Patent ID: 11872042
Assignee: HI LLC
Field: Measurement (Instruments)
Classification: CPC A  G | IPC A  G

Claim 1:
2. The calibration system of claim 1,
wherein the magnetometer is a vector magnetometer comprising a plurality of scalar magnetometers having a plurality of unknown gains, and the at least one calibration coil is oriented relative to the plurality of scalar magnetometers of the vector magnetometer, such that the calibrating magnetic field generated by the at least one calibration coil has a plurality of directional components of known amplitudes at the plurality of scalar magnetometers of the vector magnetometer, and the acquired calibrating magnetic field measurement reported by the magnetometer comprises an acquired plurality of directional components of the calibrating magnetic field measurement reported by the plurality of scalar magnetometers of the vector magnetometer;
wherein the calibration frequency is outside of linear operating ranges of the plurality of scalar magnetometers;
wherein the memory is configured for storing a plurality of roll-off gain errors of the plurality of scalar magnetometers characterizing roll-off effects of gains of the scalar magnetometers at the reference frequency within the linear operating ranges of the plurality of scalar magnetometers and gains of the plurality of scalar magnetometers at the calibration frequency; and
wherein the at least one processor is configured for:
recalling the roll-off gain error of the magnetometer from the memory by recalling the plurality of roll-off gain errors of the plurality of scalar magnetometers from the memory;
computing the product of the known amplitude of the calibrating magnetic field at the magnetometer and the roll-off gain error of the magnetometer by computing a plurality of products of the known amplitudes of the plurality of directional components of the calibrating magnetic field generated by the at least one calibration coil at the plurality of scalar magnetometers and the plurality of recalled roll-off gain errors of the plurality of scalar magnetometers;
computing the ratio of the amplitude of the acquired calibrating magnetic field measurement reported by the magnetometer and the known amplitude of the calibrating magnetic field at the magnetometer by computing a plurality of ratios between the acquired plurality of directional component measurements of the calibrating magnetic field reported by the plurality of scalar magnetometers of the vector magnetometer and the plurality of computed products; and
determining the unknown gain of the magnetometer by determining the plurality of unknown gains of the plurality of scalar magnetometers of the vector magnetometer at least partially based on computed plurality of ratios.