DR. ROBERT CLARK HENDERSON, D.D.S.
Dentist at Governor Dr, San Diego, CA

4700307, Oct 13, 1987

Jul 11, 1983

6/514210

Barend Mons - Solana Beach CA
Donald H. Flowers - La Mesa CA
Robert L. Henderson - San Diego CA

General Dynamics Corp./Convair Division - San Diego CA

G01F 1550

364453

A method of navigating an airborne vehicle using observation of linear features such as roads, railroads, rivers or the like. Maps of linear features in several discrete areas along an intended flight path are prepared and entered into an on-board computer memory. The vehicle typically uses an inertial navigation system during flight from the origin to the first mapped area. Imaging sensors and on-board processing detect linear features as the vehicle approaches or passes over them. The sensed feature pattern network is compared to the reference mapped feature network to update the inertial navigation system to generate guidance commands. Frequent updates at other mapped areas keep the vehicle on course. This system is also capable of navigation updates from single linear features when the flight path is fairly well known, and of tracking a linear feature for terminal guidance. In these cases, only a small number of feature parameters need to be stored, rather than an area map.