Antenna array calibration

A calibration method for an antenna array having a plurality of antennas including at least a first antenna and a second antenna, the method comprising:

• selecting, using at least one processor, a first signal received by the first antenna from a calibration satellite from amongst signals received from the plurality of antennas;
• selecting, using the at least one processor, a second signal received by the second antenna from the calibration satellite from amongst the signals received from the plurality of antennas;
• measuring a first phase of the first signal received by the first antenna and a second phase of the second signal received by the second antenna using a global navigation satellite system receiver;
• receiving, by the at least one processor, the first phase and the second phase from the global navigation system receiver;
• determining, using the at least one processor, a difference between the first and second phases;
• obtaining, from at least one computer readable medium, an expected phase difference between signals received by the first and second antennas;
• determining, using the at least one processor, a phase correction by comparing the difference between the first and second phases with the expected phase difference;
• and
• producing, using the at least one processor, a plurality of beamformed signals, each beamformed signal being produced for a respective satellite of a plurality of satellites by phase-adjusting and combining the signals received from the plurality of antennas, wherein said phase-adjusting is performed based at least in part on the determined phase correction.

A non-transitory computer readable storage medium having stored thereon instructions, which, when executed by at least one processor, perform a calibration method for an antenna array having a plurality of antennas including at least a first antenna and a second antenna, the method comprising:

• selecting, using the at least one processor, a first signal received by the first antenna from a calibration satellite from amongst signals received from the plurality of antennas;
• selecting, using the at least one processor, a second signal received by the second antenna from the calibration satellite from amongst the signals received from the plurality of antennas;
• in response to providing the first signal and the second signal to a global navigation satellite system receiver and the global navigation satellite system receiver measuring the phases of the first signal and the second signal as a first phase and a second phase, respectively, receiving the first phase and the second phase from the global navigation satellite system receiver;
• determining, using the at least one processor, a difference between the first and second phases;
• obtaining, from at least one computer readable medium, an expected phase difference between signals received by the first and second antennas;
• determining, using the at least one processor, a phase correction by comparing the difference between the first and second phases with the expected phase difference;
• and
• producing, using the at least one processor, a plurality of beamformed signals, each beamformed signal being produced for a respective satellite of a plurality of satellites by phase-adjusting and combining the signals received from the plurality of antennas, wherein said phase-adjusting is performed based at least in part on the determined phase correction.

An apparatus for performing calibration of an antenna array having a plurality of antennas including at least a first antenna and a second antenna, the apparatus comprising:

• at least one computer readable medium;
• a global navigation satellite system receiver configured to measure a first phase of a first signal received by the first antenna from a satellite and a second phase of a second signal received by the second antenna from the satellite;
• and
• at least one processor configured to:
• receive the first phase and the second phase from the global navigation satellite system receiver;
• determine a difference between the first and second phases;
• obtain, from the at least one computer readable medium, an expected phase difference between signals received by the first and second antennas;
• determine a phase correction by comparing the expected phase difference with the determined difference between the first and second phases;
• and
• perform beamsteering of the first signal received by the first antenna from the satellite and of the second signal received by the second antenna from the satellite by adjusting the first phase of the first signal and the second phase of the second signal based at least in part on the determined phase correction.