Magnetometers are used to measure the strength of a magnetic field. They can also be used to determine orientation and to compensate gyro drift. Magnetometer provides the last three degrees of freedom in 9DOF sensors. There is one problem though, magnetometers are prone to distortion. Hard iron distortion The magnetic field used for determining the heading is the earth’s magnetic field. In addition to earth’s, there are additional magnetic fields which cause interference. Interference can...
