Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Hydroacoustics" wg kryterium: Temat

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-45 z 45
    Tytuł:
    Hydroacoustics waves direct-of-arrival estimation using music algorithm - simulations results
    Autorzy:
    Żak, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/332842.pdf
    Data publikacji:
    2009
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    music algorithm
    hydroacoustics waves
    hydroacoustics
    Opis:
    Paper presents simulations results of hydroacoustics waves' direction-of-arrival estimation using MUSIC algorithm. Firstly, the research problem is formulated by general description of studied case and release of simplifying assumption. Next the used to direct-of-arrival estimation MUSIC algorithm was discussed. The mathematical formulations, algorithm of calculation and some computational issues were presented. At the end of the paper the simulations results of estimation of direction-of-arrival using MUSIC algorithm for hypothetical situation were presented.
    Źródło:
    Hydroacoustics; 2009, 12; 249-256
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The examination of position of ships noises sources based on hydroacoustics method
    Autorzy:
    Listewnik, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/331584.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    hydroacoustics method
    ship’s noises sources
    hydroacoustics
    Opis:
    The paper presents the experimental research associated with the transmission of acoustic energy generated by moving ship into the water. The paper present the methodology of evaluations acoustics energy from the mechanisms of ship into the water environment. For that purpose the research of noise distribution over ship's hull were conducted along with the hydroacoustic field. The hull is source of waves of complex surface shape inducing waves of different amplitudes and phases depending on the position of ship's machinery. As a result of the hull vibrations generated wave distribution depending on the primary sources, as the main propulsion units, generators or other mechanisms. This research allowed to determine position of the main noises' sources of acoustics energy of machinery and propulsion system depending on class of ships.
    Źródło:
    Hydroacoustics; 2008, 11; 247-253
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Contribution of the IMS global network of hydroacoustic stations for monitoring the CTBT
    Autorzy:
    Bitnner, P.
    Jonathan, E.
    Villarroel, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/331513.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    CTBT
    IMS
    hydroacoustics
    Opis:
    The International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) Preparatory Commission, in Vienna operates a global network of 321 monitoring stations and 16 radionuclide laboratories that monitors the earth for evidence of nuclear explosions within the atmosphere, underwater and underground. The IMS uses a network of four verification technologies: seismic, hydroacoustic, infrasound and radionuclide. All the data recorded by the IMS network are transmitted to the International Data Centre (IDC) of the CTBTO in Vienna. The data are then received, processed, resulting data and products distributed and archived by the IDC. This study will give an overview of the contribution of the IMS hydroacoustic network and will highlight that for areas not well covered with the seismic network this part of the IMS can be very valuable for detecting events, improving the location obtained from the seismic network and providing information about the nature of sources.
    Źródło:
    Hydroacoustics; 2008, 11; 19-26
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Investigation of the underwater noise produced by ships by means of intensity method
    Autorzy:
    Kozaczka, E.
    Domagalski, J.
    Gloza, I.
    Powiązania:
    https://bibliotekanauki.pl/articles/258726.pdf
    Data publikacji:
    2010
    Wydawca:
    Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
    Tematy:
    energy
    propagation
    hydroacoustics
    Opis:
    This paper presents results of research on spectral structure of underwater noise acoustic field radiated into water by selected ships moving in shallow waters. Underwater acoustic field of ships in motion is associated with acoustic activity of ship mechanisms and equipment under work. Vibration energy radiated by the mechanisms and devices is transmitted by ship structural elements to surrounding water where it is propagated in the form of acoustic waves of a wide frequency band. In this paper are presented results of the research on propagation of energy of acoustic waves in the near fiel, obtained from acoustic pressure measurements by means of two sensors located close to each other.
    Źródło:
    Polish Maritime Research; 2010, 3; 26-36
    1233-2585
    Pojawia się w:
    Polish Maritime Research
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Identification of hydroacoustic wave sources of ship in motion
    Autorzy:
    Kozaczka, E.
    Domagalski, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/259355.pdf
    Data publikacji:
    2010
    Wydawca:
    Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
    Tematy:
    identification
    propagation
    hydroacoustics
    Opis:
    This paper deals with results of identification tests of acoustic field spectrum of underwater noise generated by ship in motion. The field is connected with acoustic activity of ship mechanisms and devices in operation. Vibration energy generated by the mechanisms and devices is transferred through ship structural elements to surrounding water where it propagates in the form of acoustic waves of a broad band of frequencies. In the publication results of identification tests of underwater noise generated by a ship in motion, are presented.
    Źródło:
    Polish Maritime Research; 2010, 4; 64-71
    1233-2585
    Pojawia się w:
    Polish Maritime Research
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Identification of hydro-acoustic waves emitted from floating units during mooring tests
    Autorzy:
    Kozaczka, E.
    Domagalski, J.
    Grelowska, G.
    Gloza, I.
    Powiązania:
    https://bibliotekanauki.pl/articles/260463.pdf
    Data publikacji:
    2007
    Wydawca:
    Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
    Tematy:
    identification
    propagation
    hydroacoustics
    Opis:
    Measurements of hydro-acoustic noise emitted from vessels are a.o. a subject of the tests carried out in the control measurement ranges of the Navy. The measurements are performed both on anchored and floating vessels. Acoustic field of vessels is changing along with their speed changing and is associated with acoustic activity of wave sources installed in vessel’s hull (main engines, electric generating sets, reduction gears, pumps, shaft-lines, piping, ventilating ducts etc) as well as hydro-dynamic sources such as screw propellers and water flow around the hull [5, 7]. Vibration energy generated by the onboard devices is transferred through ship structural elements to water where it propagates in the form of hydro-acoustic waves of a wide frequency band.
    Źródło:
    Polish Maritime Research; 2007, 4; 40-46
    1233-2585
    Pojawia się w:
    Polish Maritime Research
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Theoretical problems of the wideband sonar time-spatial filtration
    Autorzy:
    Janowski, T.
    Kotłowski, A.
    Porosińska, E.
    Powiązania:
    https://bibliotekanauki.pl/articles/331819.pdf
    Data publikacji:
    2003
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    wideband sonar
    hydroacoustics
    Opis:
    The paper presents the synthesis of the time-spatial matched filtration algorithm. First part specifies base for the algorithm-input data. Successively, the matched filtration for continuous junction is depicted. This leads to the canonical form of the time-spatial filter. Consecutively, the decomposition into series connection of the matched and spatial filtration is realized. The next step is the signals approximation by Fourier series due to equivalence between approximation and interpolation on uniformly distributed discrete sampIes. The equation of the spatial filtration - in frequency domain - results from this mathematical operations. Application of the Bluestein's method to solve this equation provides to the final algorithm version. Advantages of the developed algorithm are presented in conclusions.
    Źródło:
    Hydroacoustics; 2003, 6; 221-228
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Sensitivity of echo envelope fractal dimension to bottom type and bottom depth - numerical results
    Autorzy:
    Łubniewski, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/332051.pdf
    Data publikacji:
    2003
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    acoustic
    seafloor
    hydroacoustics
    Opis:
    The presented results are a part of those obtained within the author's latest work on application of normal incidence methods in acoustic seafloor characterisation. The work included both theoretical and experimental studies on selection of appropriate methods of seafloor echo processing and feature extraction for characterisation of the bottom type, especially, the study of the usefulness of several echo parameters like fractal dimension or statistical moments of the echo envelope. In this paper, the simulation results of the echo envelope fractal dimension dependence on bottom type and bottom depth are presented. They show that to same extent, fractal dimension of an echo may be useful for bottom identification even in a case of varying depth, however, more detailed, theoretical as well as experimental studies are needed.
    Źródło:
    Hydroacoustics; 2003, 6; 195-198
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Diagnostic of intense proton beams by hydroacoustic means
    Autorzy:
    Albul, V. I.
    Bychkov, V. B.
    Gusev, K. B.
    Demidov, V. S.
    Demidova, E. V.
    Kurchanov, A. F.
    Lukijashin, V. B.
    Vasilijev, S. S.
    Powiązania:
    https://bibliotekanauki.pl/articles/332338.pdf
    Data publikacji:
    2003
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    hydroacoustics
    proton beam
    Opis:
    Detecting and parameters' measurement of intense beams of charged particles in accelerators' laboratories is possible to make in water volumes, using conventional measuring hydrophones with applying of new means and algorithms of hydroacoustic signals' processing. The new experimental results is given and discussed.
    Źródło:
    Hydroacoustics; 2003, 6; 293-294
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Autonomous hydroacoustic sound velocity profiler
    Autorzy:
    Jedel, A.
    Marszal, J.
    Ostrowski, Z.
    Kilian, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/332093.pdf
    Data publikacji:
    2003
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    hydroacoustics
    sound velocity profiler
    Opis:
    The paper presents the autonomous hydroacoustic sound velocity profiler collaborating with ordinary PC by small box included interface & battery charger. The measurement and calibration methods and block diagram of the meter are presented as well as principles of operation, data collection, selection and transmission. There are described three versions of this meter - dropped from "normal" ships, installed in the light hull of submarines and casings in the hulls of variable depth sonar antennas.
    Źródło:
    Hydroacoustics; 2003, 6; 261-266
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Active control of a submerged circular plate
    Autorzy:
    Wiciak, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/331655.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    shipboard noise
    hydroacoustics
    ICSV
    Opis:
    Structure vibrations and structure borne sound may be reduced by passive and active isolation, by passive and active vibration and sound absorbers or by active control. The experiment presented in this paper is a part of an ongoing research project connected with the structural acoustic control in fluid loading structures. The paper presents the opportunity of active control of vibrations and sound through the application of a circular plate containing distributed piezoelectric actuators and sensors. The plate is supported on the edges in a rectangular enclosure and is loaded on one side by heavy fluid (sweet water) and on the other side has contact with a gaseous medium (air). Piezoelectric elements are arranged in sets, each containing four elements located on two concentric circles with different radii.
    Źródło:
    Hydroacoustics; 2008, 11; 441-448
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Examination of the co-operation between echosounder and motion sensor during sea trials
    Autorzy:
    Szymczak, W.
    Buszman, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/332836.pdf
    Data publikacji:
    2009
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    hydroacoustics
    echosounders
    sea trials
    Opis:
    Sea trials with parametric echosounder SES-2000 Compact needs precise information about sounded area of the seafloor. Because of narrow beam both in horizontal and vertical surface each change of antenna position have high influence for results and analyze of measured data. Vessel has to be equipped with a special device, such as multibeam echosounder, to obtain more information about seafloor sounding which is an addition for basic measurements units. Information about bottom topography, from where sounding pulse comes, may give many useful data necessary to correct analyze by echosounder user. There are also parameters such as roll, pitch and heave, which have to be complied. These variables have an influence for shape and echo level. The last parameter analyzed in this article is a difference between vessels heading and bearing. This information comes from heading sensor and GPS receiver.
    Źródło:
    Hydroacoustics; 2009, 12; 217-226
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Compression algorithms for multibeam sonar records
    Autorzy:
    Chybicki, A.
    Moszyński, M.
    Poćwiardowski, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/331502.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    compression algorithms
    sonar records
    hydroacoustics
    Opis:
    Operational requirements of multibeam sonar systems result in very large volumes of datasets stored on local hard drives of operator's station. In this context, the process of archiving acquired data becomes a crucial problem. The paper investigates various lossy and lossless compression methods that can be applied to multibeam sonar data to reduce the size of acquired files without loosing relevant information. The specific character of MBS data allows applying various signal, image and video compression methods to achieve better results than when using standard compression tools. Various techniques of reordering the data were analyzed to achieve best possible compression ratio.
    Źródło:
    Hydroacoustics; 2008, 11; 55-62
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A review of acoustic techniques for habitat mapping
    Autorzy:
    Blondel, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/331523.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    acoustic techniques
    habitat mapping
    hydroacoustics
    Opis:
    Habitat mapping has become an increasingly important application of remote sensing. Active and passive acoustic techniques have greatly improved in the last decade, and their use extends into other spheres to show their economic, legal, political and environmental benefits. This paper reviews the current status of acoustic techniques for habitat mapping. Traditional techniques include echosounders, multibeam systems and sidescan sonars. Passive techniques are also presented, along with geoacoustic inversion and acoustic daylight imaging. The developments in new techniques such as non-linear acoustics, synthetic aperture and interferometry are reviewed. Some emerging techniques are showing increasing potential for habitat mapping, and bistatic sonar, parametric SAS and 3-D chirp profiling are briefly reviewed. Leading international programmes are now making use of these techniques, most often in combination, and their results inform the recommendations for future uses and desired technological developments.
    Źródło:
    Hydroacoustics; 2008, 11; 29-38
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Sound and vibration analysis for 70 m supply vessel in aspect of underwater noise reduction
    Autorzy:
    Weryk, M.
    Kusmirek-Ochrymiuk, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/331657.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    underwater noise reduction
    hydroacoustics
    vessel
    Opis:
    The underwater noise and on-board noise measurement analysis, for 70 m supply ship, are presented in the paper, as well as the noise data for main machinery installed on-board. The results were completed by vibration measurements, then comparative analysis and identification of main sources of sound were executed. The main aim for this project was to analyse noise propagation and identify main noise excitation components resulting in underwater noise propagation. Some preliminary proposals of underwater noise reduction are put forward in the paper.
    Źródło:
    Hydroacoustics; 2008, 11; 431-440
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Acoustic tomography of a turbulent water jet
    Autorzy:
    Gavrilenko, V.
    Didenkulov, I.
    Kustov, L.
    Martyanov, A.
    Nechayeva, M.
    Vyugin, P.
    Pronchatov-Rubtsov, N.
    Powiązania:
    https://bibliotekanauki.pl/articles/331748.pdf
    Data publikacji:
    2003
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    acoustic tomography
    turbulent water
    hydroacoustics
    Opis:
    Measurement of parameters of flowing liquid is one of problems, which have many applications. in the present paper we describe linear and nonlinear acoustic tomography methods for reconstruction of parameters of a turbulent water jet with gas bubbles. Experiments on both techniques are described. in the linear acoustic method it was measured fluctuations of acoustic signal passed through the jet. In the nonlinear acoustic technique it was measured spectra of combination scattering signals in the jet. Experiments were done in a water tank with a submerged water jet. The results of the work demonstrate the possibility of the tomography of flowing bubble liquids.
    Źródło:
    Hydroacoustics; 2003, 6; 91-100
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Emission of hydroacoustics noise of ships with adjustment propeller
    Autorzy:
    Domagalski, J.
    Dobrzeniecki, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/332548.pdf
    Data publikacji:
    2009
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    hydroacoustics noise
    ships
    adjustment propeller
    Opis:
    In the present is furnished results of research of underwater emissions of disturbances in work by ship with adjustable propellers. Verification of level of noise emission was purpose of research dispose by shipping propellers depending on their. Noise have been presented from shipping propellers in background of noise from driving matches dating.
    Źródło:
    Hydroacoustics; 2009, 12; 39-44
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Investigation of the pulse reflected from bottom sediments
    Autorzy:
    Nowak, Ł.
    Szymczak, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/332780.pdf
    Data publikacji:
    2009
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    bottom sediments
    pulse reflected
    hydroacoustics
    Opis:
    The paper describes method of determining time proceeding of the echo pulse arising as an effect of reflection of sampling pulse given with the known form from layered sea bottom. The main goal of presented model is to afford theoretical data that could be used as a point of reference for the experimental data obtained with SES 2000 Standard parametric echosounder. Basic formulas, computation algorithm with its implementation in Matlab language and examples of obtained results are described. Numerical simulations results are compared with experimental data. The laboratory station enabling computing acoustic impedance of sediments and parameters of sampling and echo pulse in different distances from antenna is presented.
    Źródło:
    Hydroacoustics; 2009, 12; 159-166
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The acoustic excitation of newly-formed bubbles
    Autorzy:
    Deane, G.
    Czerski, H.
    Stokes, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/331506.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    gas bubbles
    hydroacoustics
    natural frequency
    Opis:
    Gas bubbles in water act as oscillators with a natural frequency inversely proportional to their radius and a quality factor determined by thermal, radiation, and viscous losses. Newly-formed gas bubbles are excited into breathing mode oscillations immediately after creation, causing them to radiate a pulse of sound. Although the linear dynamics of spherical gas bubbles are well-understood, the mechanism driving the sound production has not been unambiguously identified. Using bubbles released from a nozzle as a model system, it can be shown that sound production is consistant with the rapid change in volume associated with the collapse of an air neck formed immediately after bubble pinch-off. The model is able to adequately describe the production of sound by bubbles released from a nozzle, and can also explain some of the acoustic properties of bubbles fragmenting in fluid turbulence. Laboratory experiments and model calculations of the mechanism are presented. [Work supported by ONR and NSF].
    Źródło:
    Hydroacoustics; 2008, 11; 71-78
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Kohonen networks as ships classifier
    Autorzy:
    Żak, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/331686.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    Kohonen networks
    hydroacoustics
    ships classifier
    Opis:
    The paper presents the technique of artifficial neural networks used as classifier of hydroacoustic signatures generated by moving ship. In the paper firstly the method of feature extraction from hydracoustic signatures using calculation of Mel-Frequency Cepstral Coefficients was discussed. Next the mathod of feature matching using for purpose of object classification basing on hydroacoustic signatures was described. The technique of artificial neural networks especially Kohonen networks which belongs to group of self organizing networks where chosen to solve the research problem of classification. the choice was caused by some advantages of mentioned kind of neural networks for example they are ideal for finding relationships amongst complex sets of data, they have possibility to self expand the set answers for new input vectors. To check the correctness of classifier work the research in which the number of right classification for presented and not presented before hydroacoustic signatures were made. some results of research were presented on this paper.
    Źródło:
    Hydroacoustics; 2008, 11; 467-476
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Acoustic tracking dynamic phenomena in marine ecosystem
    Autorzy:
    Orlowski, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/332782.pdf
    Data publikacji:
    2009
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    acoustic tracking
    marine ecosystem
    hydroacoustics
    Opis:
    Acoustic information, collected in the form of measurements of integrated echo energiesrelated to time and 3D space has been applied at the Sea Fisheries Institute since 1981 to examine the rough statistical relationships between clupeoids distribution in the Baltic and the relevant environmental factors. In this paper it is shown that the data collected can be also applied for very detail observation of dynamic phenomena in marine ecosystem. Two differentiated case studies were selected to show new acoustic applications in specific areas of oceanographic research. In the first case spatial characteristics of fish diel vertical migration in the southern Baltic was surveyed and analysed for the period 1994-2007, against the environmental background. In the second case acoustic sounding was applied to quantify ebullition of methane from Baltic sediments. Both phenomena are strongly dependent on climatic variability. For both cases the final characteristics of the phenomenon was given in the form of video frames, expressing the processes in time. Unique method of echo-recording transformation into video frames was described and applied to analyse the process of ebullition of methane from the seabed.
    Źródło:
    Hydroacoustics; 2009, 12; 167-180
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Application of non-uniform B-Splines of 2-nd order for description vertical distribution of sound speed in water
    Autorzy:
    Makar, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/332798.pdf
    Data publikacji:
    2009
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    hydroacoustics
    B-splines
    sound speed
    Opis:
    Modeling of the vertical distribution of the sound speed in water is useful during determination of the depth on the basis of the acoustic method, modeling refraction phenomena and determination the trajectory of the acoustic wave. For modeling 1D functions (vertical distribution of the sound speed) and 2D (surface of the sea bottom for hydrography) uniform B-Splines was used. In this paper description of uniform B-Splines and description and application of non-uniform B-Splines have been presented.
    Źródło:
    Hydroacoustics; 2009, 12; 133-140
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Acoustical observation of internal waves on the shelf of the Black Sea
    Autorzy:
    Mikryukov, A.
    Popov, O.
    Serebryany, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/332808.pdf
    Data publikacji:
    2009
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    hydroacoustics
    acoustical observation
    Black Sea
    Opis:
    In October, 2007, the Acoustics Institute performed complex acoustical and oceanological studies on a fixed experimental path in the Black Sea, near the Golubaya Bay. Sound signal with linear frequency modulation were used in the experiment. The processing of the experimental records consisted in computing the envelope of the correlation function of the received and transmitted signals and the time dependence of the correlation maxima. A characteristic change in arrival times of the rays is observed for the period of the income of cold near-bottom waters on the path. The quasi-harmonic variation in the arrival times of the ray groups allows one to correctly define the parameters of short-period internal waves accompanying the bore.
    Źródło:
    Hydroacoustics; 2009, 12; 153-158
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Bearing errors in passive sonar stationary target location
    Autorzy:
    Schmidt, A.
    Marszal, J.
    Salamon, R.
    Jedel, A.
    Ostrowski, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/332830.pdf
    Data publikacji:
    2009
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    bearing errors
    passive sonar
    hydroacoustics
    Opis:
    The paper presents a method for determining the coordinates of stationary targets using passive sonar bearing. It identifies the requirements sonar movements must meet to keep the incorrect determination of coordinates to a minimum. It gives the relations, which help determine coordinate errors analytically. Numerical experiments are used to demonstrate the success of the analysis.
    Źródło:
    Hydroacoustics; 2009, 12; 189-200
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Estimation and measurements of resonance scattering on the gas filled polymer microspheres
    Autorzy:
    Secomski, W.
    Klimonda, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/332832.pdf
    Data publikacji:
    2009
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    polymer microspheres
    gas filled
    hydroacoustics
    Opis:
    The gas filled polymer spheres are used either as an ultrasonic contrast agents or controlled drug delivery microcapsules. The power spectrum of the ultrasonic backscattered signal was calculated from the resonance scattering theory for the gas bubbles surrounded by elastic shield. The size distribution of the measured microspheres was included in the calculations. In experiment, the backscattered power spectrum of measured sample was recorded by Siemens Antares ultrasonic scanner. Radio frequency (RF) data was recorded for 2.5 - 6.7 MHz transmitted ultrasonic frequencies. The backscattered spectra were calculated by Matlab software and subtracted from the transmitter spectrum, recorded as an echo from the perfect reflector. The particle size in measured sample was 12 µm mean š 8 µm sd. The resonance frequency, measured under the microscope, was 0.60 MHz for 45 µm diameter microsphere which corresponds to 2.25 MHz for 12 µm sphere. The sample volume was 10cm? and the mean quantity of scatterers was 6ź103/cm?. In conclusion, measured spectra matched those calculated from theory. The use of ultrasonic scanner with RF data output and the high sensitivity, wide bandwidth ultrasonic transducer allows to measure backscattered signal from the very small quantity of resonance scatterers with satisfactory results at 40 dB signal to noise ratio.
    Źródło:
    Hydroacoustics; 2009, 12; 201-208
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The development of a passive acoustic device for monitoring the effectiveness of shockwave lithotripsy in real time
    Autorzy:
    Leighton, T.
    Fedele, F.
    Coleman, A.
    McCarthy, C.
    Jamaluddin, A.
    Turangan, C.
    Ball, G.
    Ryves, S.
    Hurrell, A.
    Stefano de, A.
    White, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/331557.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    passive acoustic device
    shockwave lithotripsy
    hydroacoustics
    Opis:
    This paper reports how laboratory experiments and hydrocode simulations (of cavitation and shock wave propagation) have been used to generate a clinical device which can deliver real benefit to patients with kidney stones. Currently X-ray or ultrasound B-scan imaging are used to locate the stone and to check that it remains targeted at the focus of the lithotripter during treatment. Neither imaging method is particularly effective in allowing the efficacy of treatment to be judged during the treatment session. In this study, laboratory experiment and Computational Fluid Dynamics simulations of the complex interactions between the shock wave, the stone, and the human tissue, have been used to develop a new clinical device. This device, which has been tested in clinical trials, exploits the passive acoustic emissions generated by these interactions, to identify whether the stone remains in the focus, and to what extent the treatment has been successful.
    Źródło:
    Hydroacoustics; 2008, 11; 159-180
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Sea floor classification using multibeam sonar
    Autorzy:
    Łubniewski, Z.
    Chybicki, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/332796.pdf
    Data publikacji:
    2009
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    sea floor classification
    multibeam sonar
    hydroacoustics
    Opis:
    The paper presents the method of seabed identification and classification using multibeam sonar echoes. The proposed approach is based on calculation of a set of parameters of an echo envelope. The parameters are extracted for each consecutive beam allowing the estimation of their dependence on the seafloor incident angle, and then the relation between seabed type and calculated echo parameters and its angular dependence is investigated. The paper concerns the experiment which has been carried out in Gdansk Bay in November 2008, and some comparisons of the results with those obtained during previous experiment in September 2007. The results for several bottom types are presented and discussed. It was confirmed that the information extracted from multibeam seafloor sensing data, e.g. "water column" recordings, may be useful in seafloor characterisation.
    Źródło:
    Hydroacoustics; 2009, 12; 127-132
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Impact of Microphytobenthos Photosynthesis on the Characteristics of the Echo Signal from Baltic Sandy Sediments
    Autorzy:
    Gorska, N.
    Kowalska-Duda, E.
    Marszal, J.
    Schmidt, J.
    Klusek, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/177331.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    hydroacoustics
    backscattering
    microphytobenthos photosynthesis
    Baltic Sea
    Opis:
    The understanding the influence of biological processes on the characteristics of the signals backscattered by the sea floor is crucial in the development of the hydroacoustical benthic habitat classification techniques. The impact of the microphytobenthos photosynthesis on the acoustical backscattering properties of the Atlantic sandy sediments was previously demonstrated by Holliday et al. (2004) and Wildman and Huettel (2012). To account for the sensitivity of the hydroacoustical classification techniques to the backscattering properties of local marine sediments, it is important to understand the microphytobenthos photosynthesis impact for the Baltic Sea where the techniques are being actively developed now. This is the main motivation of the paper. In the paper the influence of the microphytobenthos photosynthesis on the characteristics of the echo signals reflected by sandy sediments in the typical Baltic temperature and the salinity conditions is discussed. The interdisciplinary multiday laboratory experiment was conducted to study the impact of benthic microalgal photosynthesis on the characteristics of the echo signal reflected by sandy sediments. Hydroacoustical data were collected under controlled constant light, temperature and salinity conditions. The oxygen content at different levels of the water column was simultaneously monitored.
    Źródło:
    Archives of Acoustics; 2015, 40, 3; 395-405
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Adaptive telecommunications modems techniques for use in underwater communication systems
    Autorzy:
    Budzińska, I.
    Lasota, H.
    Mazurek, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/331551.pdf
    Data publikacji:
    2003
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    hydroacoustics
    underwater communication systems
    data transmission
    Opis:
    Underwater channel data transmission is one of telecommunications most difficult problems. One way to optimise the transmission may be by adapting transmission techniques used in telecommunications modems. The articles presents two ITU-T standards: V.34 and G.992.1, known as ADSL. The possibilities and limitations of these techniques for underwater communication systems are discussed. The ADSI standard using the DMT modulation seems to be the best.
    Źródło:
    Hydroacoustics; 2003, 6; 285-292
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Principles of computing and displaying the results of detection by underwater systems as part of sound velocity measurements
    Autorzy:
    Raganowicz, A.
    Kilian, L.
    Salamon, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/331744.pdf
    Data publikacji:
    2003
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    hydroacoustics
    underwater systems
    hydrolocation
    hydrocommunication systems
    Opis:
    The paper presents the upgraded system for measurements of sound velocity profiles and for computing and imaging the terms of detection in different hydrolocation and hydrocommunication systems. Three types of computations made by the system's processors are discussed. The most interesting task is to link the propagation routes and ray density with the parameters of the hydroacoustic system to obtain the desired display of the conditions to detect the signal from the background noises. Presented discussion of methodology of determining detection conditions using different forms of range equation gives a more detailed description of this task. In the next part of this paper the software's display function and necessary settings are specified and discussed. In the end two examples of computed detection conditions images (for active and passive sonar) are shown.
    Źródło:
    Hydroacoustics; 2003, 6; 267-274
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of microphytobenthos photosynthesis on the spectral characteristics of the signal reflected from Baltic sandy sediments
    Autorzy:
    Jaśniewicz, D.
    Gorska, N.
    Powiązania:
    https://bibliotekanauki.pl/articles/332045.pdf
    Data publikacji:
    2016
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    hydroacoustics
    backscattering
    microphytobenthos photosynthesis
    Baltic Sea
    Opis:
    The use of hydracoustical techniques to classify benthic fauna and flora is one of the important challenges in present marine research. It is crucial to understand the microphytobenthos photosynthesis impact on the backscattering properties of the sea floor in the Baltic Sea, where the techniques are actively developed now. This motivated our study. The data used in the analysis was collected in the multiday laboratory experiment conducted in the frame of the grant of the National Science Centre, Poland (No. N306 773940). In this experiment, during changing light conditions (light/dark photocycles), the hydroacoustical backscattering data was acquired in the aquarium with a sandy bottom. The constant temperature and salinity conditions, typical for the Southern Baltic, were kept, and oxygen content was monitored. In this paper data collected at 280 kHz, was processed. It was studied how the energy of echo and power spectral density of the echo signal, are sensitive to the microphytobenthos photosynthesis.
    Źródło:
    Hydroacoustics; 2016, 19; 165-171
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    An acoustic study of zooplankton diel vertical migration in the Black Sea
    Autorzy:
    Pezacki, P. D.
    Gorska, N.
    Soloviev, V.
    Powiązania:
    https://bibliotekanauki.pl/articles/332185.pdf
    Data publikacji:
    2017
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    hydroacoustics
    backscattering
    ADCP
    velocity of zooplankton
    Opis:
    Reliable, rapid and non-invasive techniques are important for the monitoring of the ecosystem of the semi-enclosed Black Sea, especially sensitive to the human impact. Hydroacoustic techniques meet these requirements. In the study, the ADCP data (volume backscattering strength and water velocities), collected in the north-east part of the Black Sea in October 2014, were used to understand some biotic and abiotic processes in the environment. The study was motivated by the fact that the used ADCP mounted on the autonomous (moving vertically) platform provided measurements with significantly higher spatial resolution that it was in the previous hydroacoustical studies of Black Sea ecosystem. The main objective of the analysis was to determine the velocity of zooplankton diel vertical migration and understand the processes responsible for the variability of the volume backscattering strength.
    Źródło:
    Hydroacoustics; 2017, 20; 139-148
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Monitoring of ocean current perturbations using acoustic phase variations
    Autorzy:
    Zieliński, A.
    Butowski, M.
    Kraeutner, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/332840.pdf
    Data publikacji:
    2009
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    ocean current perturbations
    acoustics phase variations
    hydroacoustics
    Opis:
    In this paper, we review an acoustic method for measuring both average ocean current speed and sound speed along an acoustic path. The method requires two or more stations on the sea floor, synchronized through a connecting underwater electric cable, that can transmit and receive an acoustic signal and The method is based on reciprocal acoustic transmissions to determine time of flight in both the forward and reverse directions. A specific implementation of this method is proposed. We also consider a novel method for monitoring ocean current perturbations through acoustic phase measurements. In simplest form, a continuous sinusoidal signal is transmitted from one station to a second station. Any variations in ocean current speed will introduce a phase shift in the received signal proportional to the time derivative of the current speed. This effect has been demonstrated through ultrasonic in-air experiments. Finally, the two methods are combined into a single system that continuously measures small-scale ocean current velocity changes.
    Źródło:
    Hydroacoustics; 2009, 12; 237-248
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Low- and high-frequency elastic scattering analysis of fluid-filled, flat-endcapped cylindrical shells proud on a sandy seabed
    Autorzy:
    Tesei, A.
    Groen, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/331639.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    sandy seabed
    at-sea scattering data
    hydroacoustics
    Opis:
    This work presents the analysis of at-sea scattering data by a man-made target which supports the excitation of strong structural waves or resonances, not only at low but even at high frequency (ka>100). The object is a water-filled, flat-endcapped, 2m-long, steel cylindrical shell, measured both at low frequency (2-10 kHz) and at high frequency (120 kHz), where different elastic phenomena are supported and identified. In particular, in the high-frequency sonar images obtained with an AUV-mounted synthetic aperture sonar, significant elastic effects clearly appear, which are interpreted as echoes of a shear wave travelling axially along the cylindrical shell. For interpretation of sonar images it is crucial to understand and predict these supplementary scattering mechanisms.
    Źródło:
    Hydroacoustics; 2008, 11; 388-400
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Large-array signal processing in long-range underwater channels: coherence effects and adaptive approach to the multimode signal control
    Autorzy:
    Malekhanov, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/332804.pdf
    Data publikacji:
    2009
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    signal processing
    underwater channels
    multimode signal control
    hydroacoustics
    Opis:
    The signal coherence degradation in spatial domain is an intrinsic scenario for large-array signal processing if the array size is greater as compared with the coherence length. For underwater sound, study of this issue is physically motivated by the fact that the discrete spectrum signal-carrying modes lose the mutual covariance at long ranges, so the signal coherence loss at the array inputs can be considerable. This is a case of comparative study of the large-array beamformers, optimal one included, aimed at realistic estimations of the coherence-induced effects on their performance. In this paper, we address the other aspect of the problem, namely, the source array synthesis in a random-inhomogeneous multimode channel under the criteria specified for the signal processor in remote receiving array. The criteria of the output SNR and the array SNR gain are considered to be a reasonable choice. An adaptive approach to the multimode signal control by the use of vertical source array is then formulated as an iterative algorithm for the source excitations and the corresponding modal spectrum of the signal wavefield. Computer simulation is performed for the vertical source and receiving arrays operating in the shallow-water channel from the Barents Sea.
    Źródło:
    Hydroacoustics; 2009, 12; 141-152
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Szumy podwodne małej jednostki
    Underwater noise in a small vessel
    Autorzy:
    Dudziak, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/223113.pdf
    Data publikacji:
    2013
    Wydawca:
    Akademia Marynarki Wojennej. Wydział Dowodzenia i Operacji Morskich
    Tematy:
    szumy morza
    hydroakustyka
    identyfikacja
    sea noises
    hydroacoustics
    identification
    Opis:
    Artykuł przedstawia wyniki badań in situ przeprowadzone na akwenie Zatoki Gdańskiej w celu pomiaru i analizy szumów generowanych przez jednostkę morską. Otrzymane wyniki są wstępem do opracowania metod opisu dźwięków generowanych przez jednostki, a także fazy ich przejścia względem obiektu pomiarowego.
    The paper presents the results of investigations carried out in the Bay of Gdańsk in order to measure and analyze noise generated by a maritime vessel. The results obtained are the initial stage in developing methods for describing sounds generated by vessels, as well as phases of their passage with regard to the object measured.
    Źródło:
    Zeszyty Naukowe Akademii Marynarki Wojennej; 2013, R. 54 nr 3 (194), 3 (194); 39-51
    0860-889X
    Pojawia się w:
    Zeszyty Naukowe Akademii Marynarki Wojennej
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Method of determination of acoustic wave reflection points in geodesic bathymetric surveys
    Autorzy:
    Makar, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/320673.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Forum Nawigacyjne
    Tematy:
    hydrografia
    batymetria
    pomiary hydroakustyczne
    hydrography
    batymetry
    hydroacoustics surveys
    Opis:
    The target of the study is development of method of precise determination of water region's co-ordinates for various applications. Selected factors, as dynamics of the sounding vessel and environmental factors are taken into consideration. In spite of possibility of application motion sensors available on the market (more expensive than professional single-beam echo-sounders), an alternative method of determining pitching and rolling has been developed - introduced in a model of precise determining of acoustic ray's reflection co-ordinates - for a ray characterized by non-linear trajectory. It is an alternative for accelerometers used in hydrography and magnetometers with floating cores available on the market. Main theses of the study may be presented as the following: - the vertical sound speed in water has an impact not only on accuracy of the depth measurement but also on trajectory of the acoustic ray, resulting in its non-linear propagation, - having positions of two points known (in their specific locations), there is a possibility of determining pitching and rolling with an accuracy comparable with performance of the motion sensors, - application of the elaborated methods for selected factors determining accuracy of the hydrographic surveys shall influence accuracy of created charts, safety of navigation and efficiency in searching under-water objects in a significant way.
    Źródło:
    Annual of Navigation; 2008, 14; 1-89
    1640-8632
    Pojawia się w:
    Annual of Navigation
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Development of a coupled numerical and experimental approach to hydrodynamic noise estimation
    Autorzy:
    Felicjancik, J.
    Gatz, M.
    Badur, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/175566.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    hydroacoustics
    URN
    noise estimation methods
    CFD modelling
    signal processing
    experimental methods
    model scale tests
    Opis:
    The hydroacoustic signatures of ship propellers can be identified experimentally through measurements of cavitation-induced pressure fluctuations and the accompanying noise distribution at model scale. These measurements have to be performed in a cavitation tunnel at the propellers operating conditions and with sufficient accuracy. In comparison, the numerical approach can be used to present a good general idea of the predicted results. Numerical methods can provide highly accurate tools for noise level and propagation prediction, as well as giving insight into the flow field and other key aspects. They are also not influenced by signal conditioning or disturbance sources present in a physical environment. So we trade scope and precision of the results for time and cost reduction. In this paper, we described both experimental and numerical methods currently in use and present advantages and limitations of the practical application of both.
    Źródło:
    Transactions of the Institute of Fluid-Flow Machinery; 2017, 138; 89-105
    0079-3205
    Pojawia się w:
    Transactions of the Institute of Fluid-Flow Machinery
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Repellence Effect of the New Sound for Underwater Speaker of Hydrofoil
    Autorzy:
    Nakashima, T.
    Kobayashi, N.
    Yamada, H.
    Katsumata, T.
    Yoshida, R.
    Kato, H.
    Okabe, H.
    Kawazu, I.
    Yanase, Y.
    Omine, M.
    Terada, M.
    Sugioka, H.
    Kyo, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/116522.pdf
    Data publikacji:
    2015
    Wydawca:
    Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
    Tematy:
    Underwater Speaker (UWS)
    Hydrofoil
    Underwater Speaker Sound
    Humpback Whale
    New Sound
    Cetaceans
    Acoustics
    Hydroacoustics
    Opis:
    In order to prevent hydrofoil colliding with cetaceans, the underwater speaker (UWS) has been installed to repel cetaceans. Yamada et al. (2012) analyzed and devised the UWS sound as it fits the cetaceans' acoustic properties to prevent the collision furthermore. The new UWS sound was devised and synthesized by Yamada et al. (2015) with expectation of avoiding collision with large cetaceans (Patent applied for, JP2014-171411). In this research project, the new UWS sound was investigated by the playback experiment on humpback whale (Megaptera novaeangliae) and by sighting survey in the actual hydrofoil shipping service route. As a result, a physiological and behavioral change of the humpback whale was observed in the playback experiment of the new UWS sound, and the chance of hydrofoil encountering cetaceans of the new UWS sound was smaller than that of the previous UWS sound. Therefore, the improvement of the new UWS sound was confirmed. Lastly, we wish this research project would contribute toward the safer cruise of hydrofoil in the future.
    Źródło:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2015, 9, 2; 207-211
    2083-6473
    2083-6481
    Pojawia się w:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Development of the Effective Underwater Speaker Sound Modulated by Audible Sound Frequency Range of Large Cetaceans for Avoidance with Ship Collision
    Autorzy:
    Yamada, H.
    Kobayashi, N.
    Nakashima, T.
    Kato, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/116934.pdf
    Data publikacji:
    2015
    Wydawca:
    Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
    Tematy:
    Cetaceans
    Underwater Speaker (UWS)
    Underwater Speaker Sound
    Audible Sound Frequency Range
    Hydrofoils
    Hydroacoustics
    Avoidance with Ship Collision
    Large Cetaceans
    Opis:
    The underwater speaker (UWS) has been installed on high speed vessels; hydrofoils (HF) with low-noise during their cruises, to avoid sudden collisions with large cetaceans, while its performance has remained uncertain because of the problem in quality of the produced sound. Thus, we developed a sound source for the UWS by modulating the sound based on the audible range of major large cetaceans so as to increase its utilities. To investigate the audible sound frequency range of cetacean, we tried two procedures, (1) indirect-estimation from relationship between cetaceans audibility and vocalization, and (2) indirect-estimation from measurements on the cochlear basal membrane. We also synthesized the two new sound sources which we can potentially expect an avoidance with large cetaceans. Through several field experiments with deploy the new sounds we reached a tentative conclusion that the new sound was effective in terms of inducing the cetaceans' avoidance reaction and would be also expected to be applied to other low-noise vessels.
    Źródło:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2015, 9, 2; 213-217
    2083-6473
    2083-6481
    Pojawia się w:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    SLAM – Based Approach to Dynamic Ship Positioning
    Autorzy:
    Wróbel, K. A.
    Powiązania:
    https://bibliotekanauki.pl/articles/116689.pdf
    Data publikacji:
    2014
    Wydawca:
    Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
    Tematy:
    Dynamic Ship Positioning
    Simultaneous Localization and Mapping (SLAM)
    Dynamic Positioning (DP)
    Reference System
    SLAM Method
    SLAM Post-Processing
    Doppler Velocity Log (DVL)
    Hydroacoustics
    Opis:
    Dynamically positioned vessels, used by offshore industry, use not only satellite navigation but also different positioning systems, often referred to as ‘reference’ systems. Most of them use multiple technical devices located outside the vessel which creates some problems with their accessibility and performance. In this paper, a basic concept of reference system independent from any external device is presented, basing on hydroacoustics and Simultaneous Localization and Mapping (SLAM) method. Theoretical analysis of its operability is also performed.
    Źródło:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2014, 8, 1; 21-25
    2083-6473
    2083-6481
    Pojawia się w:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Modeling of performance of a AUV vehicle towards limiting the hydro-acoustic field
    Autorzy:
    Gerigk, M. K.
    Powiązania:
    https://bibliotekanauki.pl/articles/117327.pdf
    Data publikacji:
    2018
    Wydawca:
    Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
    Tematy:
    Autonomous Underwater Vessel (AUV)
    Autonomous Underwater Vehicle (AUV)
    Unmanned Underwater Vehicle (UUV)
    Unmanned Surface Vehicle (USV)
    AUV stealth vehicle
    hydroacoustics
    hydroacoustic field
    sonar
    Opis:
    Some results of research devoted to the modeling of a AUV-Stealth vehicle performance towards limiting its hydro-acoustic field are presented in the paper. At the beginning the AUV-Stealth autonomous underwater vehicle concept is described. Then the method of research is introduced. Next the key design drivers of the AUV-Stealth vehicle are presented. Between them are the AUV-Stealth hull form, arrangement of internal spaces, materials, hull covers, energy supply and propulsion system, etc. Some results of the hydrodynamic and stealth characteristics of the AUV-Stealth vehicle are briefly described. It is presented in the paper that the hull form, construction materials including the covers may affect the AUV-Stealth vehicle boundary layer and wake. This may create some problems of identification of the AUV-Stealth vehicle using a sonar or hydrophone. The final conclusions are presented.
    Źródło:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2018, 12, 4; 687-692
    2083-6473
    2083-6481
    Pojawia się w:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Zastosowanie metod akustycznych i magnetycznych w poszukiwaniu obiektów archeologicznych na przykładzie jeziora Lednica
    The use of acoustic and magnetic methods in the search for archaeological objects through the example of Lednica lake
    Autorzy:
    Pydyn, Andrzej
    Hac, Benedykt
    Popek, Mateusz
    Powiązania:
    https://bibliotekanauki.pl/articles/532028.pdf
    Data publikacji:
    2019
    Wydawca:
    Muzeum Pierwszych Piastów na Lednicy
    Tematy:
    archeologia podwodna
    geofizyka
    magnetometr
    hydroakustyka
    profilograf osadów dennych
    sonda wielowiązkowa
    średniowiecze
    most
    wyspa Ledniczka
    jezioro Lednica
    underwater archaeology
    geophysics
    magnetometer
    hydroacoustics
    subbotto
    profilers
    multibeam probe
    Middle Ages
    a bridge
    Ledniczka island
    Lednica lake
    Opis:
    Noninvasive surveys and prospections are a new dynamic trend in contemporary archaeology. They represent a trend of multidisciplinary analyses of cultural heritage. Due to limited access to technology, these methods are still not widely used in underwater archaeology, in particular in inland reservoirs. For this reason a team from the Department of Underwater Archaeology of the Institute of Archaeology at Nicolaus Copernicus University in Toruń in cooperation with the Maritime Institute in Gdańsk, the Museum of the First Piasts at Lednica and the Scientific Association of Polish Archaeologists (Warsaw branch), planned and completed a project Kolebka Piastów — archeologiczne prospekcje podwodne w rejonie jeziora Lednickiego in 2017. The project was financed by the Ministry of Culture and National Heritage under the following programme: Cultural heritage, priority: The protection of archaeological monuments. In the course of the project a multibeam probe, a subbottom profiler and a magnetometer were used to conduct surveys. If the conditions and assumptions of the project allowed, a direct underwater verification was conducted. Due to multibeam sonar it is possible to obtain a reliable spatial picture of a lake bottom in high resolution, e.g. 100 or more measurement points for each m2 of the bottom, which enables one to conduct a detailed overview of a surface of the research area and objects lying on it. This method turned out to be the most effective during verification and resulted in the localization of a new medieval bridge in Lednica lake. Using a subbottom sediment profiler is at the moment the only noninvasive method of searching for non-magnetic objects sunk into the bottom. After applying it on a recognized object, such as the Poznań bridge, and after receiving the positive results, it may be assumed — with high probability — that this technology will succeed in the search for other wooden archaeological structures located in subbottom sediments. Magnetometric measurements are the next technology which was used in the researched reservoir. They are indispensable when noninvasive large scale searches of metal objects with magnetic signatures are conducted e.g. the objects made of iron or steel. In the area of Lednica lake several objects with a magnetic signature were localized. In the course of research in Lednica, three types of noninvasive prospections were applied: hydroacoustics (a multibeam probe), seismology (subbottom sediment profiler) and magnetics (Caesium magnetometer). Each of these methods helps to localize other objects and gives very interesting results; however, only after all three have been used is it possible to obtain a precise picture of the bottom of the lake together with anomalies, which to a large extent can have anthropogenic origins. It seems that the future of underwater archaeology is closely related to the described noninvasive surveys. Unfortunately it will be more difficult to achieve in shallow inland reservoirs than in sea waters, where these technologies have already been introduced for some time now.
    Źródło:
    Studia Lednickie; 2019, 18; 179-193
    0860-7893
    2353-7906
    Pojawia się w:
    Studia Lednickie
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-45 z 45

      Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies