Conversion apparatus and method for magnetic compass systems

Claim 1

CONVERSION APPARATUS FOR MAGNETIC COMPASS SYSTEMS FOR NAVIGABLE CRAFT COMPRISING: (1) MEANS RESPONSIVE TO THE EARTH''S MAGNETIC FIELD FOR PROVIDING A SIGNAL REPRESENTATIVE OF THE MAGNETIC HEADING OF SAID CRAFT, (2) MEANS FOR PROVIDING A SIGNAL REPRESENTATIVE TO THE MAGNETIC VARIATION AND MERIDIAN CONVERGENCE WITH RESPECT TO A PREDETERMINED COORDINATE SYSTEM AT A PREDETERMINED POSITION OF SAID CRAFT, (3) MEANS FOR ESTABLISHING A REFERENCE REPRESENTATIVE OF THE DIRECTION OF THE GRADIENT WITH RESPECT TO DISTANCE OF THE EARTH''S MAGNETIC VARIATIONS AND MERIDIAN CONVERGENCE, (4) MEANS RESPONSIVE TO THE MOVEMENT OF SAID CRAFT FROM SAID PREDETERMINED POSITION TO SAID GRADIENT DIRECTION REFERENCE FOR PROVIDING A SIGNAL REPRESENTATIVE OF THE COMPONENT OF THE DISTANCE TRAVELED BY SAID CRAFT IN THE DIRECTION OF MAXIMUM RATE OF CHANGE OF SAID MAGNETIC VARIATION AND MERIDIAN CONVERGENCE, (5) MEANS FOR PROVIDING A SIGNAL REPRESENTATIVE OF THE MAGNITUDE OF SAID GRADIENT, (6) AND MEANS RESPONSIVE TO ALL OF SAID SIGNALS FOR PROVIDING A COMPOSITE SIGNAL REPRESENTATIVE OF THE PRESENT HEADING OF THE CRAFT WITH RESPECT TO SAID PREDETERMINED COORDINATE SYSTEM CORRECTED FOR MAGNETIC VARIATION AND MERIDIAN CONVERGENCE AT THE PRESENT POSITION OF SAID CRAFT.