SIGNAL PROCESSING SYSTEM FOR EXTRACTING A PERIODIC SIGNAL OF UNKNOWN FREQUENCY FROM A HIGH LEVEL BACKGROUND NOISE

摘要

A detector identifies the frequency of a periodic signal buried beneath the threshold of background noise. A correlator compares the frequency of the output of a sweep generator with the incoming signal. When the correlator indicates that the frequency of the sweep generator output coincides with that of the periodic signal, a recording is made of the sweep generator output.