Approach to improve pointing accuracy of antenna systems with offset reflector and feed configuration

• US 10,181,643 B2
• Filed: 03/05/2015
• Issued: 01/15/2019
• Est. Priority Date: 03/05/2015
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Liu, Yong
• Primary Examiner(s): Gregory, Bernarr E
• Assistant Examiner(s): Pervin, Nuzhat
• Application Number:
  US14/639,885
• Publication Number:
  US 20160261040A1
• Time in Patent Office: 1,412 Days
• Field of Search: 342359
• CPC Class Codes: H01Q 1/288 Satellite antennas
• CPC Class Codes: H01Q 1/32 Adaptation for use in or on road or rail vehicles
• CPC Class Codes: H01Q 1/34 Adaptation for use in or on ships, submarines, buoys or torpedoes for subaqueous use H01Q1/04
• CPC Class Codes: H01Q 19/132 Horn reflector antennas; Off-set feeding
• CPC Class Codes: H01Q 3/08 for varying two co-ordinates of the orientation

Abstract

Systems, methods, and apparatus for calibration for an offset antenna are disclosed. In one or more embodiments, the disclosed method involves calculating an estimated gimbal angle between the offset antenna and at least one target. Also, the method involves transmitting, by at least one target, at least one signal; and receiving, by the offset antenna, at least one signal. The method further involves pointing the offset antenna to an optimum gimbal angle to maximize received signal power. Additionally, the method involves comparing the optimum gimbal angle with the estimated gimbal angle to determine a difference in the gimbal angles. Also, the method involves calculating a bus, reflector, and/or feed error estimate by using the difference in the gimbal angles. Further, the method involves determining an azimuth and/or elevation correction for bus, reflector, and/or feed errors by using the bus, reflector, and/or feed error estimate.

Claims

1. A method for calibration for an offset antenna, the method comprising:

determining at least one target in a known location;

calculating, with at least one processor, an estimated gimbal angle between the offset antenna and at least one of the targets;

transmitting, by at least one antenna of at least one of the targets, at least one signal;

receiving, by the offset antenna, the at least one signal, wherein the offset antenna is mounted onto a vehicle;

pointing the offset antenna to an optimum gimbal angle, for at least one of the targets, to maximize received signal power of the at least one signal;

comparing, by the at least one processor, the optimum gimbal angle with the estimated gimbal angle, for at least one of the targets, to determine a difference in the gimbal angles for at least one of the targets;

calculating, by the at least one processor, a bus error estimate, a reflector error estimate, and a feed error estimate by using the difference in the gimbal angles, for at least one of the targets; and

determining, by the at least one processor, at least one of an azimuth correction and an elevation correction for gimballing a reflector of the offset antenna to correct for rotational errors between the reflector and the vehicle and to correct for translational errors between a feed of the offset antenna and the reflector by using the bus error estimate, the reflector error estimate, and the feed error estimate.

2. The method of claim 1, wherein the vehicle is one of an airborne vehicle, a terrestrial vehicle, and a marine vehicle.

3. The method of claim 2, wherein the airborne vehicle is one of a satellite, an aircraft, and a space plane.

4. The method of claim 2, wherein the terrestrial vehicle is one of a truck, a train, a car, and a tank.

5. The method of claim 2, wherein the marine vehicle is one of a ship and a boat.

6. The method of claim 1, wherein the at least one signal is an electromagnetic (EM) signal.

7. The method of claim 6, wherein the EM signal is one of a radio frequency (RF) signal, an optical signal, and an infra-red signal.

8. The method of claim 1, wherein at least one of the targets is a ground station.

16. The method of claim 1, wherein the method further comprises gimballing, with a gimbal, the reflector of the offset antenna according to at least one of the azimuth correction or the elevation correction.

9. A system for calibration for an offset antenna, the system comprising:

at least one target in a known location, wherein at least one antenna of at least one of the targets is to transmit at least one signal;

the offset antenna to receive the at least one signal, and to point to an optimum gimbal angle, for at least one of the targets, to maximize received signal power of the at least one signal,

wherein the offset antenna is mounted onto a vehicle; and

at least one processor to calculate an estimated gimbal angle between the offset antenna and at least one of the targets;

to compare the optimum gimbal angle with the estimated gimbal angle, for at least one of the targets;

to determine a difference in the gimbal angles for at least one of the targets;

to calculate a bus error estimate, a reflector error estimate, and a feed error estimate by using the difference in the gimbal angles, for at least one of the targets; and

to determine at least one of an azimuth correction and an elevation correction for gimballing a reflector of the offset antenna to correct for rotational errors between the reflector and the vehicle and to correct for translational errors between a feed of the offset antenna and the reflector by using the bus error estimate, the reflector error estimate, and the feed error estimate.

10. The system of claim 9, wherein the vehicle is one of an airborne vehicle, a terrestrial vehicle, and a marine vehicle.

11. The system of claim 10, wherein the airborne vehicle is one of a satellite, an aircraft, and a space plane.

12. The system of claim 10, wherein the terrestrial vehicle is one of a truck, a train, a car, and a tank.

13. The system of claim 10, wherein the marine vehicle is one of a ship and a boat.

14. The system of claim 9, wherein the at least one signal is an electromagnetic (EM) signal.

15. The system of claim 14, wherein the EM signal is one of a radio frequency (RF) signal, an optical signal, and an infra-red signal.

17. The system of claim 9, wherein the system further comprises a gimbal to gimbal the reflector of the offset antenna according to at least one of the azimuth correction or the elevation correction.