Radar systems

Claim 1

A RADAR SYSTEM SUITABLE FOR MARINE USE AND COMPRISING MEANS FOR DERIVING, AT A PREDETERMINED LOW PERIODICITY, A SUCCESSION OF SETS OF INFORMATION, EACH SET BEING OF INFORMATION AS TO THE DIRECTION AND DISTANCE OF RADIO REFLECTING TARGETS WITHIN THE RANGE OF THE SYSTEM; A PLURALITY OF INFORMATION STORAGE MEANS; MEANS FOR CYCLICALLY STORING A SEQUENCE OF SAID DERIVED SETS IN SAID INFORMATION STORAGE MEANS WITH A DIFFERENT SEQUENTIAL SET STORED IN EACH STORAGE MEANS; MEANS FOR TAKING OFF, AT A RELATIVELY HIGH CYCLIC SPEED OF REPETITION WHICH IS HIGH RELATIVE TO THE FIRST-MENTIONED LOW PERIODICITY, THE SETS OF INFORMATION STORED AT ANY GIVEN TIME IN SAID INFORMATION STORAGE MEANS; SIGNAL STORING MEANS FOR STORING, DURING THE DERIVING OF THE SUCCESSION OF SETS OF INFORMATION, SIGNALS REPRESENTATIVE OF THE AMOUNT AND DIRECTION OF MOVEMENT OF THE RADAR SYSTEM AS A WHOLE DURING THE TIME TAKEN TO DERIVE SAID SUCCESSION OF SETS, MEANS FOR UTILIZING THE SETS OF INFORMATION TAKEN OFF TO PRODUCE A FINAL DISPLAY OF THE P.P.I. TYPE, AND FURTHER MEANS FOR UTILIZING THE STORED MOVEMENT REPRESENTING SIGNALS TO DEFLECT THE ORIGIN OF THE P.P.I. DISPLAY OF EACH SET OF INFORMATION IN SAID DISPLAY ON THE SURFACE ON WHICH SAID FINAL DISPLAY IS PRODUCED BY AN AMOUNT REPRESENTATIVE OF THE AMOUNT OF AND IN A DIRECTION OPPOSITE TO THE DIRECTION OF SAID MOVEMENT OF THE RADAR SYSTEM AS A WHOLE DURING THE TIME ELAPSING BETWEEN THE DERIVING OF THE SET IN QUESTION AND THE DERIVING OF THE LAST SET TO BE DERIVED SO THAT THE FINAL DISPLAY IS A TRUE MOTION DISPLAY IN WHICH THE LAST POSITION, AT ANY TIME, OF THE RADAR SYSTEM AS AS WHOLE IS ALWAYS LOCATED AT A PREDETERMINED POSITION ON THE SURFACE ON WHICH THE FINAL DISPLAY IS PRODUCED.