Method and apparatus for identifying ownship threats

• US 7,148,835 B1
• Filed: 06/24/2005
• Issued: 12/12/2006
• Est. Priority Date: 06/24/2005
• Status: Expired due to Fees

• Current Assignee: Lawrence Livermore National Security LLC (Government of the United States of America), Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Wanchissen, Stephen P., Gounalis, Anthony J., Rosswog, James C., Bricker, Jeffrey K.
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US11/166,405
• Publication Number:
  US 20060290560A1
• Time in Patent Office: 536 Days
• Field of Search: 342 13- 20, 342 74- 81, 342/89, 342/90, 342/165, 342/173, 342/175, 342192-197, 342450-465
• US Class Current: 342/20
• CPC Class Codes: F41H 11/02 Anti-aircraft or anti-guided missile or anti-torpedo defence installations or systems cartridges or missiles for producing smoke or for dispensing radar chaff or infrared material F42B5/15, F42B12/48, F42B12/70; informative reference: details of radar or sonar systems G01S7/00; jamming or electronic countermeasures G01S7/38, G01S7/495, H04K3/00
• CPC Class Codes: G01S 7/021 Auxiliary means for detecting or identifying radar signals or the like, e.g. radar jamming signals

Abstract

A method and apparatus for evaluating whether one or more threat sources is actively tracking an object, such as an aircraft. A tracking system may analyze information regarding signals received from a source and provide a track indication that the source is actively tracking the object without adjusting the dwell arrangement of the scan strategy of the receiver. A track indication may be provided where a sample count of signal intercepts from the source is greater than a track count during a window. A break track indication representing that the source is not actively tracking the object may be provided when a number of signal intercepts from the source is less than a break track count during a window.

Claims

1. A threat evaluation system comprising:

a receiver associated with an object, the receiver adapted to implement a scan strategy including a dwell arrangement to receive signals emitted by one or more threat emitters, the signals being emitted by the one or more threat emitters to locate the object or similar items; and

a tracking system that receives information from the receiver regarding received signals, the tracking system analyzing signals from a threat emitter to provide a track indication that the threat emitter is actively tracking the object without adjusting the dwell arrangement of the scan strategy of the receiver.

2. The system of claim 1, wherein the receiver provides intercept reports regarding signals received from identified threat emitters.

3. The system of claim 1, wherein the tracking system receives information from the receiver regarding amplitude and time of arrival of signals received from the threat emitter.

4. The system of claim 3, wherein the tracking system provides the track indication when an intercept rate of signals received from the threat emitter exceeds a track rate for the threat emitter.

5. The system of claim 4, wherein the tracking system provides the track indication when the intercept rate of signals received from the threat emitter exceeds a track rate for the threat emitter, and where each of the signals received from the threat emitter has an amplitude that exceeds a threshold.

6. The system of claim 1, wherein the tracking system is adapted to provide track indications for a plurality of threat emitters without adjusting the dwell arrangement of the scan strategy of the receiver.

7. The system of claim 1, wherein the receiver provides an indication of one or more signals received from the threat emitter;

and

wherein the tracking system analyzes the one or more signals from the threat emitter and provides a track indication that the threat emitter is actively tracking the object when a sample count of signals received from the threat emitter is greater than a track count during a window, and provides a break track indication that the threat emitter is not actively tracking the object when a number of signals from the threat emitter is less than a break track count during a window.

8. The system of claim 7, wherein the track indication is provided when the sample count of signals is greater than the track count during the window, and where each of the signals has a signal amplitude exceeding a threshold.

9. The system of claim 1, wherein the object is an airplane, a helicopter, vessel or other suitable vehicle or platform.

10. A threat evaluation system comprising:

a receiver associated with an object, the receiver adapted to receive signals emitted by one or more threat emitters, and providing an indication of at least one signal intercept from a threat emitter based on one or more signals received from the threat emitters, the signals being emitted by the one or more threat emitters to locate the object or similar items; and

a tracking system that receives information from the receiver regarding signal intercepts, the tracking system analyzing at least one signal intercept from the threat emitter and providing a track indication that the threat emitter is actively tracking the object when a sample count of signal intercepts from the threat emitter is greater than a track count during a window, and providing a break track indication that the threat emitter is not actively tracking the object.

11. The system of claim 10, wherein the track indication is provided when the sample count of signal intercepts, each having a signal amplitude exceeding a low threshold, is greater than the track count during the window.

12. The system of claim 11, wherein the tracking system only includes signal intercepts in the sample count for a window if the receiver detects a signal amplitude for a signal intercept that is greater than a high threshold, where the high threshold is greater than the low threshold.

13. The system of claim 12, wherein after a break track indication is provided, the tracking system does not provide a track indication until the receiver detects a signal amplitude for a signal intercept that is greater than a high threshold, where the high threshold is greater than the low threshold.

14. The system of claim 13, wherein the tracking system adjusts the high threshold based on a peak signal amplitude in the window.

15. The system of claim 10, wherein the break track indication is provided when a number of signal intercepts from the threat emitter is less than a break track count during a window.

16. The system of claim 10, wherein the tracking system is adapted to provide tracking indications and break track indications for a plurality of threat emitters.

17. The system of claim 10, wherein the receiver includes a library identification system adapted to determine from at least one signal intercept a threat emitter type, an association of the at least one signal intercept with a previously identified threat emitter, and/or whether the threat emitter is in a track or scan mode.

18. The system of claim 10, wherein the tracking system is adapted to use customized information for each of a plurality of threat emitters when analyzing at least one signal intercept from the threat emitter, the customized information including information regarding an expected signal amplitude of the threat emitter when in tracking mode, an expected rate of signal intercept for the threat emitter when in tracking mode, a low threshold for the threat emitter, a track count for the threat emitter, a break track count for the threat emitter, a high threshold for the threat emitter, and/or a window size for the threat emitter.

19. The system of claim 10, wherein if the tracking system previously provided a track indication for a prior window, the tracking system does not subsequently provide a break track indication for a next window if a peak amplitude for signal intercepts in the next window is larger than a peak amplitude for signal intercepts in the prior window.

20. A method of identifying one or more threats to an object, comprising:

implementing a scan strategy for a receiver, the scan strategy including a dwell arrangement defining one or more time periods during which the receiver is intended to receive signals from one or more directions;

receiving, at the receiver, signals emitted by one or more threat emitters, the signals being emitted by the one or more threat emitters to locate an object associated with the receiver; and

providing, based on the received signals, a track indication that at least one threat emitter is actively tracking the object without adjusting the dwell arrangement of the scan strategy for the receiver.