Method of and apparatus for locating predetermined portions of a radio-frequency pulse, particularly adapted for leading edge location of loran and similar navigational pulses

摘要: This disclosure is concerned with locating the leading edge of radio-frequency pulses, such as ground-wave Loran transmissions, by sampling received signal information backwardly until no present, then forwardly in narrower time intervals reappears, and forward-sampling to lock on a predetermined cycle.