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Wyszukujesz frazę "ship detection" wg kryterium: Temat


Wyświetlanie 1-5 z 5
Tytuł:
Capabilities to use passive measurement systems to detect objects moving in a water region
Autorzy:
Mironiuk, Waldemar
Buszman, Krystian
Powiązania:
https://bibliotekanauki.pl/articles/27322537.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
sea transport safety
underwater observation system
ship detection
ship classification
hydroacoustic parametrization
bezpieczeństwo transportu morskiego
system obserwacji podwodnej
detekcja statku
klasyfikacja statków
parametryzacja hydroakustyczna
Opis:
The increase in the use of sea water is the basis for the development of the existing security systems in given areas. Monitoring the navigational situation in a given water area is one of the most important tasks aimed at ensuring the necessary level of safety in maritime traffic. Marine surveillance systems at sea are used for this purpose. As an interesting approach related to the study of the movement of vessels, this paper proposes a method based on the measurement of physical field disturbances generated by objects moving in the sea water. These disturbances can be referred to the upper (air space) and lower (underwater) hemisphere. In the upper hemisphere the motion of the object generates disturbances of the thermal field while in the lower hemisphere disturbances of the acoustic, hydrodynamic, magnetic, electric and seismic fields are generated. Detection of the floating objects and determination of movement parameters is realized mainly by active systems. There are radiolocation systems in the upper hemisphere (radar systems) and echo ranging systems in the lower hemisphere (sonars and echosounders). Monitoring of the upper hemisphere of sea vessels traffic is conducted in a comprehensive manner. The lower hemisphere is in the most cases omitted. Therefore, it is recommended to develop underwater observation systems as a source of additional information about floating objects and thus complement the existing systems used in navigation. However, at present, de spite the technological progress, there is a noticeable lack of the comprehensive solutions in the area of monitoring the vessels movement in the underwater space. Therefore, appropriate action should be taken to recognize this technology gap and increasing the safety of vessel traffic. The aim of the article was to present a fully passive, mobile underwater observation system that uses a number of sensors to monitor the underwater environment parameters, the research methodology and analysis of the obtained results. The method of deploying the measurement system at the selected geographical position and the measurement method are described. Based on obtained results, the analysis of sound pressure disturbances caused by passing ships was performed. A feature extraction method was developed to identify a passing vessel based on low frequency signal parameters.
Źródło:
Archives of Transport; 2023, 68, 4; 137--156
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Integration of elliptical ship domains and velocity obstacles for ship collision candidate detection
Autorzy:
Chen, P. F.
Van Gelder, P.
Mou, J. M.
Powiązania:
https://bibliotekanauki.pl/articles/116538.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
collision avoidance
elliptical ship domain
ship collision candidate detection
time-discrete velocity obstacle algorithm (TD-NLVO)
AIS Data
ship trajectory
collision candidate detection
collision candidate
Opis:
The maritime shipping industry has been making significant contributions to the development of the regional and global economy. However, maritime accidents and their severe consequences have been posing an incrementing risk to the individuals and societies. It is therefore important to conduct risk analysis on such accidents to support maritime safety management. In this paper, a modified ship collision candidate detection method is proposed as a tool for collision risk analysis in ports and waterways. Time-Discrete Velocity Obstacle algorithm (TD-NLVO) is utilized to detect collision candidates based on the encounter process extracted from AIS data. Ship domain model was further integrated into the algorithm as the criteria for determination. A case study is conducted to illustrate the efficacy of the improved model, and a comparison between the existing method and actual ship trajectories are also performed. The results indicate that with the integration of ship domain, the new method can effectively detect the encounters with significant collision avoidance behaviours. The choice of criteria can have a significant influence on the results of collision candidate detection.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2019, 13, 4; 751-758
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ship-iceberg detection & classification in sentinel-1 SAR images
Autorzy:
Heiselberg, H.
Powiązania:
https://bibliotekanauki.pl/articles/117491.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
arctic shipping
ship-iceberg detection
sentinel-1
Synthetic Aperture Radar (SAR)
European Space Agency (ESA)
SAR Imagery
copernicus program
ground range detected
high resolution (GRDH)
Opis:
The European Space Agency Sentinel-1 satellites provide good resolution all weather SAR images. We describe algorithms for detection and classification of ships, icebergs and other objects at sea. Sidelobes from strongly reflecting objects as large ships are suppressed for better determination of ship parameters. The resulting improved ship lengths and breadths are larger than the ground truth values known from Automatic Identification System (AIS) data due to the limited resolution in the processing of the SAR images as compared to previous analyses of Sentinel-2 optical images. The limited resolution in SAR imagery degrades spatial classification algorithms but it is found that the backscatter horizontal and vertical polarizations can be exploited to distinguish icebergs in the Arctic from large ships but not small boats or wakes.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2020, 14, 1; 235-241
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania właściwości promiennych materiałów stosowanych do maskowania okrętów w zakresie podczerwieni
Ships masking in IR band
Autorzy:
Milewski, S.
Dulski, R.
Kastek, M.
Trzaskawka, P.
Powiązania:
https://bibliotekanauki.pl/articles/154518.pdf
Data publikacji:
2011
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
detekcja w podczerwieni
maskowanie statków
detekcja wielowidmowa
IR detection
ship camouflage
vessels detection
multispectral detection
Opis:
Maskowanie okrętów w zakresie podczerwieni jest jednym z podstawowych zadań realizowanych na współczesnym morskim teatrze działań. Efektywnej obrony okrętu wymaga informacji o aktualnym kontraście temperatury okręt - tło. W artykule przedstawiono wyniki pomiarów mocy promieniowania cieplnego wybranych pokryć maskujących jednostek pływających oraz metody modyfikacji sygnatury termicznej okrętów. Analizy teoretyczne poprzedzono badaniami eksperymentalnymi z wykorzystaniem kamer termowizyjnych oraz spektroradiometru.
Masking of ship's thermal signature is one of the key tasks performed in modern naval operations. The main goal of such efforts is to minimize the probability of ship detection and identification, mainly in the aspects of anti-missile defense. In order to obtain effective protection, the actual information on the current thermal contrast between a ship and the background is required. The paper presents the measurement results of the radiant exitance in IR range from various types of camouflage coatings as well as selected methods for modifications of ship's thermal signatures. The assessment of the influence of simulated emissivity change on the radiant exitance emitted from the ship was conducted assuming that the emissivity of the ship equaled to that of the applied coatings. Theoretical analyses were preceded by experimental measurements. The measurements involved the use of measurement-class infrared cameras and LWIR-band Fourier-transform imaging spectroradiometer in order to determine the radiant exitance from several different surface types. The initial experiments were conducted in selected weather conditions and seasons of the year in order to take into account such factors as solar radiation (angle and intensity) and radiation reflected from some chosen elements of the surrounding scenery.
Źródło:
Pomiary Automatyka Kontrola; 2011, R. 57, nr 10, 10; 1234-1237
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Hough transform in the classification process of inland ships
Autorzy:
Bobkowska, Katarzyna
Wawrzyniak, Natalia
Powiązania:
https://bibliotekanauki.pl/articles/135214.pdf
Data publikacji:
2019
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
Hough transform
k Nearest Neighbors (kNN)
image processing
classification
ship recognition
line detection
Opis:
This article presents an analysis of the possibilities of using image processing methods for feature extraction that allows kNN classification based on a ship’s image delivered from an on-water video surveillance system. The subject of the analysis is the Hough transform which enables the detection of straight lines in an image. The recognized straight lines and the information about them serve as features in the classification process. Above all, this approach allows ships to be recognized, which can then be characterized by a specific representation and shape. Recreational units that are often seen on inland waters were classified correctly using this method. Each analyzed camera image was previously prepared – brought to the form where the ship was visible from the side and the background removed (they were monochromatic – white). The results obtained in this work will allow for the development of the final ship classification method based on camera images. This method is a significant part of the emerging system prototype, which is implemented as part of the Automatic Ship Recognition and Identification (SHREC) project.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2019, 58 (130); 9-15
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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