A method and {TAIL ~ apparatus} for determining the relative positions of a first object and {HEAD ~ a second object}  
A method and { TAIL ~ apparatus } for determining the relative positions of a first object and { HEAD ~ a second object }
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH