In accordance with this invention, generally stated, {HEAD ~ a navigation system} for a vehicle is provided with {TAIL ~ terrain correlation} embodied in a construction which is independent of vehicle altitude and which permits curvilinear vehicle course paths 
is provided with
In accordance with this invention , generally stated , { HEAD ~ a navigation system } for a vehicle is provided with { TAIL ~ terrain correlation } embodied in a construction which is independent of vehicle altitude and which permits curvilinear vehicle course paths
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH 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