Geographic coordinate-indicating navigation apparatus for hyperbolic systems

Claim 1

APPARATUS FOR USE IN THE NAVIGATION OF A MOBILE CRAFT WITH POSITION FINDING RADIO SYSTEMS OF THE HYPERBOLIC TYPE COMPRISING MEANS FOR PROVIDING A PAIR OF SIGNALS REPRESENTATIVE OF PATH-LENGTH DIFFERENCES FROM SAID CRAFT TO TWO PAIRS OF GEOGRAPHIC REFERENCE POINTS, SETTABLE MEANS FOR PROVIDING: A PAIR OF SIGNALS REPRESENTATIVE OF THE COORDIANTES OF A GEOGRAPHIC REFERENCE POINT MIDWAY ON A LINE BETWEEN ONE PAIR OF SAID REFERENCE POINTS IN A CARTESIAN GRID SYSTEM BASED ON THE OTHER PAIR OF SAID POSITIONS; A SIGNAL REPRESENTATIVE OF THE ANGULAR INCONGRUENCE BETWEEN SAID LINE AND AN AXIS OF SAID GRID SYSTEM; AND A PAIR OF SIGNALS REPRESENTATIVE OF THE SEMI-BASE DISTANCES OF THE PAIR OF HYPERBOLAE INTERSECTING IN THE CRAFT POSITION AND BASED ON RESPECTIVE PAIRS OF SAID STATIONS; AND COMPUTING MEANS RESPONSIVE TO ALL OF SAID SIGNALS JOINTLY FOR CONTINUOUSLY INDICATING THE POSITION OF SAID CRAFT IN SAID GRID SYTEM.