Radar apparatus and alignment sensor

• US 7,884,772 B2
• Filed: 05/07/2007
• Issued: 02/08/2011
• Est. Priority Date: 05/07/2007
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Granat, Stanley M., Hall, Richard R.
• Primary Examiner(s): CHEN, SHIH CHAO
• Application Number:
  US11/800,600
• Publication Number:
  US 20080278386A1
• Time in Patent Office: 1,373 Days
• Field of Search: 343/703, 343/757, 343/761, 343/760
• US Class Current: 343/703
• CPC Class Codes: G01S 13/87 Combinations of radar systems, e.g. primary radar and secondary radar
• 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 1/1235 Collapsible supports; Means for erecting a rigid antenna
• CPC Class Codes: H01Q 3/02 using mechanical movement of antenna or antenna system as a whole
• CPC Class Codes: H01Q 3/267 Phased-array testing or checking devices

Abstract

A radar apparatus including: a radar antenna array; and, a sensor for detecting a relative distortion of at least one portion of the radar antenna relative to at least one other portion of the radar antenna array.

Claims

1. A radar apparatus comprising:

a radar antenna array;

a sensor for detecting a relative distortion of at least one portion of the radar antenna array relative to at least one other portion of the radar antenna array;

at least one source of electromagnetic radiation emissions, and

a plurality of reflectors coupled to the radar antenna array and positioned to reflect emission from the at least one source to the sensor.

2. The radar apparatus of claim 1, wherein the sensor comprises at least one interferometer.

3. The radar apparatus of claim 1, wherein the sensor comprises a plurality of interferometers.

4. The radar apparatus of claim 1, further comprising at least one processor coupled to the sensor.

5. The radar apparatus of claim 1, wherein the sensor comprises at least one photo detector array coupled to the radar antenna array.

6. The radar apparatus of claim 1, wherein the radar antenna array is substantially planar, and the sensor detects radar antenna variation therefrom.

7. A radar apparatus comprising:

a radar antenna array;

a sensor for detecting a relative distortion of at least one portion of the radar antenna array relative to at least one other portion of the radar antenna array; and

at least one actuator coupled to the antenna array and responsive to the sensor to mitigate at least one sensed distortion.

8. The radar apparatus of claim 7, wherein the sensor comprises a plurality of load cells coupled to the radar antenna array.

9. The radar apparatus of claim 7, wherein the sensor comprises a plurality of strain gages coupled to the radar antenna array.

10. The radar apparatus of claim 7, wherein the sensor comprises at least one quadrant detector coupled to the radar antenna array.

11. The radar apparatus of claim 7, wherein the sensor comprises a plurality of accelerometers coupled to the radar antenna array.

12. A method for use with a radar antenna array, comprising:

detecting a relative distortion of at least one portion of the radar antenna array relative to at least one other portion of the radar antenna array;

providing an output dependently upon the detecting, and

outputting a confidence level indicator representing the estimated accuracy of received signals as a function of detected distortion.

13. The method of claim 12, further comprising biasing the radar antenna array responsively to the output.

14. The method of claim 12, wherein the output is indicative of an amount of detected distortion.

15. The method of claim 12, wherein the detecting comprises:

determining distances to a plurality of points on the radar antenna array; and

,

comparing the distances to known distances.

16. An alignment sensing system for a radar antenna array comprising:

a sensor arrangement operatively coupled to the radar antenna array, the sensor arrangement comprising at least one interferometer responsive to at least one electromagnetic radiation source, the sensor arrangement sensing deviations in positions of one or more of the portions of said array relative to a set of predetermined positions associated with said one or more portions and generating signals indicative of said deviations; and

a processor responsive to said signals output from said sensor arrangement for adjusting radar parameters to compensate for said sensed deviations in position of said array.

17. The system of claim 16, wherein said adjusted radar parameters include one or more of elevation, azimuth, range and velocity.

18. The system of claim 16, wherein said sensor arrangement comprises at least one reflector.

19. The system of claim 16, wherein the radar antenna array comprises a foldable antenna array.

20. The system of claim 16, wherein the at least one electromagnetic radiation source is generally co-located with the at least one interferometer.

22. The system of claim 18, wherein the at least one reflector comprises a plurality of reflectors.

23. The system of claim 22, wherein the at least one interferometer comprises a plurality of interferometers, each interferometer configured to receive an electromagnetic signal reflected off at least one of the plurality of reflectors.

24. The system of claim 22, further comprising at least one beam splitter, the at least one beam splitter responsive to the at least one radiation source for providing an electromagnetic signal to each of the plurality of reflectors.

21. A radar apparatus comprising:

a radar antenna array;

a sensor for detecting a relative distortion of at least one portion of the radar antenna array relative to at least one other portion of the radar antenna array;

at least one processor coupled to the sensor, the processor configured to output a confidence level indicator representing the estimated accuracy of received signals as a function of detected distortion.