Method for estimating the position and orientation using an inertial measurement unit fixed to a moving pedestrian

The method is for estimating the position and orientation using an inertial measurement unit fixed to a moving pedestrian, in particular to a leg, a knee, a foot, or an arm of a pedestrian, for detecting movement of the pedestrian within an observation area in particular not being covered by GNSS-signals as e.g. in buildings. The method comprises the following steps assuming a known sensor alignment on the pedestrian: - receiving measurements values from the inertial measurement unit and determining the orientation of the pedestrian within the observation area, - providing a magnetic field sensor fixed to the pedestrian, for sensing at least the direction of the local magnetic field at the respective site within the observation area where the pedestrian currently is present, - determining the orientation of the pedestrian within the observation area based on the direction of the local magnetic field sensed by the magnetic field sensor, and - adjusting orientation estimated by the inertial measurement unit in accordance with the information obtained from the discrepancies between the change in orientation provided by the inertial measurement unit and the change in orientation of the pedestrian observed from the local magnetic field, sensed by the magnetic field sensor.