1. A method of determining directional calibration parameters of an object to be tracked, the method comprising: a) disposing a tracking marker over the object, disposing the object over a calibration tool, and disposing the tracking marker in a traceable region for a position tracking apparatus; b) rotating the object around a set straight line as an axis, while keeping the direction of the straight line unchanged in a three-dimensional space; c) during rotation of the object, obtaining at least two groups of rotation status parameters of the tracking marker in at least two different rotation positions, and based on the at least two groups of rotation status parameters, determining at least two three-dimensional rotation matrices for computing directional calibration parameters; d) with the three-dimensional rotation matrices determined from step c), solving simultaneous equations to compute the directional calibration parameters for a set direction of the object.