predictions of the centroid are made at subsequent time intervals. The predicted centroids are averaged with the current determined centroids. When the closest centroid position of the target is determined, an indication is provided for detonating the warhead of a projectile.

Claims

1. In a fuzing arrangement of a missile, a target detection method comprising the steps of:

receiving ranging, elevation, and azimuth information relating to a detected target at a first time;

converting the ranging, elevation, and azimuth information to a plurality of orthogonal planes of Cartesian coordinates;

incrementing the first time to a succeeding time;

iterating the steps of receiving, converting, and incrementing for a plurality of succeeding times;

predicting Cartesian coordinates of a centroid of the target based upon the planes of Cartesian coordinates of the target;

combining the Cartesian coordinates of the predicted centroid with the Cartesian coordinates of a currently measured centroid of the target; and

providing an indication to the fuzing arrangement that the centroid of the target is in proximity to the missile.

2. A target detection method as claimed in claim 1, wherein the step of predicting includes the step of combining the Cartesian coordinates for each of the plurality of planes.

3. A target detection method as claimed in claim 1, wherein the step of receiving includes the step of receiving the ranging, elevation, and azimuth information relating to the target from a plurality of detection beams of the missile.

4. A target detection method as claimed in claim 3, wherein there is further included the step of iterating the steps of receiving, converting, incrementing, and iterating until a detonation of a warhead of the missile occurs.

5. A target detection method as claimed in claim 4, wherein there is further included the steps of:

determining whether the target has been detected; and

iterating the step of incrementing for each of the detection beams, if the target has not been detected.

6. A target detection method as claimed in claim 5, wherein there is further included the steps of:

determining which of the plurality of detection beams has the greatest number of detections of the target, if the target has been detected; and

computing the minimum tracking time from the missile to one of said plurality of detection beams with the greatest number of target detections.

7. A target detection method as claimed in claim 6, wherein there is further included the steps of:

determining a detonation time of a warhead of the missile; and

determining the aim position coordinates of the target.

8. A target detection method as claimed in claim 7, wherein there is further included the step of indicating that the warhead is to be detonated.

9. A target detection method as claimed in claim 8, wherein there is further included the step of detonating the warhead of said missile.

10. A target detection method as claimed in claim 8, wherein there is further included the steps of:

incrementing the succeeding time to a new time; and

iterating said steps of receiving, converting, incrementing, and iterating, if the warhead has not been detonated.

11. A target detection method as claimed in claim 1, wherein the step of combining the Cartesian coordinates of the predicted centroid with the Cartesian coordinates of the currently measured centroid of the target includes the step of averaging the Cartesian coordinates of the predicted centroid with the Cartesian coordinates of the currently measured centroid of the target for each of said plurality of orthogonal planes.

12. In a fuze of a projectile, a target detection method comprising the steps of:

repeatedly receiving ranging, elevation, and azimuth information relating to a detected target;

converting the ranging, elevation, and azimuth information to a plurality of orthogonal planes of Cartesian coordinates;

determining, at intervals, Cartesian coordinates for a current position of the centroid of the target;

predicting Cartesian coordinates of the centroid of the target based upon the Cartesian coordinates of the current position of the target, for a next succeeding time interval;

averaging the Cartesian coordinates of the predicted centroid with the Cartesian coordinates of the current position of the centroid of the target to produce a best approximation of the centroid of the target; and

indicating when the best approximation of the centroid of the target is spatially near to the projectile.

13. A target detection method as claimed in claim 12, wherein the step of receiving includes the step of receiving the ranging, elevation, and azimuth information relating to the target from a plurality of detection beams of the projectile.

14. A target detection method as claimed in claim 13, wherein there is further included the steps of:

determining whether the target has been detected; and

iterating the steps of receiving, converting, incrementing, iterating, iterating and determining for each of the detection beams, if the target has not been detected.

15. A target detection method as claimed in claim 14, wherein there is further included the steps of:

determining which of the plurality of detection beams has the greatest number of detections of the target, if the target has been detected; and

computing the minimum tracking time from the missile to one of said plurality of detection beams with the greatest number of target detections.

16. A target detection method as claimed in claim 15, wherein there is further included the steps of:

determining a detonation time of a warhead of the projectile; and

determining the aim position coordinates of the target.

17. A target detection method as claimed in claim 16, wherein there is further included the step of indicating that the warhead is to be detonated.

18. A target detection method as claimed in claim 17, wherein there is further included the step of detonating the warhead of said projectile.

19. A target detection method as claimed in claim 17, wherein there is further included the steps of:

incrementing the next succeeding time to a new time; and

iterating said steps of receiving, converting and incrementing, if the warhead has not been detonated.

20. A target detection method as claimed in claim 17, wherein there is further included the step of computing an aim direction for a directional pattern warhead.

21. In a fuze of a projectile, a target detection method comprising the steps of:

repeatedly receiving ranging, elevation, and azimuth information relating to a detected target;

converting the ranging, elevation, and azimuth information to a plurality of orthogonal planes of Cartesian coordinates;

determining, at intervals, Cartesian coordinates for a current position of the centroid of the target;

predicting Cartesian coordinates of the centroid of the target based upon the Cartesian coordinates of the current position of the target, for a next succeeding time interval;

averaging the Cartesian coordinates of the predicted centroid with the Cartesian coordinates of the current position of the centroid of the target to produce a best approximation of the centroid of the target; and

indicating when the best approximation of the centroid of the target is spatially near to the projectile;

determining detonation time of a warhead relative to the target;

determining the aim Cartesian coordinates of the target;

determining whether the warhead detonation will produce a lethal effect upon the target; and

detonating the warhead, if the warhead detonation will produce a lethal effect upon the target.