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The Role of Nonlinear Hydroacoustics in Marine Technologies of the Sea Shelf Research and Development
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, Marine Technologies 2019, Apr 2019, Volume 2019, p.1 - 5
Abstract
The main feature of parametric sonars, the principle of which is based on the nonlinear interaction of acoustic waves, is the constancy of the beam pattern in a wide low-frequency frequency range. The General principal advantage of parametric narrow-beam profilers is that at the same volume of the medium within a narrow beam, at all frequencies, is "voiced", which allows comparing the results of measurements at different frequencies. Two types of parametric profilers are presented for the survey of the structure of the sedimentary layer of the seabed. This is a low-frequency parametric seismic Profiler operating in the range of difference frequencies from 0.5 to 5 kHz at an average pump frequency of 30 kHz. Depending on the type of bottom soil, the depth of penetration can reach 500 meters. The second device is an original equipment, the so-called parametric side-scan sonar. Its main technical characteristics: the range of difference frequencies is 7–20 kHz, with an average pumping frequency of 145 kHz. The depth of penetration, depending on the type of soil, is 50 meters with a resolution of 10 cm when using the LFM signal. The use of parametric profilers with complex signals makes it possible to study the structure of the upper part of the sedimentary cover with high accuracy and to evaluate the physical properties of marine sediments.