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Wyszukujesz frazę "Hydroacoustics" wg kryterium: Temat


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
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:
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:
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:
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:
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:
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:
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:
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:
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:
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:
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:
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:
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

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