Grażyna Grelowska - Publikacje - MOST Wiedzy

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Rok 2020
Rok 2019
  • AUTONOMOUS PLATFORM TO PROTECT MARITIME INFRASTRUCTURE FACILITIES

    Problems regarding the security of maritime infrastructure, especially harbours and offshore infrastructure, are currently a very hot topic. Due to these problems, there are some research projects in which the main goal is to decrease the gap and improve the methods of observation in the chosen area, for both in-air and underwater areas. The main goal of the paper is to show a new complex system for improving the security of the...

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Rok 2018
Rok 2017
  • Acoustic imaging of selected areas of Gdansk Bay with the aid of parametric echosounder and side-scan sonar

    The article presents and analyses the data recorded during sounding of the Gdansk Bay seabed with the aid of a parametric echosounder and a side-scan sonar. The accuracy of seabed structure examination, as a condition for obtaining valuable results, requires correct configuration of echolocation devices and proper calibration of peripheral devices, such as the survey unit geographical position sensor – GPS, the navigation unit,...

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  • Acoustical images of the Gulf of Gdansk
    Publikacja

    Acoustic images of seabed are of interest to specialists in the field of marine engineering, marine navigation, marine archeology, hydrogeology, etc. New technolo gies based on use of elastic waves, predominantly acoustic waves that allow detecting complexity of geometric forms of seabed, ensure progress in studying the bathymetric structure of seafloor. Use of parametric sources of waves generated...

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  • Obrazy akustyczne dna morskiego w wybranych akwenach Bałtyku
    Publikacja

    Metody akustyczne obserwacji obszarów podwodnych mórz i oceanów stosowane są od początku XX wieku. Początkowo były to echosondy nawigacyjne najczęściej składające się z pojedynczych przetworników. Następnie zaczęto stosować sonary do wykrywania obiektów stanowiących przeszkody nawigacyjne pod woda, które miały głównie zastosowanie w marynarce wojennej. W drugiej połowie XX wieku rozpoczęto konstruowanie urządzeń akustycznych, których...

  • Selected acoustic images of the Gdansk Bay
    Publikacja

    The main goal of the paper is to describe the results of sounding the Gdansk Bay seabed by using a parametric sub-bottom profiler, multibeam echosounder and side scan sonar. Quality of dsata obtained during trials depends interalia on a proper location of antenna to reduce influence of pitch, roll and heave motions as well as ship noise.

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  • Theoretical Model of Acoustic Wave Propagation in Shallow Water

    The work is devoted to the propagation of low frequency waves in a shallow sea. As a source of acoustic waves, underwater disturbances generated by ships were adopted. A specific feature of the propagation of acoustic waves in shallow water is the proximity of boundaries of the limiting media characterised by different impedance properties, which affects the acoustic field coming from a source situated in the water layer “ deformed”...

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Rok 2016
Rok 2015
  • Nonlinear properties of the Gotland Deep – Baltic Sea

    The properties of the nonlinear phenomenon in water, including sea water, have been well known for many decades. The feature of the non homogeneous distribution of the speed of sound along the depth of the sea is very interesting from the physical and technical point of view. It is important especially in the observation of underwater area by means of acoustical method ( Grelowska et al ., 2013; 2014). The observation of the underwater...

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  • Study of Noise Propagation for Small Vessels
    Publikacja

    The paper presents the results of the noise propagation analysis in ship structures tested in a number of AHTS (Anchor Handling Tug Supply) vessels. Statistical Energy Analysis (SEA) based on numerical model developed specially for the purpose of this numerical investigation were conducted. This numerical model enabled the analysis of both the structural elements and the acoustic spaces. For the detailed studies 47 points fixed...

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  • Tracking of the broadband source of the underwater noise in the very shallow water conditions
    Publikacja

    The paper contains the result s, both theoretical and experimental , connected with the tracking of the underwater noise source as small ships, pontoon , diver and so on. The pro blem of security in the shallow water area is the challenge for underwater acousticians. In this paper there is take n into account the detection of the sources that move on the surface of the sea or underwater in shallow...

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Rok 2014
  • Akustyka podwodna historia i współczesność
    Publikacja

    Jubileusz pięćdziesięciolecia Komitetu Akustyki Polskiej Akademii Nauk, przypomnienie drogi która przeszła polska akustyka w tym długim, półwiecznym okresie. Na tym tle, w sposób bardziej widoczny jawi się jej stan aktualny, obecne osiągnięcia, a w tym temat akustyki podwodnej. Nazwa „hydroakustyka” lub „akustyka podwodna” określa się obszar nauki i techniki zajmującą się pozyskiwaniem i przekazywaniem informacji w środowisku wodnym...

  • INVESTIGATION OF BOTTOM SEDIMENT STRATIFICATION
    Publikacja

    The main goal of this paper is to find a method to assess remotely the type of sediments on the basis of the signal received using the parametric echosounder. The images of the sea bottom sediments taken by a parametric echosounder show the fine structure of the upper layer of the bottom sediments. The depth of penetration depends on the type of sediment, in fact on the attenuation of acoustic wave. In the paper the method of distinguishing...

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  • RADIATION OF HIGH INTENSITY SOUND BY CIRCULAR DISC BY MEANS OF THE NUMERICAL METHOD
    Publikacja

    The main goal of this paper is to find sound pressure distribution radiated by the circular piezoelectric disc that vibrates with the finite amplitude. There has been presented the pressure distribution close to the radiating surface. Also it is shown the sound pressure distribution in the 3D form. The mathematic modeling was carried out on the base of the nonlinear acoustic equation with the proper boundary condition. The axial...

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  • Underwater Acoustic Imaging of the Sea

    Acoustic waves are a carrier of information mainly in environments where the use of other types of waves, for example electromagnetic waves, is limited. The term acoustical imaging is widely used in the ultrasonic engineering to imaging areas in which the acoustic waves propagate. In particular, ultrasound is widely used in the visualization of human organs - ultrasonography (Nowicki, 2010). Expanding the concept, acoustical imaging...

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Rok 2013
  • Detection of Objects Buried in the Sea Bottom with the Use of Parametric Echosounder
    Publikacja

    The paper contains results of a in situ research main task of which was to detect objects buried, partially or completely, in the sea bottom. Object detecting technologies employing acoustic wave sources based on nonlinear interaction of elastic waves require application of parametric sound sources. Detection of objects buried in the sea bottom with the use of classic hydroacoustic devices such as the sidescan sonar or multibeam...

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  • Diver Observations by Means of Acoustic Methods
    Publikacja

    Searching for objects, especially small ones, moving under water near its the free surface, is always not an easy task. Designing tools for the detection of such targets is a real challenge when the possibility of a terrorist attack is a real threat. This paper presents some aspects of diver detection by means of acoustics methods, both active (side scan sonar) and passive ones (linear receiving antenna). This approach is quite...

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  • Experiment with small objects floating under water in the harbor security aspect.
    Publikacja

    - Rok 2013

    Observation of the underwater area is the element of general trend which primary purpose is to protect and enhance the safety of the selected region. The aim of the paper is to present the acoustic characteristics of typical objects floating on the surface or under the water, which constitute some knowledge on how to detect these objects. Create a catalog of acoustic signatures and acoustic images of objects mostly floating under...

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  • Gdansk Bay sea bed sounding and classification of its results
    Publikacja

    The main goal of this paper is to describe the results of sounding the Gdansk Bay sea bed by using a SES-2000 Standard parametric sub-bottom profiler. Quality of data obtained during trials depends inter alia on a proper location of transducer array to reduce influence of pitch, roll and heave motions as well as ship self noise (resulting from bubbles due to propeller and flow around hull, vibration generated by main engine and...

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  • Investigation of Transmit and Receive Characteristics of Laboratory Model for the Parametric Echosounder
    Publikacja

    - ACTA PHYSICA POLONICA A - Rok 2013

    Investigation and operation of devices based on nonlinear interaction of high-intensity waves have been carried out for several decades. However, it is still a new tool to study the properties of the water environment and especially the upper layers of the seabed. This paper describes the results of tests of the new device that is intended to be applied for sounding underwater areas. The device has been designed and built in collaboration with...

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  • Laboratory investigation with subbottom parametric echosounder SES-2000 standard with an emphasis on reflected pure signals analysis
    Publikacja

    - Rok 2013

    The main goal of the paper is to describe correlations between measurements results of trials taken on Gulf of Gdańsk bottom sounded with parametric echosounder SES-2000 Standard and laboratory research where collected during survey sediments were measured. Stationary tests took place at Gdansk University of Technology where 30 meters long 1.8 meter deep and 3 meters wide water tank is located. Main lobe of antenna was directed...

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  • Multisensor System for the Protection of Critical Infrastructure of Seaport
    Publikacja
    • M. Kastek
    • R. Dulski
    • M. Życzkowski
    • M. Szustakowski
    • P. Trzaskawka
    • W. Ciurapiński
    • P. Markowski
    • M. Karol
    • G. Grelowska
    • I. Gloza... i 2 innych

    - Rok 2013

    There are many separated infrastructural objects within a harbor area that may be considered “critical”, such as gas and oil terminals or anchored naval vessels. Those objects require special protection, including security systems capable of monitoring both surface and underwater areas, because an intrusion into the protected area may be attempted using small surface vehicles (boats, kayaks, rafts, floating devices with weapons...

  • Nonlinear Properties of Seawater as a Factor Determining Nonlinear Wave Propagation
    Publikacja

    - Rok 2013

    Taking practical advantage of nonlinear acoustical interactions occurring in seawater [1, 2] requires knowledge of the parameter of nonlinearity B=A of this medium. The literature does not offer much reports on B=A parameter value for seawater. In the few papers concerning that address the issue, results concerning ocean waters with high salinity and at large depths are given [3], while studies concerning seawater with low salinity...

  • The shallow sea experiment with usage of linear hydrophone array
    Publikacja

    - Rok 2013

    Purpose of this article is to present designed and made linear hydrophone array and the results obtained during in situ trails on Gulf of Gdańsk. The measuring system allowed to localize hydrophones in the selected points and perform measurements in both the horizontal antenna positioning and vertical. Made in this way recordings allow creating accurate 3D imaging of sound intensity/propagation. During research three floating objects...

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  • UNDERWATER NOISE GENERATED BY A SMALL SHIP IN THE SHALLOW SEA
    Publikacja

    Study of the sea noise has been a subject of interest for years. The first work of this scope were published at the turn of the twentieth century by Knudsen (KNUDSEN et al., 1948) and G. Wenz (WENZ, 1962). Disturbances called "shipping noise" are one of the important components of the sea noise. In this work the results of an experimental research of underwater noise produced by a small ship of a classic propulsion are...

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  • Usage of parametric echosounder with emphasis on buried object searching.
    Publikacja

    - Rok 2013

    The purpose of this article is to present the results of investigation to search for buried objects. The paper will contain echograms and other means of visualization from buried pipe placed between area of W?adys?awowo and gas platform and interesting in terms of the number of small and medium-sized unidentified objects found in the muddy bottom at different depths localized in the Gulf of Puck - results will be presented also...

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Rok 2012
Rok 2011
  • Shipping Low Frequency Noise and Its Propagation in Shallow Water

    One of the most significant factor influencing acoustical climate of the sea is underwater noise generated by moving ships. If the considered sea area has features of the shallow water, namely the wave frequency fulfils relation f < 10c/h, where c denotes phase speed of sound, and h is depths of the sea, then in certain distance from the wave source specific image of sound pressure distribution in the mean of wave modes appears....

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  • The Examination of the Upper Layers of the Seabed by the Means of the Acoustic Methods
    Publikacja

    Propagation of acoustic waves in the sea, in particular in shallow sea, depends on several factors. The basic of them are source power and frequency of acoustic waves, spatial distribution inhomogeneous medium in which acoustic wave propagates, and distributions of speed of sound and density of seawater. The coastal conditions, which limit water medium from above (free surface of the sea) and from bottom (the seabed), are no less...

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Rok 2010
Rok 2008
Rok 2006

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