An optical shape sensing system employing an optical fiber (20) and one or more reference markers (41). Each reference marker (41) has an identifiable reference tracking position within a reference coordinate system (42). The optical fiber (20) has a reconstruction launch point (21)within the reference coordinate system (42) serving as a basis for an execution of a shape reconstruction of the optical fiber (20) within the reference coordinate system (42). The reconstruction launch point (21)of the optical fiber (20) has a known spatial relationship with each reference marker (41) to facilitate an identification of the reconstruction launch point (21)within the reference coordinate system (42).
