{HEAD ~ A detector} is configured to determine {TAIL ~ 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 the first linkage member which is physically coupled to the trackable object 
is configured to determine
{ HEAD ~ A detector } is configured to determine { TAIL ~ 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 the first linkage member which is physically coupled to the trackable object
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH