A method of calibrating an inertial measurement unit, the method comprising: (a) collecting data from the inertial measurement unit while stationary as a first step； (b) collecting data from the inertial measurement unit while repositioning the inertial measurement unit around three orthogonal axes of the inertial measurement unit as a second step； (c) calibrating a plurality of gyroscopes using the data collected during the first step and the second step； (d) calibrating a plurality of magnetometers using the data collected during the first step and the second step； (e) calibrating a plurality of accelerometers using the data collected during the first step and the second step； (f) where calibrating the plurality of magnetometers includes extracting parameters for distortion detection and using the extracted parameters to determine if magnetic distortion is present within a local field of the inertial measurement unit.
