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