Feature in antenna pattern for pointing and orientation determination

• US 9,391,356 B2
• Filed: 06/06/2013
• Issued: 07/12/2016
• Est. Priority Date: 06/06/2012
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Rochblatt, David
• Primary Examiner(s): Phan, Dao
• Application Number:
  US13/912,186
• Publication Number:
  US 20130328721A1
• Time in Patent Office: 1,132 Days
• Field of Search: 342/76, 342/77, 342/359, 342/420, 342/427, 343/757, 343/758
• US Class Current: 1/1
• CPC Class Codes: H01Q 1/1257 using the received signal strength

Abstract

Systems and methods for antenna pointing are disclosed. A transmit antenna system having an adjustable boresight transmits a signal exhibiting a far-field pattern including a feature (e.g. a V-Notch) in a polarization of the signal disposed at a fixed position off a beam peak of the far-field pattern of the signal. A receive antenna system scans across the far-field pattern of the signal in the polarization to locate the feature and determine a pointing error of the adjustable boresight therefrom. The system may be applied to a cross-polarization of the signal where a co-polarization of the signal is simultaneously used for telecommunication.

Claims

1. An apparatus for determining antenna pointing, comprising:

a transmit antenna system for transmitting a signal having an adjustable boresight and exhibiting a far-field pattern including a feature in a polarization component of the far-field pattern disposed at a fixed position off a beam peak of the far-field pattern; and

a receive antenna system for scanning across the far-field pattern in the polarization component to locate the feature and determine a pointing error of the adjustable boresight therefrom;

wherein the feature of the far-field pattern comprises a notch having a depth relative to a main lobe of the far-field pattern varying with an angle of the fixed position off the boresight.

2. The apparatus of claim 1, wherein the feature disposed at the fixed position off the beam peak of the far-field pattern is mapped with the transmit antenna system installed to include any multipath effects.

3. The apparatus of claim 1, wherein the pointing error is transmitted to the transmit antenna system and the boresight is adjusted to correct the pointing error.

4. The apparatus of claim 1, wherein the transmit antenna system is installed on a spacecraft and the receive antenna is disposed at a ground station.

5. The apparatus of claim 1, wherein the polarization component having the feature in the far-field pattern is a cross-polarization component and a co-polarization component is simultaneously used to communicate while the receive antenna system determines the pointing error.

6. The apparatus of claim 5, wherein the co-polarization component comprises a right circular polarization (RCP) and the cross-polarization component comprises a left circular polarization (LCP).

7. The apparatus of claim 1, wherein the feature in the far-field pattern of the polarization component is switchably activated.

8. The apparatus of claim 7, wherein the polarization component having the feature in the far-field pattern is a co-polarization component and the feature is only temporarily activated for the receive antenna system to determine the pointing error.

9. A method for determining antenna pointing, comprising:

transmitting a signal with a transmit antenna system having an adjustable boresight and exhibiting a far-field pattern including a feature in a polarization component of the far-field pattern disposed at a fixed position off a beam peak of the far-field pattern; and

scanning across the far-field pattern in the polarization component with a receive antenna system to locate the feature and determine a pointing error of the adjustable boresight therefrom;

wherein the feature of the far-field pattern comprises a notch having a depth relative to a main lobe of the far-field pattern varying with an angle of the fixed position off the boresight.

10. The method of claim 9, further comprising mapping the feature disposed at the fixed position off the beam peak of the far-field pattern with the transmit antenna system installed to include any multipath effects.

11. The method of claim 9, further comprising transmitting the pointing error to the transmit antenna system and adjusting the boresight to correct the pointing error.

12. The method of claim 9, wherein the transmit antenna system is installed on a spacecraft and the receive antenna is disposed at a ground station.

13. The method of claim 9, wherein the polarization component having the feature in the far-field pattern is a cross-polarization component and a co-polarization component is simultaneously used to communicate while the receive antenna system determines the pointing error.

14. The method of claim 13, wherein the co-polarization component comprises a right circular polarization (RCP) and the cross-polarization component comprises a left circular polarization (LCP).

15. The method of claim 9, wherein the feature in the far-field pattern of the polarization component is switchably activated.

16. The method of claim 15, wherein the polarization component having the feature in the far-field pattern is a co-polarization component and the feature is only temporarily activated for the receive antenna system to determine the pointing error.

17. An apparatus for determining antenna pointing, comprising:

a transmit antenna system means for transmitting a signal having an adjustable boresight and exhibiting a far-field pattern including a feature in a polarization component disposed at a fixed position off a beam peak of the far-field pattern; and

a receive antenna system means for determining a pointing error of the adjustable boresight from scanning across the far-field pattern in the polarization component to locate the feature;

wherein the feature of the far-field pattern comprises a notch having a depth relative to a main lobe of the far-field pattern varying with an angle of the fixed position off the boresight.

18. The apparatus of claim 17, wherein the feature of the far-field pattern is mapped with the transmit antenna system means installed to include any multipath effects.