REAL TIME DETERMINATION OF PEDESTRIAN DIRECTION OF TRAVEL

Embodiments are disclosed for real time estimation of DoT. In some embodiments, a method comprises: obtaining inertial acceleration data from a motion sensor of a mobile device worn or held by a user; computing a frequency spectrum of the acceleration data to generate horizontal and vertical frequency components at a step frequency of the user; constructing an acceleration trajectory of the horizontal frequency components in a horizontal reference frame, the horizontal frequency components forming an ellipse in the horizontal reference frame; determining a maximum radius vector of the ellipse; determining an angle to DoT based on the maximum radius vector; disambiguating a sign of the angle; and determining the disambiguated angle as the DoT.