Real time dereverberation and signal processing of marine seismic reflection profiles

A real time dereverberator was tested in an attempt to eliminate multiples on marine reflection seismograms. The whole system consists of a4 \times 30-m sectional array, a slacking winch used to stop the array during the recording period, a 1000-in³airgun with a pulse shaper, four programmed gain amplifiers, a time varying mixer, a time varying bandpass filter and a real-time correlator and dereverberation filter. A peak pressure noise figure of less than 1\mubar in the frequency band of 16 to 60 Hz is attained with the system. Record comparisons are presented to show the advantages of the various components of the system. Dereverberated records expose real events which are otherwise masked by multiples.