Altitude correction techniques

Claim 1

IN AN AIRCRAFT RADAR SYSTEM FOR PRODUCING CATHODE RAY TUBE REPRESENTATIONS OF GROUND RANGE, AN ALTITUDE CORRECTION CIRCUIT COMPRISING: AN INPUT FOR APPLYING RAMP FUNCTION VOLTAGE SIGNALS HAVING DWELL PERIODS THEREBETWEEN FOR DRIVING THE DEFLECTION CIRCUITS OF A CATHODE RAY TUBE OF SAID SYSTEM TO DISPLAY RANGE OF A GROUND AREA; A RADAR SYNCHRONIZING PULSE INPUT; A RADAR NULL PULSE INPUT; A FIRST SAMPLING AND SWITCHING MEANS COUPLED TO SAID RAMP FUNCTION VOLTAGE SIGNAL INPUT AND TO SAID RADAR SYNCHRONIZING PULSE INPUT TO PRODUCE A DIRECT CURRENT VOLTAGE PROPORTIONAL TO THE VOLTAGE OF SAID DWELL PERIODS OF SAID RAMP FUNCTION VOLTAGE SIGNALS ON AN OUTPUT THEREOF; A SECOND SAMPLING AND SWITCHING MEANS COUPLED TO SAID FIRST SAMPLING AND SWITCHING MEANS AND TO SAID RADAR SYNCHRONIZING AND NULL PULSE INPUTS AND RESPONSIVE TO A PREDETERMINED VOLTAGE LEVEL OF EACH RAMP FUNCTION VOLTAGE SIGNAL PRODUCED BY SYNCHRONIZED PULSES TO PRODUCE CORRESPONDING EXPONENTIALLY VARYING VOLTAGE PULSES, EACH TERMINATING WITH THE APPLICATION OF A NULL PULSE, SAID EXPONENTIALLY VARYING VOLTAGE PULSES BEING OVER AN OUTPUT OF SAID SECOND SAMPLING AND SWITCHING CIRCUIT; AND AN ADJUSTABLE MEANS TO ADJUST VOLTAGE CONDUCTION THERETHROUGH REPRESENTATIVE OF THE ALTITUDE OF THE AIRCRAFT RADAR SYSTEM TO CORRECT FOR GROUND RANGE AT THAT ALTITUDE, SAID ADJUSTABLE MEANS BEING COUPLED TO THE OUTPUTS OF SAID FIRST AND SECOND SAMPLING AND SWITCHING CIRCUITS TO ADJUSTABLY CONTROL THE DIRECT CURRENT AND EXPONENTIAL VARYING VOLTAGES THEREOF WHEREBY THE RAMP FUNCTION VOLTAGE SIGNALS ARE CORRECTED IN RAMP FUNCTION FOR THE DEFLECTION CIRCUITS OF A CATHODE RAY TUBE RADAR RANGE DISPLAY TO PRESENT GROUND RANGE DISPLAY.