Wyniki wyszukiwania - BazTech

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Capabilities to use passive measurement systems to detect objects moving in a water region

Mironiuk Waldemar, Buszman Krystian

Archives of Transport

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2023

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Vol. 68, iss. 4

137--156

EN

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.

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Detection of floating objects based on hydroacoustic and hydrodynamic pressure measurements in the coastal zone

Buszman Krystian, Gloza Małgorzata

Polish Maritime Research

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2020

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nr 2

168--175

EN

The development of coastal infrastructure and related maritime transport necessitatesthe intensification of vessel traffic monitoring. Navigation systems used in this research are traditionally based on the information transmitted by radio waves. Marine traffic safety requires constant supervision carried out by dedicated systems, the operation of which may be limitedby difficult environmental conditions. The possibilities of supporting navigation systems with underwater observation systems are explored here. The research was carried out using an underwater measurement system. Local disturbances of the hydroacoustic and hydrodynamic field from the moving vessels were analysed. The potential for identifying a moving vessel, for example for offshore infrastructure security purposes, is demonstrated.

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Analysing the impact on underwater noise of changes to the parameters of a ship’s machinery

Buszman Krystian

Polish Maritime Research

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2020

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nr 3

176--181

EN

A ship moving over the surface of water generates disturbances that are perceived as noise, both in the air and under water. Due to its density, water is an excellent medium for transmitting acoustic waves over long distances. This article describes the impact of the settings of a ship’s machinery on the nature of the generated noise. Our analysis includes the frequency characteristics of the noise generated by the moving ship. Data were obtained using an underwater measurement system, and the measured objects were two ships moving on specific trajectories with certain machinery settings. The acquired data were analysed in the frequency domain to explore the possibilities of the acoustic classification of ships and diagnostics of source mechanisms.