Ultra Low Frequency Fields of Moving Bodies

ISBN: 9781536126105 出版年：2017 页码：269 Andrey Grigorievitch Semenov Nova Science

A new approach to body detection and control based on its unavoidable ultra-low frequency (ULF) oscillation related to its motion in media (mainly, in the ocean) is presented. The main concept of this approach lies in enriching the list of moving body control enabling factors by influence of ULF oscillations on the body’s outer fields. It is shown that ULF oscillation of a moving body could be detected in the atmosphere or in the ocean directly with the aid of ambient fluid ULF pressure or velocity changes, say, observed inside an oceanic layer or on the ocean’s surface. But ULF oscillation’s indirect appearance is demonstrated to be the most important for submerged moving body detection. This appearance comprises an additional ULF modulation (distortion) of outer natural sound fields related to ocean wind noise and distant shipment noise in forward scattering. The physical analogy an indirect moving body ULF oscillation is justified in the book and could be partly compared to the recent universe gravity waves detection discovery in 2016 with the aid of electromagnetic wave distortion that is provided by gravity wave propagation. Specifics of sound scattering by flow inhomogeneity generated by a moving body were demonstrated in Acoustics of Moving Inhomogeneities, which was published recently by Nova Science Publishers. However, this very book is devoted in particular to the modulation of forward scattered sound fields of the ULF field provided by a moving body and the application of corresponding results to its control in the ocean, as well as mainly to submerged submarine control. Proposed detection methods are independent of a moving body’s self-noise level. Their application requires consideration of the ambient flow (including surface gravity wave flows) contribution to sound diffraction by the finite size moving body, mainly in forward scattering. A lot of known diffraction problem results should be revised in the light of a moving body ULF field. Examples of practical applications are presented, showing that moving body detection (especially in deep water ocean regions with the aid of natural outer field ULF modulation) is successfully achieved. Detection in shallow water regions is slightly worse due to a smaller wave inhomogeneity scale and when the natural ULF hydrodynamics’ noise field level increased. It is shown that body detection distances being thought as unachievable are realized in light of these new moving body ULF field effects. The book is aimed at providing a new approach to external fields of a moving body, mainly submarines. This version of submarine detection is practically substantiated and proven to be effective in Russia for various ocean regions with the aid of various types of arrays. Conclusions substantiated in the book are recommended for practical application. At the same time, additional efforts of scientists, hydroacoustics and naval equipment specialists related to various ULF field applications based on theory predictions are necessary.