US Patent 12104903 Spinning hall probe compass

A high precision magnetic compass based on a Hall probe. The probe is oriented at an angle of 90 degrees to the rotation axis of the device. An oscillating component of the signal from the probe, synchronized with the device rotation, is transferred to the non-rotation frame and is used to align the axis of rotation to be parallel to the magnetic field. The device does not require prior calibration. It is insensitive to drift of the probe parameters and can provide an angle with precision equal to or better than a 0.05 degree.