Range measuring system

Claim 1

A MISS-DISTANCE MEASURING SYSTEM FOR INDICATING THE MINIMUM DISTANCE BETWEEN TWO MOVING STATIONS, ONE OF WHICH IS A MISSILE AND THE OTHER OF WHICH IS A TARGET, THE SYSTEM COMPRISING, AT ONE STATION, A TRANSPONDER FOR RECEIVING MODULATED SIGNALS AT A FIRST CARRIER FREQUENCY AND TRANSMITTING THEM AT A SECOND FREQUENCY, AND AT THE OTHER MOVING STATION, MEANS FOR GENERATING PULSES AT A CONTROLLABLE REPETITION RATE VARIABLE OVER A PREDETERMINED RANGE, A TRANSMITTER HAVING A CARRIER AT SAID FIRST CARRIER FREQUENCY AND MODULATED BY THE OUTPUT OF THE PULSE GENERATING MEANS, A RECEIVER FOR DEMODULATING SIGNALS RECEIVED AT SAID SECOND CARRIER FREQUENCY, DELAY MEANS COUPLED TO THE OUTPUT OF THE RECEIVER FOR DELAYING THE RECEIVED PULSES BY A PREDETERMINED AMOUNT, A PHASE SENSITIVE DEVICE FOR GENERATING AN OUTPUT SIGNAL INDICATIVE OF THE PHASE RELATION BETWEEN TWO INPUT PULSE TRAINS, SAID PHASE SENSITIVE DEVICE BEING COUPLED TO THE OUTPUT OF THE PULSE GENERATING MEANS AND THE OUTPUT OF THE DELAY MEANS FOR PRODUCING A CONTROL SIGNAL IN RESPONSE TO VARIATIONS IN THE PHASE RELATIONSHIP OF THE TRANSMITTED AND RECEIVED PULSES, AND MEANS FOR CONTROLLING THE PULSE REPETITION RATE OF THE PULSE GENERATING MEANS IN RESPONSE TO THE CONTROL SIGNAL FROM THE PHASE SENSITIVE DEVICE, WHEREBY THE PULSE REPETITION RATE OF THE PULSE GENERATING MEANS IS VARIED IN PROPORTION TO CHANGES IN THE TOTAL PHASE RELATION BETWEEN THE TWO PULSE TRAIN SIGNALS APPLIED TO THE PHASE SENSITIVE DEVICE.