An apparatus and a method for ascertaining object kinematics of a movable object include: a trajectory calculation filter for calculating an estimated movement direction of the object based on a predicted position of the object and based on a position of the object specified in radar measurement data of the object; and a calculation unit for calculating Cartesian speeds of the object depending on a measured radial object speed and a measured object angle, which are specified in the radar measurement data, and depending on the estimated movement direction of the object that is calculated in the trajectory calculation filter.