capturing at least one image involving a calibration chart by a camera, wherein a first trackable device is physically attached to the camera, a second trackable device is physically attached to the calibration chart;

tracking the first trackable device and the second trackable device by a tracking station, to generate a first rotation-translation matrix, between the first trackable device and the tracking station, and a second rotation-translation matrix, between the second trackable device and the tracking station;

generating a third rotation-translation matrix, between a camera coordinate system of the camera and the calibration chart according to the calibration chart appeared in the at least one image; and

calculating a fourth rotation-translation matrix, between the camera coordinate system and the first trackable device, according to the first rotation-translation matrix, the second rotation-translation matrix and the third rotation-translation matrix, wherein the fourth rotation-translation matrix is utilized to track the camera.