The location and {HEAD ~ orientation} of the device relative to the origin and initial orientation is derived based on {TAIL ~ the movement data} 
The location and { HEAD ~ orientation } of the device relative to the origin and initial orientation is derived based on { TAIL ~ the movement data }
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL