Method for attenuation of reverberations using a pressure-velocity bottom cable. Three successive rebounds within the water layer, if not more, are visible and can be readily accounted for. The method of wave-equation datuming introduced by Berryhill , propagates extrapolates upgoing wavefields backward and downgoing wavefields forward in space and time. These events must be eliminated from the recorded section in order to allow a better understanding of the geology of the area. At step 47 , a reflection coefficient R at the water bottom datum is determined.
The flows that have been visited by submersibles are often a combination of two or more of the above. Determination of reflectivity and water depth for firing marine sources as an inverse distortion operator. Hence the partition coefficient measures how hydrophilic or hydrophobic a chemical substance is. In contrast, the time window used for the prior art first arrival method employed a time window in the range of 20 to milliseconds, depending on water depth. Guenther [GUE 85] proposed to estimate L s based on an empirical parameterization derived from wind speed and direction. These solutions can be computed in the Fourier domain by simple division. The survey ship 12 fires the source 14 at predetermined locations while the signals from the hydrophone and geophone arrays are recorded.
water bottom - an overview | ScienceDirect Topics
Now consider energy which crosses the water bottom and returns to the water layer from below after reflecting once from interface However, when the length of the multiple reflection path becomes long compared to the source wavelet duration, the multiples are no longer periodic and predictive deconvolution no longer works well. These are about 5 to about 15 million years old, that is, they originated in the Pliocene or Miocene. They are visible laterally away from the object. Typically, the amplitude and phase of the geophone data are corrected to match the hydrophone data.
Several populations, however, have been destroyed or severely diminished by dam construction, earth fill, or pollution. However, the type of sensors , or their location in the seismic streamers is not intended to be a limitation on the present invention. Therefore, cylindrical, gimbal geophones are attached to the bottom-cable. Conversely, the pineal gland, which in amphibians controls circadian rhythms, gamete development, and pigmentation changes, is greatly reduced. The gathers are then transformed into the Radon space which is frequency-space, f-x domain where the data is decomposed into a series of parabolas, with the energy in each parabola being mapped to a P or moveout trace. The method of claim 1 , wherein the step of subtracting to generate an up-going wavefield w b t us at the water bottom substantially without water bottom multiples comprises applying the equation: However, the peg-leg multiples are not completely eliminated but are transformed into a simple scaled reverberation sequence.