| 主权项 |
1. An apparatus for determining a bias of a sensor, comprising:
at least one processor and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to perform operations comprising: acquiring results of a set of Earth's magnetic field, EMF, measurements, wherein each EMF measurement is performed by a magnetometer comprised in a mobile device and indicates a measured EMF value with respect to the orientation of the mobile device at a measurement time; acquiring motion data indicating the angular rotation that the mobile device experienced during each of a plurality of EMF measurement pairs, wherein each EMF measurement pair indicates a measured first and a second EMF value and the motion data is measured by at least one motion sensor comprised in the mobile device; determining a bias estimate of the magnetometer on the basis of the plurality of EMF measurement pairs and the corresponding motion data by finding the bias estimate that minimizes distances between the measured second EMF values and the measured first EMF values rotated about the bias estimate by the corresponding angular rotations; and determining a correction factor corresponding to the bias estimate and applying the correction factor to the magnetometer readings. |
