Methods and systems of adaptive antenna pointing for mitigating interference with a nearby satellite
Systems and methods are described herein for adaptive pointing operations of a mobile antenna system that can be used to provide communication with a target satellite over a large geographical area, while also satisfying interference requirements with one or more other satellites. In particular, the adaptive pointing operations described herein control pointing of a beam of the antenna system towards the target satellite in a manner that takes into consideration the interference requirements of the other satellites. In some embodiments, the mobile antenna system can provide non-interfering communication with the target satellite, over the entire or substantially the entire coverage area (or footprint) of the target satellite. In doing so, services such as Internet, telephone and/or television services provided by the target satellite can be delivered to users throughout most or all of the satellite's coverage area, while also satisfying interference requirements with other satellites.
1. A method comprising:
pointing a beam of an antenna on a mobile vehicle in a target direction at a target satellite and communicating a signal with the target satellite via the antenna, the beam having an asymmetric beam pattern with a wide beamwidth axis and a narrow beamwidth axis in the target direction;
determining that an amount of interference in a non-target direction reaches a threshold due to the wide beamwidth axis of the asymmetric beam pattern; and
in response to the determination, adjusting pointing of the beam to an offset direction away from the non-target direction and away from the target direction, and further communicating the signal with the target satellite via the antenna.
2. The method of claim 1 , wherein the threshold is a first threshold, and further comprising:
re-pointing the beam of the antenna in the target direction at the target satellite when the amount of interference in the non-target direction is below a second threshold.
3. The method of claim 1 , wherein the offset direction is such that the amount of interference in the non-target direction remains at or below the threshold.
4. The method of claim 3 , further comprising changing the offset direction due to changes in geographic location of the mobile vehicle.
5. The method of claim 1 , wherein a non-target satellite is in the non-target direction.
6. The method of claim 5 , wherein:
the target satellite and the non-target satellite are each geostationary satellites along a geostationary arc; and
the adjusting pointing of the beam to the offset direction is based at least in part on a skew angle between the asymmetric beam pattern and the geostationary arc reaching a predetermined value.
7. The method of claim 1 , wherein the communicated signal is an uplink signal transmitted from the mobile vehicle to the target satellite.
8. The method of claim 1 , wherein the mobile vehicle is an aircraft.
9. An antenna system for mounting on a mobile vehicle, the antenna system comprising:
an antenna having a beam for communicating a signal with a target satellite, the beam having an asymmetric beam pattern with a wide beamwidth axis and a narrow beamwidth axis;
a pointing adjustment mechanism to adjust pointing of the beam of the antenna; and
an adaptive pointing system to control transition of the pointing adjustment mechanism from a first operational mode to a second operational mode in response an amount of interference in a non-target direction reaching a threshold due to the wide beamwidth axis of the asymmetric beam pattern, wherein:
in the first operational mode, the pointing adjustment mechanism points the beam of the antenna in a target direction at the target satellite; and
in the second operational mode, the pointing adjustment mechanism adjusts pointing of the beam to an offset direction away from the non-target direction and away from the target direction.
10. The antenna system of claim 9 , wherein:
the threshold is a first threshold; and
the adaptive pointing system further controls transition of the pointing adjustment mechanism from the second operational mode to the first operational mode in response to an amount of interference in a non-target direction reaching a second threshold.
11. The antenna system of claim 9 , wherein the offset direction is such that the amount of interference in the non-target direction remains at or below the threshold.
12. The antenna system of claim 11 , wherein in the second operational mode, the adaptive pointing system controls changing the offset direction due to changes in a current geographic location of the mobile vehicle.
13. The antenna system of claim 9 , wherein a non-target satellite is in the non-target direction.
14. The antenna system of claim 13 , wherein:
the target satellite and the non-target satellite are each geostationary satellites along a geostationary arc; and
the adaptive pointing system controls transition of the pointing adjustment mechanism from the first operational mode to the second operational mode when a skew angle between the asymmetric beam pattern and the geostationary arc reaches a predetermined value.
15. The antenna system of claim 9 , wherein the communicated signal is an uplink signal transmitted from the mobile vehicle to the target satellite.
16. The antenna system of claim 9 , wherein the communicated signal is an uplink signal transmitted from the mobile vehicle to the target satellite.