The possibility of using nonlinear effects in hydroacoustic systems with parametric radiation mode for profiling the bottom and bottom sediments attracts the attention of both domestic and foreign specialists. The use of parametric antennas in hydroacoustic equipment allows, due to their high directivity and low side field level, to increase the information content and accuracy in detecting and determining the coordinates of underwater objects, and to obtain additional features for recognition. The efficiency of using a parametric profiler for solving problems that require high resolution is justified. A block diagram of a parametric profiler for studying the layered structure is developed. The features of the signal generator and the amplification unit are considered. The characteristics of the radiating antenna were measured under laboratory conditions. It is shown that the directivity characteristic is constant in the operating frequency range and the acoustic power at the output makes it possible to solve the tasks of sounding up to 10 m into the ground. A record of the soil profile was obtained, confirming the operability of the system. In the future, the results will be used in full-scale conditions with the use of cepstral echo processing.

Keywords: profilograph, parametric antenna, kepstr, block diagram, signal generator, power amplifier, directional pattern, amplitude-frequency response, pump antenna, ground profile

The use of a separate receiving antenna at different frequencies in parametric acoustic systems is associated with the irreversibility of nonlinear processes underlying its principle of operation. The paper considers the results of experimental and theoretical studies to assess the influence of external elements on the amplitude-frequency response of a piezoceramic acoustic antenna. The structural scheme of the experimental setup is considered. It is shown that parallel connection of an external inductance to a piezoelectric element allows shifting the antiresonance frequency of an acoustic antenna, which leads to an increase in both the signal amplitude at the antenna output and an increase in the complex resistance module at the operating frequency.

Keywords: acoustic antenna, the sensitivity of the receiving antenna, the amplitude-frequency characteristic, the modulus of the complex resistance

The paper deals with the theoretical substantiation of the directional properties of the antenna arrays of a parametric profilograph intended for installation on an underwater uninhabited apparatus. A feature of such systems is the structural limitations of the overall dimensions of the carrier, which do not allow the antenna system to be implemented on the principles of linear hydroacoustics in the radiation mode. To solve this problem, we simulated the directional properties of the antenna arrays of the pump converter of a parametric profilograph. The directivity characteristics calculated for the center frequency of pumping in the diametral and traverse planes make it possible to take into account the expansion of the directivity of the radiating antenna when compensating for specified angles. The obtained values ​​of the estimation of the change in the directivity characteristic by the level of 0,7 make it possible to ensure the necessary axial concentration ratio of the radiating antenna of the profilograph for each of the working frequencies.

Keywords: parametric profilograph, bottom survey, pumping antenna, directional characteristic, scanning, side-lobe level

The paper deals with the optimization of characteristics and justification of the directional properties of the receiving antenna of a parametric profilograph. A feature of such systems is their performance in the form of a separate receiving channel, providing high sensitivity, the possibility of matching with the receiving-amplifier path and the best signal-to-noise ratio. In addition, the receiving antenna must provide for the required overall limitations the required angular resolution in the entire sector of the review. In solving these problems, the simulation was performed on the directional properties of the antenna receiving antenna. The issues of optimizing the layout of the antenna system and the use of cylinders on the transverse piezoelectric effect as elements of the receiving antenna are considered. The question of eliminating the influence of the thickness of the fill of the receiving antenna on the transparency coefficient is considered, which allows to ensure the necessary sensitivity of the receiving antenna.

Keywords: Kirichenko I. A.

Within the framework of solving the problem of increasing the effectiveness of the directional properties of adaptive systems with parametric sonar emitting antenna in the results of generalization of theoretical and experimental studies of the effect of hydro-irregularities on the characteristic parameter of the antenna. A comparison of the results of calculations of the antenna directivity characteristic parameter derived from the model Khokhlova-Zabolotskaya-Kuznetsova, with the results of experimental measurements of the directional properties of the parametric array. We obtain the normalized dependence of the width of the parametric characteristics of the antenna by lowering the difference frequency from the center frequency of the pump waves of 5 to 16 times. The influence of changes in the speed of sound in the direction of the parametric array. We obtain the normalized dependence of the width of the antenna characteristics of the parametric values of the sound velocity at the surface of the pump transducer. It was found that the greatest impact on the characteristic parameter of the antenna has a change in the speed of sound to a distance equal to the lengths of 1-2 zone diffraction of the pump waves.

Keywords: adaptive sonar system, efficiency, parametric antenna, directivity characteristic

The paper presents the results of theoretical studies of the problem assess the impact of structural features in the design phase in the direction of the acoustic antennas. Consider the generalized algorithm of forming directional characteristics of a special form in the application hydroacoustic problems and solutions of the generalized problem of optimizing the characteristics of antennas and modular design principle. Optimization problem proposed to divide into separate components: optimization of antenna characteristics and optimization of tactical performance speaker system that comprehensively affect the choice of antenna design. The method of constructing an antenna with a pie chart in the horizontal plane when the parametric antenna sector review contains some highly directional converters pumping flat aperture.

Keywords: acoustic antenna, directivity characteristic, sector

Application for monitoring ice conditions devices based on nonlinear acoustics using parametric radiating antenna takes into consideration such characteristics of the formation of the acoustic field, as having both low-frequency difference frequency formed as a result of the nonlinear interaction of two close by the value of the pump waves, and, in fact, high-frequency radiation source pump waves Development of instruments for acoustic monitoring ice conditions require consideration of all possible real oceanographic situations in which they will operate. The article discusses the results of the development of a system for monitoring the panorama of ice conditions in the parametric mode sonar. The analysis of the formation and propagation of the probing signals into acoustic channel parametric meter ice thickness is formulated the principle of measuring the thickness of the reflection (scattering) of the acoustic signals from a locally stratified system with blurred boundaries. Mathematical modeling of the acoustic channel power meter ice thickness and "windows of transparency" on the basis of the calculation of the critical angles of incidence and refraction. The conclusion of the feasibility of using as reference signals of shear waves.

Keywords: ice monitoring acoustic antenna, the critical angle , the transparency window

A model system was designed and test  trials of physical and mechanical characteristics of small – crystalline and granular flotation potassium chloride are studied. This model system allows to design storage and transportation  of fertilizers in bulk in railway wagons and it has the same static and vibrational load as real system. The effect of temperature and relative humidity of the air on hygroscopy of small – crystalline and granular КСl were studied. Furthermore the influence of static load, and time length  of compression process of fertilizing layer and parameters of static and vibrational load on composition of КСl granules were investigated. It was experimentally proved that the humidity increase (0,5 %) of granular КСl and the  increase of static load and time length  of compression process of product during transportation in bulk lead to increase of compaction degree and caking ability of product. Research of the influence of high static load (10-30 kg/sm2) and time length of compression process of fertilizing layer on caking ability and degree of compaction show that small – grained KCl has smaller degree of compaction and considerably higher value of caking ability in comparison with granular KCl.

Keywords: Potash fertilizers, storage and transportation, hygroscopy, caking ability, degree of compaction, commodity characteristics of fertilizers

Acoustic system parameters were selected and calculated: wave modes used when controlling, wave entry and frequency angles according to kind of decay process and ultrasonic attenuation. Control procedure was developed

Keywords: ultrozvuk, frequency, attenuation process, technology, acoustic system

This paper shows the results of the experimental research the passage of the ultrasonic beam through modifiable layered structure in order to obtain data on changes in levels of pressure in the front slice of the acoustic field. This paper presents the spatial distribution characteristics of the acoustic field after passing the various layers in the liquid. Celebrated not only offset the propagation path, but also change the chart pressure in the front slice on the amplitude level , the width of the chart, the position of the lateral lobe and its amplitude.

Keywords: Ultrasound, layered medium, experimental assembly, refraction.

Operation of sylvinite ore desliming is an important step of potassium chloride production by floatation method. It is known that ultrasonic treatment is applied to increase the efficiency of insoluble rest separating from an ore. The purpose was to establish kinetic regularities of the insoluble rest removal from sylvinite ore crystals of the same particle size distribution. Investigations were carried out with mechanical stirring and sonication of varying intensity. It is established that process of sylvinite ore desliming occurs in the diffusion mode. Application of ultrasonic treatment allows to intensify process in 2-4 times as compared with mechanical desliming. Influence of sylvinite ore treatment parameters to chemical composition changing of the insoluble rest is defined. It is shown that sonication for 90 seconds leads to removing carbonates from ore crystals withal concentrating of the iron compounds.

Keywords: desliming, sylvinite ore, ultrasonic treatment, sonication, insoluble rest.

We study the problems in the propagation of acoustic waves of a sound range near the boundaries of media. The features of the wave processes occurring at the water-air interface, due to the influence of inhomogeneous waves. Considered in detail the properties and parameters of an inhomogeneous plane wave. The mathematical calculations of the transmission coefficients L.M. Brekhovskikh for spherical and cylindrical waves through this boundary, allowing to take into account the contribution of inhomogeneous components. It is shown that than the frequency of radiation of a source is lower and the closer it is located to water-air interface, the acoustic transparency of this border is higher. Study of the dependence of the transmission coefficient of the water-air interface at low frequencies can have important consequences in a number of fundamental and applied problems. Increase the transparency of the interface requires a reassessment of the feasibility of acoustic communication from water in the air, the detection of underwater sources without dipping into the water and acoustic monitoring of the physical processes occurring in the water.

Keywords: Inhomogeneous plane wave, water-air interface, transmission coefficient, wavelength, spherical wave, acoustic impedance.

A hybrid reverberation algorithm is offered in this article. This algorithm is using both a convolution section in which a convolution with an inmpulse response of a real acoustic room is being implied and a mathematical reverb model. Also an algorithm for generating impulse responses of optional rooms is also offered in the following article. The algorithm efficiency calculation is  specified in the article. Thia reverberation algorithm is a part of a bigger complez auralization algorithm where it is being used coherently with an HRTF-based algorithm in order to simulate a real acoustic environment  

Keywords: artificial reverb, room simulation, convolution algorithm, impulse response convolution, impulse response synthesis, dynamic convolution, complex filtering

Solution for high-speed video transmission in hydroacoustic channel by amplitude modulation with orthogonal subcarriers is specified. Results of method experimental check are presented. Discussed method is doppler-tolerant and can be realized in many common DSPs.

Keywords: hydroacousitcs, video transmission, amplitude modulation

Consideration of the formation method of choice underlying architecture of reconfigurable computing system minimal cost, providing the requirements for the probability of the task. The main mathematical tool used in the theory of decision making under uncertainty, as well as methods for game-theoretic optimization.

Keywords: reconfigurable computing system, Markov processes, game-theoretic optimization, basic architecture, the uncertainties