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Wyszukujesz frazę "side-scan sonar" wg kryterium: Temat


Wyświetlanie 1-10 z 10
Tytuł:
Extraction of seabed geomorphologic features of Svalbard fjords using high-resolution side scan sonar
Autorzy:
Tęgowski, J.
Giżejewski, J.
Zieliński, A.
Powiązania:
https://bibliotekanauki.pl/articles/331637.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
Svalbard fjords
side scan sonar
sea bed
Opis:
This paper presents results of a study on the relationship between features of side scan sonar acoustic imagery of zones with active bedforms and geomorphologic seafloor characteristics. Acoustic measurements were conducted in Hornsund, a Svalbard fjord representing a periglacial environment with great intensity of morphodynamic processes and rapidly progressing changes of tidewater glaciers. Due to the intensity of these processes, Arctic fjords are the most promising areas to study the effects of climate change on the ecosystem. Acoustic identification of sedimentary structures and morphological forms created by currents and iceberg transport of glacier sediment away from the ice margin was performed. The spectral and fractal features of the recorded signals were analysed. The proposed analysis scheme allows identification of the morphodynamic active zones in the changing Arctic fjord environments. Measurements of acoustical features of seafloor surface were made during the 2006 Arctic cruise of r/v Oceania.
Źródło:
Hydroacoustics; 2008, 11; 401-411
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Shape From Shading Technique for Side Scan Sonar Images
Autorzy:
Bikonis, K.
Moszynski, M.
Lubniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/258963.pdf
Data publikacji:
2013
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
side scan sonar data processing shape from shading
Opis:
Digital signal processing technology has revolutionized a way of processing, visualisation and interpretation of data acquired by underwater systems. Through many years side scan sonars were one of the most widely used imaging systems in the underwater environment. Although they are relatively cheap and easy to deploy, more powerful sensors like multibeam echo sounders and sonars are widely used today and deliver 3D bathymetry of sea bottom terrain. Side scan sonar outputs data usually in a form of grey level 2D acoustic images but the analysis of such pictures performed by human eye allows creating semi-spatial impressions of seafloor relief and morphology. Hence the idea of post-processing the side scan sonar data in a manner similar to human eye to obtain 3D visualisation. In recently developing computer vision systems the shape from shading approach is well recognized technique. Applying it to side scan sonar data is challenging idea used by several authors. In the paper, some further extensions are presented. They rely on processing the backscattering information of each footprint (pixel in sonar image) along with its surroundings. Additionally, a current altitude is estimated from the size of shadow areas. Both techniques allow constructing 3D representation of sea bottom relief or other investigated underwater objects.
Źródło:
Polish Maritime Research; 2013, 3; 39-44
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determining hotspots of sonar targets related to chemical munitions dumped in Bornholm Deep and Gotland Deep using GIS
Autorzy:
Majcher, J.
Grabowski, M.
Bełdowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/332429.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
chemical warfare agents
side scan sonar
geographic information system
Opis:
According to the Helsinki Commission report from 1994 around 15000 tonnes of chemical warfare agents were dumped to the Baltic Sea after World War II as part of the demilitarization process of the former Nazi Germany. Continuing corrosion of metal encasements makes the dumped munitions a ticking time-bomb, which could potentially harm the whole Baltic Basin. The presented work addresses important aspects for a proper evaluation of the threat; side scan sonar survey data storage and analysis of a spatial distribution of the sonar targets potentially related to chemical weapons. The chosen software environment was GIS oriented. ESRI ArcGIS built-in tools were used to determine the hotspots of the targets on the official post-war munitions dumping sites; Gotland Deep and Bornholm Deep. The automation process of mapping in GIS was also proposed. Therefore, a holistic approach for digital mapping of the sonar targets related to dumped munitions was created.
Źródło:
Hydroacoustics; 2017, 20; 121-128
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the accuracy of shoreline mapping in inland navigational charts (Inland ENC) using photogrammetric and sonar images
Autorzy:
Łubczonek, Jacek
Łącka, Małgorzata
Zaniewicz, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/134946.pdf
Data publikacji:
2019
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
photogrammetry
navigation chart
hydrography
side scan sonar
accuracy assessment
mapping
Opis:
Shoreline mapping is one of the key stages in navigational charting. In terms of navigation, the shoreline marks the boundary of a river, which is often equivalent to the navigable water area. In cartographic terms, it is an important topological element between different objects that are adjacent to it. Currently, topographic objects are often mapped using photogrammetric materials obtained from various altitudes – satellite, airborne or low, which is associated with the use of an airborne UAV. Depending on the type of materials, the shoreline can be obtained in vector form with differing situational accuracy and differing degree of detail. In addition to the standard methods of processing vector data, the research in this paper also included the use of sonar images, enabling the detection of the shoreline with the use of a surveying hydrographic unit. On the basis of the collected photogrammetric and sonar images of different spatial resolution, an analysis of the accuracy of shoreline mapping was performed in terms of the situational accuracy and the level of detail in its representation. The results of the research provided the basis for the determination of dedicated remote sensing materials enabling the development of maps for inland navigation.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2019, 58 (130); 45-54
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inversion of side scan sonar motion and posture in seabed geomorphology
Autorzy:
Tao, W.
Liu, Y.
Hu, H.
Powiązania:
https://bibliotekanauki.pl/articles/258774.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
side scan sonar
image matching
image fusion
neutral network
motion inversion
Opis:
Side scan sonar measurement platform, affected by underwater environment and its own motion precision, inevitably has posture and motion disturbance, which greatly affects accuracy of geomorphic image formation. It is difficult to sensitively and accurately capture these underwater disturbances by relying on auxiliary navigation devices. In this paper, we propose a method to invert motion and posture information of the measurement platform by using the matching relation between the strip images. The inversion algorithm is the key link in the image mosaic frame of side scan sonar, and the acquired motion posture information can effectively improve seabed topography and plotting accuracy and stability. In this paper, we first analyze influence of platform motion and posture on side scan sonar mapping, and establish the correlation model between motion, posture information and strip image matching information. Then, based on the model, a reverse neural network is established. Based on input, output of neural network, design of and test data set, a motion posture inversion mechanism based on strip image matching information is established. Accuracy and validity of the algorithm are verified by the experimental results.
Źródło:
Polish Maritime Research; 2017, S 2; 81-88
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automatyczna detekcja obiektów sonarnych
Automatic detection on sonar objects
Autorzy:
Wąż, M.
Grządziel, A.
Nowak, D.
Powiązania:
https://bibliotekanauki.pl/articles/972124.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Przyrodniczy we Wrocławiu
Tematy:
pomiary hydrograficzne
sonar boczny
obraz sonarowy
detekcja obiektów
hydrographic survey
side scan sonar
sonar imagery
object detection
Opis:
Współczesne systemy sonarowe wykorzystywane są głównie do poszukiwania i wykrywania obiektów podwodnych, które mogą wpłynąć na bezpieczeństwo pływania i postoju jednostek pływających. Zadaniem operatora takich systemów jest optymalne ustawienie zobrazowania oraz odpowiedni dobór parametrów operacyjnych umożliwiających detekcję ech a następnie identyfikację wykrytych celów. Operator dokonuje korekty uzyskanych danych sonarowych, poprawiając tym samym jakość zobrazowania i możliwości interpretacji wyników pomiarów. W artykule rozpatrywanym problemem badawczym jest przekształcanie obrazów, dokonywanie korekcji geometrycznej oraz ekstrakcja obiektów z tła obrazu sonarowego. Zaprezentowana metoda automatycznego wyszukiwania obiektów wykorzystuje cechy morfologiczne sonogramów oraz geometryczne i arytmetyczne metody przetwarzania sygnałów stosowane do obróbki i analizy obrazów cyfrowych. Na etapie wyszukiwania cech obiektów sonarowych wykorzystano metody minimalno-odległościowe stosowane w rozpoznawaniu obrazów. Opracowana aplikacja umożliwiła przeprowadzenie eksperymentu badawczego przedstawiającego kolejne etapy detekcji obiektów sonarowych. Otrzymane wyniki mogą wskazywać na poprawność przyjętych założeń do badań oraz poprawność ich przeprowadzenia.
Contemporary sonar systems are used mainly to search for and detect underwater objects which might affect the safety of navigation or the safety of moored watercraft. The task of the sonar operator is to display the optimal settings of the sonar image and to select the proper operational parameters that enable detection and identification of hidden targets. The operator performs corrections of the recorded sonar data, thereby improving the image quality and the ability to interpret the survey results. The paper deals with the research problem of changing display images, conducting geometric corrections, and extracting objects from the sonar imagery background. The presented method for the automatic searching of objects utilizes the morphologic features of sonograms and geometric and arithmetic methods of digital signal processing. In searching for the features of a sonar target, the minimal-distance methods used in pattern recognition were applied. The developed application makes it possible to perform research experiments that follow the stages of sonar detection of objects. The obtained results can indicate the validity of the research assumptions and the appropriateness of the methods used.
Źródło:
Acta Scientiarum Polonorum. Geodesia et Descriptio Terrarum; 2013, 12, 1; 29-41
1644-0668
Pojawia się w:
Acta Scientiarum Polonorum. Geodesia et Descriptio Terrarum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Submarine landslides on the slope of a sandy barrier : A case study of the tip of the Hel Peninsula in the Southern Baltic
Autorzy:
Rudowski, R.
Rucińska-Zjadacz, M.
Wróblewski, R.
Sitkiewicz, P.
Powiązania:
https://bibliotekanauki.pl/articles/2059851.pdf
Data publikacji:
2016
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
underwater mass movements
sandspit
digital terrain model (DTM)
side-scan sonar
sub–bottom profiling
Opis:
The aim of the study is to present the occurrence of landslides on the submarine slope of a sandy barrier. The scale and significance of this phenomenon is discussed. The study area is the Hel Peninsula. It is a 35 km long young sandy spit. The landform is prograding into the deep part of Gdańsk Bay, and the underwater extension of its tip is a steep sandy slope. The tip is still poorly investigated, as it was a military area closed to researchers until 2003. The first detailed survey of the tip on the seabed was conducted aboard the research vessel “IMOR”. A multibeam echosounder, a sub-bottom profiler and a side-scan sonar were used, while grab and core samples of sediment were obtained. Many forms, commonly created as the result of underwater mass movement, were recognized and determined (main scarps, main bodies, landslide steps, landslide foots, series of small slides, “sheet” slides and structural slides). On the one hand, the landslide processes that occur in the tip of the Hel Peninsula are related to the natural development of sandy spits. On the other hand, they threaten the shore’s stability. The genesis of the landslides is still not known.
Źródło:
Geological Quarterly; 2016, 60, 2; 407--416
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conditions for multiple acquisition of echoes from stationary targets in successive transmissions of active sonars
Autorzy:
Kilian, Lech
Schmidt, Aleksander
Rudnicki, Mariusz
Powiązania:
https://bibliotekanauki.pl/articles/24201958.pdf
Data publikacji:
2022
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
echosounder
sonar
side scan sonar
multiple echo
beam geometry
scanning speed
echosonda
sonar boczny
echo wielokrotne
geometria belki
prędkość skanowania
Opis:
In echolocation, the highest possible number of contacts with a detected target is clearly decisive on the possibilities of echo processing to optimise the estimation of distinctive characteristics of the observed target. In hydrolocation, the slow propagation of acoustic waves in water reduces the number of contacts of echosounders and sonars with detected targets. The article considers model conditions for acquiring multiple contacts with stationary targets detected by various sounding methods - with echosounders, classic active sonars and side looking sonars. Appropriate formulas explicitly linking the possible number of echo signals from the target in a specific geometry of the survey performed at the assumed speed are presented. These formulas are intuitively clear and not very complicated, but their value lies in the ability to instantly combine the vessel speed with the sounding effects, and may be a clear argument for imposing a low sounding speed, which make it difficult to steer the vessel.
Źródło:
Vibrations in Physical Systems; 2022, 33, 3; art. no. 2022308
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automated approach to classification of mine-like objects using multiple-aspect sonar images
Autorzy:
Wang, X.
Liu, X.
Japkowicz, N.
Matwin, S.
Powiązania:
https://bibliotekanauki.pl/articles/91790.pdf
Data publikacji:
2014
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Tematy:
object
sea bed
multiple side-scan sonar
Dempster-Shafer theory
DS concept
classifier
imbalance
imbalanced problem
multi-instance class
Opis:
In this paper, the detection of mines or other objects on the seabed from multiple side-scan sonar views is considered. Two frameworks are provided for this kind of classification. The first framework is based upon the Dempster–Shafer (DS) concept of fusion from a single-view kernel-based classifier and the second framework is based upon the concepts of multi-instance classifiers. Moreover, we consider the class imbalance problem which is always presents in sonar image recognition. Our experimental results show that both of the presented frameworks can be used in mine-like object classification and the presented methods for multi-instance class imbalanced problem are also effective in such classification.
Źródło:
Journal of Artificial Intelligence and Soft Computing Research; 2014, 4, 2; 133-148
2083-2567
2449-6499
Pojawia się w:
Journal of Artificial Intelligence and Soft Computing Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of natural conditions on the imaging of the bottom of the Gdańsk Bay by means of the side scan sonar
Autorzy:
Witos-Okrasińska, D.
Grelowska, G.
Kozaczka, E.
Powiązania:
https://bibliotekanauki.pl/articles/258936.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
side scan sonar imaging
Gdańsk Bay seabed
refraction of sound ray in sea
influence of ship’s movement on the wave on underwater imaging
Opis:
The interest in underwater resources is the reason for the development of modern hydroacoustic systems, including side sonars, which find numerous applications such as: research of seabed morphology and sediment characteristics, preparation of sea sediment maps, and even in special cases of biocenoses such as sea grass meadows, detection of specific targets at the bottom such as shipwrecks, mines, identification of suitable sites for maritime infrastructure. Such applications require precise information about the position of the objects to be observed. Errors affecting the depiction of the bottom using hydroacoustic systems can be divided into errors associated with improper operation of measuring and support devices, systematic errors and random errors. Systematic errors result from the changing conditions prevailing in the analyzed environment affecting the measurement system. The errors affecting the correct operation of hydroacoustic systems can include: changing angle of inclination of the beam caused by the vessel’s movement on the wave or refraction connected to changes in the sound speed as the depth function.
Źródło:
Polish Maritime Research; 2018, S 1; 104-110
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

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