Radar apparatus calibration via individual radar components

• US 8,704,705 B2
• Filed: 03/16/2011
• Issued: 04/22/2014
• Est. Priority Date: 03/16/2011
• Status: Active Grant

• Current Assignee: SRC, Inc.
• Original Assignee: SRC, Inc.
• Inventors: Dougherty, John Charles, Fontanella, Jeffrey John
• Primary Examiner(s): Barker, Matthew M
• Application Number:
  US13/049,213
• Publication Number:
  US 20120235858A1
• Time in Patent Office: 1,133 Days
• Field of Search: 342165-174
• US Class Current: 342/169
• CPC Class Codes: G01S 2013/0245 Radar with phased array antenna
• CPC Class Codes: G01S 7/4026 Antenna boresight
• CPC Class Codes: G01S 7/403 in azimuth, i.e. in the horizontal plane
• CPC Class Codes: G01S 7/4034 in elevation, i.e. in the vertical plane
• CPC Class Codes: H01Q 21/205 providing an omnidirectional coverage turnstile aerials H01Q21/26
• CPC Class Codes: H01Q 3/242 Circumferential scanning
• CPC Class Codes: H01Q 3/267 Phased-array testing or checking devices

Abstract

A method, system and computer program product for calibrating and operating a radar apparatus provides for obtaining calibration response data from, for example, a radar cylinder and a plurality of radar columns, prior to assembling the radar cylinder and plurality of radar columns into an assembled radar apparatus. The calibration response data for the exemplary radar cylinder and the plurality of radar columns is evaluated to provide a simulated response of the assembled radar apparatus. Actual measured responses from the assembled radar apparatus may then be correlated with the simulated response through use of a look-up table. The particular method, system and program product for calibrating and operating the radar apparatus provides for avoidance of field calibration of the assembled radar apparatus, which is generally neither desirable nor feasible under hostile conditions.

Claims

1. A method for operating a radar apparatus comprising:

determining for a plurality of radar components a plurality of laboratory test electrical responses;

determining from the plurality of laboratory test electrical responses a simulated radar response for an assembled radar apparatus assembled from the plurality of radar components;

assembling the plurality of radar components to provide the assembled radar apparatus; and

determining the location of a target by correlating a measured response of the assembled radar apparatus with the simulated radar response.

2. The method of claim 1 wherein the determining the simulated radar response uses the rotational matrix and translation:

3. The method of claim 1 wherein the determining the simulated radar response includes:

applying an amplitude and phase weight from a radar cylinder electrical response to a far field azimuth and elevation pattern for each of a plurality of radar column electrical responses;

determining simulated sum and delta beams for the radar apparatus assembled geometry from the complete azimuth and elevation beam response;

determining simulated monopulse ratios from the simulated sum and delta beams; and

converting the simulated monopulse ratios to a look-up table.

4. The method of claim 3 wherein the correlating the measured response of the assembled apparatus with the simulated radar response utilizes the look-up table of simulated monopulse ratios.

5. The method of claim 1 wherein the determining the location of the target involves selection from two or less possible target locations predicated upon a phase ratio of the measured response.

6. A method for operating a radar apparatus comprising:

determining a radar cylinder electrical response for an individual radar cylinder in a test fixture;

determining a plurality of radar column electrical responses for each of a plurality of individual radar columns in a test fixture;

determining from the radar cylinder electrical response and the plurality of radar column electrical responses a simulated radar response for an assembled radar apparatus assembled from the radar cylinder and the plurality of radar columns;

assembling the individual radar column and the plurality of radar columns to provide the assembled radar apparatus; and

determining the location of a target by correlating a measured response of the assembled radar apparatus with the simulated radar response.

7. The method of claim 6 wherein the determining the radar cylinder electrical response includes determining amplitude and phase weights of the radar cylinder for each of the plurality of radar columns and their positions in the cylinder and individual beams.

8. The method of claim 7 wherein the determining the plurality of radar column electrical responses includes determining far field azimuth and elevation patterns for each of the plurality of radar columns.

9. The method of claim 6 wherein the determining the simulated radar response uses the rotational matrix and translation:

10. The method of claim 9 wherein the determining the simulated radar response for the radar apparatus includes:

applying the amplitude and phase weights from the radar cylinder electrical response to the far field azimuth and elevation patterns for each of the radar column electrical responses;

determining simulated sum and delta beams for the radar apparatus assembled geometry from the complete azimuth and elevation beam response;

determining simulated monopulse ratios from the simulated sum and delta beams; and

converting the simulated monopulse ratios to a look-up table and phase ratios.

11. The method of claim 10 wherein the correlating the actual response with the simulated radar response correlates measured monopulse ratios to the look-up table.

12. The method of claim 6 wherein the determining the location of the target includes selecting a particular target location from a plurality of possible simulated target locations predicated upon a phase of the measured response.

13. A radar system comprising:

a radar apparatus comprising a plurality of components; and

a computer programmed to;

receive for the plurality of components a plurality of laboratory test electrical responses;

determine from the plurality of laboratory test electrical responses a simulated radar response for an assembled radar apparatus assembled from the plurality of radar components; and

determine the location of a target by correlating a measured response of the assembled radar apparatus with the simulated radar response.

14. The radar system of claim 13 wherein the determining the simulated radar response uses the rotational matrix and translation:

15. The radar system of claim 14 wherein the determining of the simulated radar response for the radar apparatus includes:

applying the amplitude and phase weights from a radar cylinder electrical response to a plurality of far field azimuth and elevation patterns for each of a plurality of radar column electrical responses;

determining simulated sum and delta beams for the radar apparatus assembled geometry from the complete azimuth and elevation beam response;

determining simulated monopulse ratios from the simulated sum and delta beams; and

converting the simulated monopulse ratios to a look-up table.

16. The radar apparatus of claim 15 wherein the correlating the measured response of the assembled radar apparatus with the simulated radar response utilizes the look-up table of simulated monopulse ratios.

17. The radar apparatus of claim 13 wherein the determining the location of the target involves selection from a plurality of possible target locations predicated upon a phase of the measured response.

18. A non-transitory computer readable medium having instructions stored thereon which, when executed by at least one processor cause a computer to:

receive for a plurality of radar components a plurality of laboratory test electrical responses;

determine from the plurality of laboratory test electrical responses a simulated radar response for an assembled radar apparatus assembled from the plurality of radar components; and

determine the location of a target by correlating a measured response of the assembled radar apparatus with the simulated radar response.

19. The non-transitory computer readable medium of claim 18 wherein the determining the simulated radar response uses the rotational matrix and translation:

20. The non-transitory computer readable medium of claim 19 wherein the determining the simulated radar response for the radar apparatus includes:

applying the amplitude and phase weights from a radar cylinder electrical response to a plurality of far field azimuth and elevation patterns for each of a plurality of radar column electrical responses;

determining simulated sum and delta beams for the radar apparatus assembled geometry from the complete azimuth and elevation beam response;

determining simulated monopulse ratios from the simulated sum and delta beams; and

converting the simulated monopulse ratios to a look-up table.

21. The non-transitory computer readable medium of claim 20 wherein the correlating the measured response of the assembled apparatus with the simulated radar response utilizes the look-up table of simulated monopulse ratios.

22. The non-transitory computer readable medium of claim 18 wherein the determining the location of the target involves selection from a plurality of possible target locations predicated upon a phase of the measured response.