2014, volume 7, issue 1

Actual problems of the theory of surface waves, tides, interactions between waves and barriers ‎and also the development of hydroacoustic detectors are considered. The numerical scheme ‎based on non-orthogonal curvilinear coordinate system is developed for modeling of three-‎dimensional potential waves. The results of experimental and theoretical (numerical) researches of ‎the interaction between waves and short vertical walls have been analysed. On the basis of ‎modeling of surface semidiurnal tide the energetic characteristics in the Canadian Arctic ‎Archipelago including the system of Hudson Bay are estimated. Data of calculations of the ‎hydrodynamic forces developed by a wing at any phase shift between linear and angular ‎fluctuations of a flat rigid wing are provided. The possibility of use of the principles of an ‎adaptive filtration at realization of the interferential detector of moving underwater objects is ‎discussed. The effective time-domain adaptive noise canceller is offered.‎


2014, volume 7, issue 2

The issue presents the materials of round-table discussion «Fundamental ‎Science to The Navy» which was held within the International Maritime Defence ‎Show in 2013 (IMDS-2013). The directions of fundamental, expected and pilot ‎researches, the development of the latest technologies provided by them are ‎discussed. The innovative potential for development of arms and technical means ‎of the Navy and the directions of realization of military-technical policy of the State ‎are considered. Series of articles showing modern researches in hydroacoustics is ‎presented. The new abilities for long range ocean monitoring arising with underwater ‎parametric array application are discussed. The advanced methods and algorithms ‎of digital space-time signal processing in multi-channel sonar systems for monitoring ‎the underwater situation in sonar complexes of various purposes are considered. ‎The evaluations of energy transmission rates of hydroacoustic information and ‎control networks are shown. The practical recommendations to produce remote ‎control system for underwater vehicle and its navigation are given.‎


2014, volume 7, issue 3

The issue presents review and analysis of few-parameter optical models of ‎seawater inherent optical properties; correlational and structural models are ‎considered, their possibilities, disadvantages and range of application are ‎shown. The estimation of the geostrophic water transport by the Antarctic ‎Circumpolar Current through the Drake Passage in December 2003 on the basis ‎of full-size measurements is given. The results of satellite and field observations ‎are discussed to study submesoscale dynamical processes and phenomena in ‎the White Sea associated with internal waves, eddies and frontal features. The ‎onset mechanism of self-oscillations of mast hoisting gears related to their non-‎linear hydrodynamic characteristics as well as the action of external periodic ‎forces on this self-oscillating system caused by the vortex separation is ‎considered; mast hoisting gear amplitude-frequency characteristics in the ‎resonant area are plotted. The methods of design technique and future proof ‎scheme of the ship pipe anti-noise tool is discussed; the new method of ‎pressure pulsation dampener design is presented. The features of practical ‎implementation of the holographic method of the acoustic field recovery and ‎visualization of the sound source in the space of the waveguide, which is the ‎method of the matched field processing, as well as the theoretical basis of the ‎method are considered. The results of computational experiments on the study ‎of the effectiveness of the method in the conditions of an inhomogeneous ‎underwater environment are given.‎


2014, volume 7, issue 4

The issue presents papers about theoretical and experimental investigations of ‎surface and internal waves, hydroacoustic and marine optics subjects are consid-‎ered. Based on numerical solving of stationary one-dimensional potential equa-‎tions in conformal coordinates the main properties of Stokes waves for the case ‎of optional depth are analyzed. The derivation of the fifth-order Korteweg—‎de Vries equation is presented for internal waves in two-layer fluid with surface ‎tension on the interface between the layers. The results of level rise simulation in ‎the Gulf of Finland during the passage of the extreme and really observed cy-‎clones over the Baltic Sea taking into account the operation of St.-Petersburg ‎Flood Protection Barrier are discussed. Characteristic features of lidar images of ‎nonlinear internal waves are calculated and analyzed using actual profiles of hy-‎drooptical and hydrologic data obtained in the Barents Sea at the presence or ‎absence of current in upper layer. A new method for determining the wave spec-‎trum based on the distribution of number and sizes of the Sun glints on the rough ‎sea surface is proposed. On the basis of review of ice, snow and oil optical prop-‎erties the analysis of the possibility of detecting oil pollution on the lower ‎ice/water boundary is presented. A method of modeling of signals of compo-‎nents of the velocity vector sensor that is placed in the stream consisting of ‎whirls with different sizes and oriented along and across the flow is suggested. ‎The results of syntheses of optimal maximum likelihood automatic target recog-‎nition algorithm based on amplitude modulation of their signals are shown.‎