RU2012114282A - METHOD FOR EVALUATING THE GEOLOGICAL STRUCTURE OF UPPER BOTTOM LAYERS - Google Patents

Abstract

1. A method of evaluating the geological structure of the upper layers of the bottom by measuring the propagation parameters of low-frequency acoustic signals in the marine environment associated with the emission and reception of acoustic harmonic vibrations in the aquatic environment, characterized in that, in order to obtain data on the geological structure of bottom sediments and their parameters, produce radiation of an acoustic signal into the aqueous medium and its reception at a certain horizontal distance from the source, which constantly varies uniformly in time along the line connecting horizontally the source and the receiver so that the receiver constantly records the changing interference structure of the wave field in the medium, according to which, using known algorithms, the parameters of normal waves of the acoustic field, such as the phase propagation velocity, amplitude and attenuation, are extracted, and then the wave equation with boundary conditions is solved, setting in the form of a boundary the parameters of several layers lying on each other, such as the layer thickness, its density, propagation velocity and sound attenuation, the calculation results in ide parameters normal waves are compared with the data of the experimental results is constantly changing parameters of layers in the calculations, the parameters of the geological structure of the upper bottom sediments obtained when the best match with the experimental data the calculations rezultatami.2. The method for assessing the geological structure of the upper layers of the bottom according to claim 1, characterized in that the distance between the emitter and the receiver changes either when the emitter is towed at a uniform speed with a stationary receiver, or the receiver is towed

Claims (4)

1. A method for assessing the geological structure of the upper layers of the bottom by measuring the propagation parameters of low-frequency acoustic signals in the marine environment associated with the emission and reception of acoustic harmonic vibrations in the aquatic environment, characterized in that, in order to obtain data on the geological structure of bottom sediments and their parameters, produce radiation of an acoustic signal into the aqueous medium and its reception at a certain horizontal distance from the source, which constantly varies uniformly in time along the line connecting horizontally the source and the receiver so that the receiver constantly records the changing interference structure of the wave field in the medium, according to which, using known algorithms, the parameters of normal waves of the acoustic field, such as the phase propagation velocity, amplitude and attenuation, are extracted, and then the wave equation with boundary conditions is solved, setting in the form of a boundary the parameters of several layers lying on each other, such as the layer thickness, its density, propagation velocity and sound attenuation, the calculation results in ide parameters normal waves are compared with the data of the experimental results is constantly changing parameters of layers in the calculations, the parameters of the geological structure of the upper bottom sediments obtained in the best coincidence of data calculations and experimental results. 2. The method for assessing the geological structure of the upper layers of the bottom according to claim 1, characterized in that the distance between the emitter and the receiver changes either when the emitter is towed at a uniform speed with a fixed receiver, or the receiver is towed with a fixed emitter, and the towing distance should be greater $$\Delta r>\frac{\mathrm{one}}{f}\cdot \frac{C_g\cdot C_{\mathrm{at}}}{C_g-C_{\mathrm{at}}}$$

, where f is the radiation frequency, C _g is the largest estimated velocity of sound propagation in the bottom soil, C _in is the speed of signal propagation in water. 3. The method of assessing the geological structure of the upper layers of the bottom according to claim 1, characterized in that the data on the parameters of normal waves are obtained not by changing the horizontal distance between the sound source and the receiver, but by moving the receiver in a vertical plane to the entire thickness of the water surface. 4. The method for assessing the geological structure of the upper layers of the bottom according to claim 1, characterized in that to ensure the separation of normal waves, the phase difference of the emitted and received signal is measured during the movement of the emitter or receiver, for which the signals during radiation and during reception are recorded on an electronic carrier in a single time with a relative error is much less than the duration of the period of the emitted signal.