Air traffic schedule monitoring method and system

Claim 1

IN A DISPLAY DEVICE FOR USE WITH AN AIRCRAFT CONTROL SYSTEM WHEREIN A PLURALITY OF AIRCRAFT ARE DIRECTED THROUGH A LANDING SYSTEM ENTRY GATE ON PREDETERMINED AND ASSIGNED SCHEDULES, AND WHEREIN A STAIRCASE REFERENCE SIGNAL PROPORTIONAL TO SELECTED TIMES TO ARRIVAL OF AIRCRAFT APPROACHING THE ENTRY GATE IS GENERATED ON A TIME SHARED BASIS AND SYNCHRONOUSLY WITH A SYNCHRONIZING PULSE AND A PLURALITY OF GATING SIGNALS REPRESENTATIVE OF THE STATUS OF A PARTICULAR TIME-TO-ARRIVAL SCHEDULE, THE DISPLAY DEVICE INCLUDING A CATHODE-RAY TUBE HAVING FIRST AND SECOND SWEEP CIRCUITS, AN ARRANGEMENT FOR CONTROLLING THE CATHODE-RAY TUBE BEAM INTENSITY, SAID ARRANGEMENT COMPRISING: MEANS COUPLED TO THE FIRST SWEEP CIRCUIT FOR SAMPLING THE STAIRCASE REFERENCE SIGNAL AND THE STROBE SIGNAL ONCE EACH TIME THE AMPLITUDE OF THE STAIRCASE REFERENCE SIGNAL CHANGES BY ONE STEP, MEANS FOR GENERATING A SAWTOOTH VOLTAGE EACH TIME THE REFERENCE SIGNAL AND THE STROBE SIGNAL IS SAMPLED, SAID SAWTOOTH VOLTAGE BEING APPLIED TO THE SECOND SWEEP CIRCUIT, A STROBE DISPLAY GATE GENERATOR RESPONSIVE TO SAID SAWTOOTH VOLTAGES FOR GENERATING A STROBE DISPLAY GATE AT A SELECTED TIME DURING THE GENERATION OF THE SAWTOOTH VOLTAGES, MEANS RESPONSIVE TO THE SYNCHRONIZING SIGNAL FOR GENERATING A STROBE TIME SHARING GATE DURING A STROBE DISPLAY PORTION OF THE PERIOD OVER WHICH THE STAIRCASE REFERENCE SIGNAL IS SUBSTANTIALLY CONSTANT, A STROBE GATE COMPARISON CIRCUIT RESPONSIVE TO SAID STROBE DISPLAY GATE FOR PASSING SAID STROBE DISPLAY GATE, A PLURALITY OF SCHEDULE DISPLAY GATE GENERATORS FOR PRODUCING A PLURALITY OF DISPLAY GATES AT SELECTED AND DIFFERENT SCHEDULE DISPLAY TIMES IN RESPONSE TO SAID SAWTOOTH VOLTAGE,