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Wyszukujesz frazę "underwater transport safety" wg kryterium: Temat


Wyświetlanie 1-2 z 2
Tytuł:
Spoofing detection for underwater acoustic GNSS-like positioning systems
Autorzy:
Ochin, Evgeny
Powiązania:
https://bibliotekanauki.pl/articles/135055.pdf
Data publikacji:
2019
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
antiterrorism
GNSS
spoofer
antispoofing
spoofing detection algorithm
underwater vehicle
underwater transport safety
acoustic communication
Opis:
The need for accuracy, precision, and data registration in underwater positioning and navigation should be viewed as no less stringent than that which exists on the sea surface. In the same way in which GNSS (Global Navigation Satellite System) receivers rely on the signals from multiple satellites to calculate a precise position, undersea vehicles discern their location by ranging to the acoustic signals originating from several fixed underwater acoustic sources using the Time-of-Arrival algorithm (ToA) through the Ordinary Least Squares method (OLS). In this article, the scope has been limited to only considering underwater positioning systems in which the navigation receiver is acoustically passive. The receiver “listens” to the buoys, receives their messages and solves the problem of finding its own position based on the geographical coordinates of the buoys. Often, such systems are called GNSS-like Underwater Positioning Systems (GNSS-like UPS). It is important to note the distinction between general purpose GNSS-like UPS (mainly civil systems) and special purpose GNSS-like UPS (mainly military systems). In this article, only general purpose GNSS-like UPS systems have been considered. Depending on the scale of system’s service areas, GNSS-like UPS are divided into global, regional, zonal and local systems. Only local GNSS-like UPS systems have been considered in this article. The spoofing of acoustic GNSS-like UPS works as follows: the acoustic GNSS signal generator transmits a simulated signal of several satellites. If the level of the simulated signal exceeds the signal strength of the real satellites, the acoustic receiver of an underwater object will “capture” the fake signal and calculate a false position based on it. All receivers that fall into the spoofing zone will calculate the same coordinates, while the receivers located in different places will have a mismatch in the XYZ coordinates.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2019, 57 (129); 38-46
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
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
    Wyświetlanie 1-2 z 2

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