Detection and removal of self-alerts in a tracking system

• US 6,594,578 B2
• Filed: 06/27/2001
• Issued: 07/15/2003
• Est. Priority Date: 07/10/2000
• Status: Active Grant

• Current Assignee: Garmin AT, Inc. (Garmin Limited)
• Original Assignee: United Parcel Service of America (United Parcel Service Incorporated)
• Inventors: Lai, Chih
• Primary Examiner(s): NGUYEN, THU V
• Application Number:
  US09/892,597
• Publication Number:
  US 20020004698A1
• Time in Patent Office: 748 Days
• Field of Search: 701/1, 701/3-4, 701/9, 701/14-16, 701/23-27, 701/120-122, 342/29, 342/36-37, 342/40, 342/63, 342/65, 342/89, 342/93, 342/95, 342/113-114, 342/90
• US Class Current: 701/120
• CPC Class Codes: G01S 13/765 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 13/784 Coders or decoders therefor; Degarbling systems; Defruiting systems
• CPC Class Codes: G01S 13/91 for traffic control G01S13/93 takes precedence

Abstract

Improved methods and systems for detecting self-alerts from upload messages in a TIS system to thereby eliminate the likelihood of TIS self-alerts appearing on CDTI displays. The present invention determines whether a self-alert was present in a previous traffic information uplink to determine whether a target in a current information uplink is real. Using a weighting algorithm, typically a fuzzy logic algorithm, a system in accordance with the present invention can distinguish between targets in consecutive radar sweeps to identify self-alerts. If the self-alert was not present in previous uplinks, then the system removes the self-alert from subsequent views on the CDTI. Thus, the present invention provides an improved visual display system for pilots and air traffic controllers.

Claims

1. A method for detecting self-alerts in upload messages in a TIS system, the method comprising:

receiving, at ownship, first and second TIS upload messages, each message comprising TIS information for targets proximate the ownship; and

identifying a target in the first TIS message as a self-alert if the target is within pre-defined self-alert conditions of ownship and the target is not associated with any target in the second TIS message.

2. The method of claim 1 wherein the TIS information includes report parameters, and wherein identifying a target further comprises determining a weighted sum of differences in corresponding report parameters between a target in the first TIS message and each target in the second TIS message and determining if the target in the first TIS message is associated with any of the targets of the second TIS message based upon the weighted sum of differences as compared to a threshold.

3. The method of claim 1, wherein the TIS information includes bearing, range, track, relative altitude and altitude rate parameters, and wherein identifying a target further comprises determining a weighted sum of differences in corresponding bearing, range, track, relative altitude and altitude rate parameters between a target in the first TIS message and each target in the second TIS message and determining if the target in the first TIS message can be associated with any of the targets of the second TIS message based upon the weighted sum of differences as compared to a threshold.

4. The method of claim 3, wherein determining a weighted sum of differences in corresponding bearing, range, track, relative altitude and altitude rate parameters further comprises weighting the range and track parameters to a different degree than the relative altitude and altitude rate parameters, thereby emphasizing the range and track parameters over the relative altitude and altitude rate parameters.

5. A method for detecting self alerts in upload messages in a TIS system, the method comprising:

receiving, at ownship, first and second TIS upload messages, each message comprising TIS information for targets proximate the ownship;

collecting pre-defined TIS information for each target in the first and second TIS upload messages for the purpose of detecting self-alerts;

determining differences as compared between the pre-defined TIS information for each target in the first TIS upload message to each target in the second TIS upload messages;

applying pre-defined weights to the differences of each comparison;

summing the weighted differences of each comparison; and

filtering a target if the summed weighted differences exceeds a predefined threshold.

6. The method of claim 5, wherein collecting pre-defined TIS information for each target in the first and second TIS upload messages further comprises collecting from each target in the first and second TIS upload messages at least one TIS field from the group consisting of traffic bearing, range, relative altitude, altitude rate, and track.

7. The method of claim 5, wherein collecting pre-defined TIS information for each target in the first and second TIS upload messages further comprises collecting TIS information related to at least traffic bearing, range, relative altitude, altitude rate, and track from the first and second TIS upload message.

8. The method of claim 7, wherein applying pre-defined weights to the differences further comprises applying a weight to range and track TIS information that is different from that applied to relative altitude and altitude rate TIS information.

9. The method of claim 5, wherein applying pre-defined weights to the differences further comprises applying a pre-determined weight based on empirical data to the differences between the pre-defined TIS information for each target in the first and second TIS upload messages.

10. The method of claim 5, wherein filtering a target further comprises comparing the summed weighted differences to a pre-defined maximum threshold level based on empirical data to assess whether each of the targets of the first and second TIS upload messages are associated.

11. The method of claim 5, wherein filtering a target in the second TIS upload message if the comparison results in the summed weighted differences exceeding the predefined threshold further comprises filtering a target by comparing the range for the target in the second TIS upload message to a maximum limit for range.

12. The method of claim 5, wherein filtering a target in the second TIS upload message if the comparison results in the summed weighted differences exceeding the predefined threshold further comprises filtering by comparing the relative altitude for the target in the second TIS upload message to a maximum limit for relative altitude.

13. The method of claim 5, wherein filtering a target the second TIS upload message if the comparison results in the summed weighted differences exceeding the predefined threshold further comprises filtering by comparing the range and relative altitude for the target in the second TIS message to maximum limits for range and relative altitude.

14. The method of claim 13 wherein the TIS information includes report parameters, and wherein identifying a target further comprises determining a weighted sum of differences in corresponding report parameters between a target in the first TIS message and each target in the second TIS message and determining if the target in the first TIS message is associated with any of the targets of the second TIS message based upon the weighted sum of differences as compared to a threshold.

15. A method for detecting and removing self-alerts in a TIS system, the method comprising:

receiving, at ownship, a first and second TIS upload message, each message comprising TIS information for targets proximate the ownship;

identifying a target in the first TIS message as a self-alert if the target is within pre-defined self-alert conditions of ownship and the target is not associated with any target in the second TIS message; and

removing the target in the first TIS message from a subsequent view of a CDTI display.

16. The method of claim 15, wherein the TIS information includes bearing, range, track, relative altitude and altitude rate parameters, and wherein identifying a target further comprises determining a weighted sum of differences in corresponding range, track, relative altitude and altitude rate parameters between a target in the first TIS message and each target in the second TIS message and determining if the target in the first TIS message is associated with any of the targets of the second TIS message based upon the weighted sum of differences as compared to a threshold.

17. The method of claim 16, wherein determining a weighted sum of differences in corresponding bearing, range, track, relative altitude and altitude rate parameters further comprises weighting the range and track parameters to a different degree than the relative altitude and altitude rate parameters, thereby emphasizing the range and track parameters over the relative altitude and altitude rate parameters.

18. A computer program product for detecting self alerts in upload messages in a TIS system, comprising:

a computer usable medium having computer readable program code means embodied in the medium for causing detection of self alerts in upload messages in a TIS system, the computer readable program code including;

computer readable program code for causing said computer to receive a first and second TIS upload message, each message comprising TIS information for targets proximate an ownship; and

computer readable program code for causing said computer to identify a target in the first TIS message as a self-alert if the target is within pre-defined self-alert conditions of ownship and the target is not associated with any target in the second TIS message.

19. The computer program product of claim 18, wherein the TIS information includes report parameters, and wherein the computer readable program code for causing said computer to identify a target further comprises computer readable program code for causing said computer to determine a weighted sum of differences in corresponding report parameters between a target in the first TIS message and each target in the second TIS message and computer readable program code for causing said computer to determine if the target in the first TIS message is associated with any of the targets of the second TIS message based upon the weighted sum of differences as compared to a threshold.

20. The computer program product of claim 19, wherein the TIS information includes bearing, traffic range, traffic track, relative altitude and altitude rate parameters, and wherein the computer readable program code for causing said computer to identify a target further comprises computer readable program code for causing said computer to determine a weighted sum of differences in corresponding bearing, range, track, relative altitude and altitude rate parameters between a target in the first TIS message and each target in the second TIS message and computer readable program code for causing said computer to determine if the target in the first TIS message is associated with any of the targets of the second TIS message based upon the weighted sum of differences as compared to a threshold.

21. The computer program product of claim 20, wherein the computer readable program code for causing said computer to determine a weighted sum of differences in corresponding bearing, range, track, relative altitude and altitude rate parameters further comprises computer readable program code for causing said computer to weigh the range and track parameters to a greater degree than the relative altitude and altitude rate parameters.

22. A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform a method for detecting self alerts in upload messages in a TIS system, the method comprising:

receiving first and second TIS upload messages, each message comprising TIS information for targets proximate an ownship;

collecting pre-defined TIS information for each target in the first and second TIS upload messages for the purpose of detecting self-alerts;

determining differences between the pre-defined TIS information for each target in the first and second TIS upload messages;

applying a pre-defined weight to the differences between the pre-defined TIS information for each target in the first and second TIS upload messages;

summing the weighted differences of the pre-defined TIS information for each target in the first and second TIS upload messages;

comparing the summed weighted differences to a pre-defined maximum threshold level to assess whether each of the targets in the first and second TIS upload messages are associated; and

filtering a target in the second TIS upload message if the comparison results in the summed weighted differences exceeding the predefined threshold.

23. The program storage device of claim 22, wherein collecting pre-defined TIS information for each target in the first and second TIS upload messages further comprises collecting from each target in the first and second TIS upload messages at least one TIS field from the group consisting of bearing, range, relative altitude, altitude rate, and traffic track.

24. The program storage device of claim 22, wherein collecting pre-defined TIS information for each target in the first and second TIS upload messages further comprises collecting TIS information related to traffic bearing, range, relative altitude, altitude rate, and track from the first and second TIS upload message.

25. The program storage device of claim 22, wherein applying a pre-defined weight to the differences between the pre-defined TIS information for each target in the first and second TIS upload messages further comprises applying a pre-determined weight based on empirical flight-test data to the differences between the pre-defined TIS information for each target in the first and second TIS upload messages.

26. The program storage device of claim 22, wherein applying a pre-defined weight to the differences between the pre-defined TIS information for each target in the first and second TIS upload messages further comprises applying greater weight to range and track TIS information and less weight to relative altitude and altitude rate TIS information.

27. The program storage device of claim 22, wherein comparing the summed weighted differences to a pre-defined maximum threshold level to assess whether each of the targets of the first and second TIS upload messages are associated further comprises comparing the summed weighted differences to a pre-defined maximum threshold level based on empirical flight-test data to assess whether each of the targets of the first and second TIS upload messages are associated.

28. The program storage device of claim 22 wherein filtering a target in the second TIS upload message if the comparison results in the summed weighted differences exceeding the predefined threshold further comprises filtering a target by comparing the range for the target in the second TIS upload message to a maximum limit for range.

29. The program storage device of claim 22, wherein filtering the second TIS upload message if the comparison results in the summed weighted differences exceeding the predefined threshold further comprises filtering by comparing the relative altitude for the target in the second TIS upload message to a maximum limit for relative altitude.

30. The program storage device of claim 22, wherein filtering the second TIS upload message if the comparison results in the summed weighted differences exceeding the predefined threshold further comprises filtering by comparing the range and relative altitude for the target in the second TIS message to maximum limits for range and relative altitude.