A detector is configured to determine {HEAD ~ the position} of the tracking device so that the determined position of the tracking device associated with the second linkage member determines the position of {TAIL ~ the first linkage member} which is physically coupled to the trackable object 
A detector is configured to determine { HEAD ~ the position } of the tracking device so that the determined position of the tracking device associated with the second linkage member determines the position of { TAIL ~ the first linkage member } which is physically coupled to the trackable object
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH