Reference terrain altitude maps are converted by a reference map transformation to {HEAD ~ data} which correlates {TAIL ~ the reference map} to the altitude of the missile 
correlates
Reference terrain altitude maps are converted by a reference map transformation to { HEAD ~ data } which correlates { TAIL ~ the reference map } to the altitude of the missile
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH