Rapid synchronous time interval detector

Claim 1

IN A RANGING SYSTEM, A DETECTOR FOR USE WITH A RECEIVER FOR LOCATING A SYNCHRONOUS RETURN PULSE PROPAGATED FROM A CORRESPONDING BEACON AND RECEIVED BY THE RECEIVER FROM AMONG A NUMBER OF NON-SYNCHRONOUS PULSES RECEIVED BY THE RECEIVER COMPRISING: A SOURCE OF TIMING PULSES; MEANS COUPLED TO SAID SOURCE FOR GENERATING INTERROGATION PULSES; MEANS FOR BLOCKING RECEPTION OF THE RETURN PULSE FOR A PRESET TIME INTERVAL AFTER THE GENERATION OF EACH OF SAID INTERROGATION PULSES; MEANS FOR MEASURING THE TIME INTERVAL BETWEEN THE GENERATION OF EACH OF SAID INTERROGATION PULSES AND THE RECEPTION OF THE FIRST RETURN PULSE AFTER THE EXPIRATION OF SAID BLOCKING TIME INTERVAL; MEANS COUPLED TO SAID SOURCE OF TIMING PULSES AND SAID MEASURING MEANS FOR PROVIDING AN OUTPUT TRAIN OF PULSES INDICATIVE OF SAID MEASURED TIME INTERVAL; AND MEANS CONNECTING SAID MEASURING MEANS TO SAID BLOCKING MEANS FOR SUPPLYING SAID OUTPUT TRAIN OF PULSES