PRECISION REGISTRATION FOR RADAR

• US 20090167591A1
• Filed: 11/24/2008
• Published: 07/02/2009
• Est. Priority Date: 11/30/2007
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Abbett, Michael R., Torres, Sergio
• Granted Patent: US 8,054,215 B2
• Time in Patent Office: Days
• US Class Current: 342/37
• CPC Class Codes: G01S 13/765 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 13/91 for traffic control G01S13/93 takes precedence
• CPC Class Codes: G01S 5/0027 of actual mobile position, i.e. position determined on mobile
• CPC Class Codes: G01S 7/4004 of parts of a radar system

Abstract

A precision radar registration (PR²) system and method that employs highly accurate geo-referenced positional data as a basis for correcting registration bias present in radar data. In one embodiment, the PR² method includes sample collection and bias computation function processes. The sample collection process includes ADS-B sample collection, radar sample collection, and time alignment sub-processes. The bias computation function process includes bias computation, quality monitoring and non-linear effects monitoring sub-processes. The bias computation sub-process results in a bias correction solution including range bias b_ρ, azimuth bias b_θ, and time bias b_T parameters. The quality monitoring sub-process results in an estimate of solution quality. The non-linear effects monitoring sub-process results in detection of the presence of non-linear bias, if any, in the bias correction solution.

Claims

1. A radar registration system comprising:

a radar operable to output radar data including a plurality of radar-based position reports associated with one or more targets moving within a range of the radar;

a geo-referenced position source operable to output a plurality of geo-referenced position reports associated with the one or more targets; and

a processor operable to compute position and time bias parameters associated with the radar by analyzing the radar-based position reports using the geo-referenced position reports as a reference.

2. The system of claim 1 wherein the processor executes a linear regression analysis to analyze the radar-based position reports using the geo-referenced position reports as a reference.

3. The system of claim 2 wherein the linear regression analysis is executed in a manner providing a single pass closed solution for the position and time bias parameters.

4. The system of claim 1 wherein the position bias parameters comprise a range bias and an azimuth bias that are orthogonal to one another and to the time bias.

5. The system of claim 1 wherein the processor is included within an air traffic control system.

6. The system of claim 1 wherein the processor operates in parallel with a legacy radar registration function.

7. The system of claim 1 wherein said processor is further operable to time align the plurality of radar-based position reports with the plurality of geo-referenced position reports without source dependency.

8. The system of claim 1 wherein said processor is further operable to perform quality monitoring during computation of the position and time bias parameters to provide an estimate of the quality of the position and time bias parameters.

9. The system of claim 1 wherein said processor is further operable to monitor non-linear effects present in the computation of the position and time bias parameters to detect a non-linear bias.

10. The system of claim 1 wherein the radar comprises a first radar, wherein the plurality of radar-based position reports comprise a first plurality radar-based position reports associated with one or more targets moving within a range of the first radar, and wherein said system further comprises:

a second radar operable to output radar data including a second plurality of radar-based position reports associated with one or more targets moving within a range of said second radar, wherein the ranges of said first and second radars overlap;

said processor being further operable to compute position and time bias parameters associated with the second radar by analyzing the second plurality of radar-based position reports using the first plurality of radar-based position reports as a reference after registration of the first plurality of radar-based position reports in accordance with the position and time bias parameters associated with the first radar.

11. The system of claim 10 wherein the processor executes a linear regression analysis to analyze the second plurality of radar-based position reports using the registered first plurality of radar-based position reports as a reference.

12. A method of registering a radar, said method comprising:

collecting a plurality of radar data samples from the radar, the radar data samples comprising radar-based position reports associated with one or more targets moving within range of the radar;

collecting a plurality of geo-referenced data samples from a geo-referenced position source, the geo-referenced data samples comprising geo-referenced position reports associated with the one or more targets; and

computing position and time bias parameters associated with the radar by analyzing the radar-based position reports using the geo-referenced position reports as a reference.

13. The method of claim 12 wherein said step of computing position and time bias parameters comprises:

executing a linear regression analysis to analyze the radar-based position reports using the geo-referenced position reports as a reference.

14. The method of claim 13 wherein the linear regression analysis is executed in a manner providing a single pass closed solution for the position and time bias parameters.

15. The method of claim 12 wherein in said step of computing position and time bias parameters, the position bias parameters comprise a range bias and an azimuth bias that are orthogonal to one another and to the time bias.

16. The method of claim 12 wherein said step of computing position and time bias parameters, computation of the position and time bias parameters occurs on a processor within an air traffic control system.

17. The method of claim 12 wherein said computing step is undertaken in parallel with a legacy radar registration function.

18. The method of claim 12 further comprising the step of:

time aligning the radar data samples with the geo-referenced data samples without source dependency.

19. The method of claim 12 further comprising the step of:

performing a quality monitoring during computation of the position and time bias parameters to provide an estimate of the quality of the position and time bias parameters.

20. The method of claim 12 further comprising the step of:

monitoring non-linear effects present in the computation of the position and time bias parameters to detect a non-linear bias.

21. The method of claim 12 wherein the radar comprises a first radar, wherein the radar data samples collected from the first radar comprise a first plurality of radar-based position reports associated with one or more targets moving within a range of the first radar, and wherein said method further comprises:

collecting a plurality of radar data samples from a second radar, the radar data samples collected from the second radar comprising a second plurality of radar-based position reports associated with one or more targets moving within a range of the second radar, wherein the ranges of the first and second radars overlap; and

computing position and time bias parameters associated with the second radar by analyzing the second plurality of radar-based position reports using the first plurality of radar-based position reports as a reference after registration of the first plurality of radar-based position reports in accordance with the position and time bias parameters associated with the first radar.

22. The method of claim 21 wherein said step of computing position and time bias parameters associated with the second radar comprises:

executing a linear regression analysis to analyze the second plurality of radar-based position reports using the registered first plurality of radar-based position reports as a reference.