Magnetometer accuracy and use

An apparatus, comprising:

• a magnetometer;
• and
• a processor coupled to the magnetometer, the processor configured for:
• determining a first instance of a parameter related to Earth's magnetic field using first data generated by the magnetometer, the first data based at least in part on a position of the mobile device with respect to the Earth;
• determining a second instance of the parameter using second data generated by a model of Earth's magnetic field, the second data based at least in part on the position of the mobile device with respect to the Earth;
• comparing the first instance of the parameter with the second instance of the parameter;
• determining an accuracy metric for the magnetometer based on results of the comparison;
• and
• presenting an indication of the accuracy metric on the mobile device.

A computer-readable, non-transitory medium having instructions stored thereon, which, when executed by a processor, causes at least one processor to perform operations comprising:

• determining a first instance of a parameter related to Earth's magnetic field using first data generated by the magnetometer, the first data based at least in part on a position of the mobile device with respect to the Earth;
• determining a second instance of the parameter using second data generated by a model of Earth's magnetic field, the second data based at least in part on the position of the mobile device with respect to the Earth;
• comparing the first instance of the parameter with the second instance of the parameter;
• determining an accuracy metric for the magnetometer based on results of the comparison;
• and
• presenting an indication of the accuracy metric on the mobile device.

An apparatus, comprising:

• a magnetometer;
• and
• a processor coupled to the magnetometer, the processor configured for:
• determining an accuracy metric based on magnetometer measurements output by the magnetometer during a calibration or recalibration procedure;
• and
• presenting an indication of the accuracy metric on the mobile device.