FREMGANGSMAATE OG INNRETNING FOR FREMBRINGELSE AV ET SEISMISK SIGNAL.

摘要

A method and system for producing a seismic signal indicative of the substrata beneath a body of water comprising the steps of: supplying acoustic energy to the body of water; sensing both the pressure waves and the motion of the water particles accompanying pressure waves reflected from the substrata below the water and from the surface of the water; normalizing the amplitudes of the pressure wave and particle motion signals; modifying the phase shifts of these pressure wave and particle motion signals so that each of the phase shifts of such signals, other than phase shifts caused by the time at which the pressure waves and particle motions are sensed is zero; modifying the amplitude of each frequency component of the normalized, zero-phased signals as a function of the signal-to-noise ratios related to the pressure wave and particle motion sensing steps; and combining these modified signals to reduce or eliminate the effect of the surface reflection on the recorded seismic signal.