Patent ID: 11860246
Assignee: APPLE INC.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A method comprising:
determining whether a device operating in an environment is a first threshold distance or a second threshold distance from a magnetic source in the environment, the magnetic source configured to generate a stationary magnetic field in the environment that is independent of ambient magnetic fields in the environment, where the first threshold distance is different than the second threshold distance;
in accordance with the device being the first threshold distance from the magnetic source, configuring a first set of at least two magnetometers in a sensing array of the device that are separated by a first distance to measure a change in the stationary magnetic field over the first threshold distance;
in accordance with the device being the second threshold distance from the magnetic source, configuring a second set of at least two magnetometers separated by a second distance to measure the change in the stationary magnetic field over the second threshold distance, where the second distance is greater than the first distance;
obtaining, by the sensing array of the device, a measurement of the stationary magnetic field in the environment;
determining, by one or more processors of the device, a first change in the stationary magnetic field over time based on the measurement;
determining, by the one or more processors, a second change in the stationary magnetic field over the first or second threshold distance based on the measurement;
obtaining, by the one or more processors, a rotation angle of the device;
determining, by the one or more processors, a velocity of the device in the environment based on the first change in the magnetic field over time, the second change in the magnetic field over the first or second threshold distance and the rotation angle of the device; and
integrating, by the one or more processors, the velocity to obtain a position of the device in the environment.