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