Patent ID: 11965944
Assignee: APPLE INC.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 9:
10. A method performed by a receiver of a magnetic tracking system, comprising:
obtaining, using one or more processors of the receiver, first sensor data from one or more inertial sensors of the receiver;
obtaining, using the one or more processors, second sensor data from a direct current (DC) magnetometer of the receiver;
determining, using the one or more processors, an attitude of the receiver based on the first and second sensor data;
computing, using the one or more processors, a receiver rotation transform based on the attitude of the receiver;
obtaining, using a wireless transceiver, an attitude of a transmitter and a clock sync signal for syncing communication between the receiver and the transmitter;
computing, using the one or more processors, a transmitter rotation transform based on the attitude of the transmitter;
computing, using the one or more processors, a position of the receiver by:
measuring a magnetic field emitted by the transmitter;
multiplying the measured magnetic field vector by the receiver rotation transform to obtain magnetic field vector components of a dipole model in a reference coordinate frame;
multiplying a dipole moment by the transmitter rotation transform to obtain dipole moment components of the dipole model in the reference coordinate frame; and
determining, using the dipole model, the receiver position.