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EN
The use of the Automatic Identification System (AIS) devices for ensuring the safety of navigation and the errors occurring when using AIS equipment have been the focus of a number of research studies. The users of AIS equipment installed onboard sea-going vessels are required to familiar with the proper use of the devices and potential errors that may occur. A significant problem revealed in this study is the lack of understanding of potential error sources and the necessity to eliminate such errors prior to transmission of the AIS data message reading of the errors and failure to update the data processed by the AIS system. This results in a hypothesis on the insufficient training of seafarers and their familiarisation with the AIS devices and errors. This research is aimed at increasing the safety of navigation in the Adriatic Sea, as well as other seas, i.e. better accident prevention and protection of human life and material property at sea. The results produced by the research are used as an input for creating a model for enhancing the safety of navigation when using the AIS, through additional training of the seafarers.
EN
The paper presents the method of determining ships traffic stream parameters by means of regression method. The aim of the studies was to determine the correlation between the ship's parameters and the parameters of the fairway. Developing the presented model with information on the position of the vessel's antenna and information on the accuracy of position determination will allow creating a model for predicting the parameters of waterways.
EN
Previous researches on the prediction of fishing activities mainly rely on the speed over ground (SOG) as the referential attribute to determine whether the vessel is navigating or in fishing operation. Since more and more fishing vessels install Automatic Identification System (AIS) either voluntarily or under regulatory requirement, data collected from AIS in real time provide more attributes than SOG which may be utilized to improve the prediction. To be specific, the ships' trajectory patterns and the changes in course become available and should be considered. This paper aims to improve the accuracy in the identification of fishing activities. First, we do feature extraction from the AIS data of coastal waters around Taiwan and build a Recurrent Neural Network (RNN) model. Then, the activity data of fishing vessels are divided into fishing and non-fishing. Finally, based on the testing by feeding various fishing activity data, we can identify the fishing status automatically.
EN
Ship route planning is one of the key issues in enhancing traffic safety and efficiency. Many route planning methods have been developed, but most of them are based on the information from charts. This paper proposes a method to generate shipping routes based on historical ship tracks. The ship's historical route information was obtained by processing the AIS data. From which the ship turning point was extracted and clustered as nodes. The ant colony algorithm was used to generate the optimize route. The ship AIS data of the Three Gorges dam area was selected as a case study. The ships’ optimized route was generated, and further compared with the actual ship's navigation trajectory. The results indicate that there is space of improvement for some of the trajectories, especially near the turning areas.
EN
Optimal ship tracks computed via the VISIR model are compared to tracks recorded by the Automatic Identification System (AIS). The evaluation regards 43 tracks in the Southern Atlantic Ocean, sailed during 2016-2017 by different bulk carriers. In this exercise, VISIR is fed by wave analysis fields from the Copernicus Marine Environment Monitoring Service (CMEMS). In order to reproduce vessel speed loss in waves, a new methodology is developed, where kinematic information from AIS is fusioned with wave information from CMEMS. Resulting VISIR tracks are analyzed along with AIS tracks in terms of their topological features and duration. The tracks exhibit quite diverse topological shapes, including orthodromic, loxodromic, and other paths with complex and dynamic diversions. The distribution of AIS to VISIR track durations is analyzed in terms of several parameters, such as the AIS to VISIR track length and their Fréchet distance. Model features of VISIR affecting the results are discussed and future developments suggested by the results are outlined.
EN
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.
7
EN
Shipment size is unavailable and important in AIS-based trade volume estimates. A method of shipment size estimates based on AIS (Automatic Identification System) data and BP neural network is proposed. The ship's length, width, designed draught, current draught and deadweight ton are input parameters, the actual shipment size of the ship is output value, and the BP neural network is trained to estimate the actual shipment size of the iron ore carriers. Then, the AIS data is used to calculate the iron ore trade volume in 2018. Compared with customs data, the annual error of import volume of China is less than 0.5%. The result shows that the proposed method is accurate and practical.
8
EN
This paper proposes an approach for identifying and characterizing shipping routes using information contained in Automatic Identification System messages broadcasted by ships and recorded by the coastal Vessel Traffic Service centre. The approach consists of using historical Automatic Identification System data to build a graph, where nodes are cells of a grid covering the geographical area being studied and the weights of directional edges are inversely related to ship movements between cells. Based on this graph, the Dijkstra algorithm is used to identify a potential safe route, assumed to be the most used route by ships between two locations. A second graph is created simultaneously, with the same nodes and edges, but with edge weights equal to the average speed of transitions between cells, thus allowing the determination of the average speed profile for any possible path within the graph. The proposed approach is applied to two scenarios: an approach to the port of Lisbon and the entry through the fairway to a RO-RO terminal in the port of Setubal in Portugal.
EN
The traffic density is a basic characteristic of marine traffic for some navigational area. In the case of narrow channels such as Strait of Split (Splitska vrata), apart from the traffic density, the number of simultaneous ship passages is also important as well as ships characteristics. Based on such data, additional navigational safety guidelines and regulations may be planned for the observed area. The purpose of this research is to determine the number of simultaneous ship passages via Strait of Split for a certain period of time. Collected AIS data in SPNMEA format was decoded by AIS Decoder online program to csv file. For five randomly selected days in the summer period, based on AIS data, the number of simultaneous ship passages was determined and ships information presented.
EN
This paper considers the degree of competition among small and medium-sized container ports located in a multi-port gateway region. The level of port competition is evaluated by means of an analysis of the revealed preferences in the port-calling pattern of container feeder vessels deployed on their various links and routes. Unit of analysis is feeder vessel sailing legs and ports stays at/between adjacent container ports. At these ports’ terminals, ships are moored and loading and unloading of containers are performed. The vessel movement data is provided by the Automatic Identification System (AIS). A study of the principal container ports in the Oslo Fjord area is performed, measuring the actual container feeder traffic during the year of 2015. It is demonstrated to which extent ports in the Oslo Fjord region are acting as substitutes, and to which extent they are functioning more as a complement to each other.
11
EN
Automatic Identification System (AIS) is primarily used as a tracking system for ships, but with the launch of satellites to collect these data, new and previously untested possibilities are emerging. This paper presents the development of heuristics for establishing the specific ship type using information retrieved from AIS data alone. These heuristics expand the possibilities of AIS data, as the specific ship type is vital for several transportation research cases, such as emission analyses of ship traffic and studies on slow steaming. The presented method for developing heuristics can be used for a wider range of vessels. These heuristics may form the basis of large-scale studies on ship traffic using AIS data when it is not feasible or desirable to use commercial ship data registers.
EN
The operational limitations are discussed at the IMO as a part of the second generation intact stability criteria. Since it is a first attempt to introduce operational efforts into safety regulations, comprehensive discussions are necessary to realize practically acceptable ones. Therefore this study investigates actual navigation routes of container ships and pure car carriers in the trans-North Pacific Ocean in winter, because they are prone to suffer significant parametric roll which is one of stability failure modes. Firstly, interviews are made to shipmasters who have experiences to have operated the subject ships to identify major elements for route selection in the North Pacific Ocean. Secondly, sufficient number of actual navigation records is collected from Satellite AIS data to derive the weather criteria for the route selection in severe weather condition. Finally, shipmaster’s on-board decision-making criteria are discussed by analysing the ship tracking data and weather data.
EN
With the wide use of AIS system in the world, especially in ports and the waters with heavy traffic, AIS message loss may be related to environmental conditions, obstacle, limitation of VHF technology and AIS network overload, thereby reducing the AIS signal successful reception rate. This paper selected typical AIS data received by Yagi and Omni antennas at the same time in specific waters, uses grid and AIS data recovery technology, establishes the AIS signal coverage model, analyzes signal reception rate of Yagi antenna and Omni antenna of AIS base station, and verified the superiority of Yagi antenna in AIS signal reception rate.
EN
According to the IMO recommendation when the target data from AIS and radar tracking are both available and the association criteria are fulfilled such that the AIS and radar information are considered as for one physical target, then as a default condition in radar equipment, the AIS target symbol and the alphanumerical AIS target data should be automatically selected and displayed only. The article presents research conducted in real conditions on the reliability of information presented by the ship's AIS about the passing distance with the other vessel equipped with AIS and time to pass it by comparing data from the AIS with that presented by ARPA.
EN
The aim of this paper is to understand the real activity and operating situation of container ships in order to improve navigation efficiency. The study focused on the navigation for an entire ship voyage to understand the real activity of container ships using the historical ship navigation based on Automatic Identification System (AIS) data, which is possible so as to unveil the characteristics of real ship activity. The analysis considers ship voyages in the Seto Inland Sea and its oceanic waters, which are the primary traffic routes for container transportation particularly for China, Japan, and South Korea. The results of this study can be used to improve the efficiency of container ships and develop a smoother maritime transportation.
EN
We demonstrate the value in previously disregarded parameters in AIS data, and present a novel way of quickly identifying and characterizing potentially safety critical situations for vessels with a properly configured AIS transponder. The traditional approach of studying (near) collision situations, is through vessel conflict zones, based on vessel location and speed from low resolution AIS data. Our approach utilizes the rate of turn parameter in the AIS signal, at maximum time resolution. From collision investigation reports it is often seen that prior to or at collision navigators perform frenetic rudder actions in the hope to avoid collision in the last second. These hard maneuverings are easily spotted as non-normal rate of turn signals. An identified potential critical situation may then be further characterized by the occurring centripetal acceleration a vessel is exposed to. We demonstrate the novelty of our methodology in a case study of a real ship collision. As the rate of turn parameter is directly linkable to the navigator behavior it provides information about when and to what degree actions were taken. We believe our work will therefore inspire new research on safety and human factors as a risk profiles could be derived based on AIS data.
EN
Virtual electronic aids to navigation are being introduced into the present short range aids to navigation system in the form of Automated Information System radio-based aids. Research is also underway into the development of their equivalents for use in regions that feature hostile environments, are poorly charted and lack any infrastructure whatsoever to support traditional or radio navigation aids. Such aids are entirely virtual in nature and exist only as a digital data object that resides within an electronic navigation chart for display to mariners through an Electronic Chart Display and Information System. They are at present experimental in nature, and are not intended to replace existing physical or radio-based aids to navigation. Results of research are described in terms of fulfilling traditional navigation aid functions and the development of new functions that are only possible using virtual aids. Their advantages in design and implementation are highlighted, as are their limitations and shortcomings as compared to present methodologies. Notable, however, is the approach used to overcome limitations and shortcomings by considering attributes of the physical environment to ensure their proper location and display of correct characteristics. Such an approach is unique in the modern world, yet it emulates ancient methods of navigation using known landmarks and terrain features.
18
EN
It is essential to evaluate safety of marine traffic for the improvement of efficiency and safety of marine traffic. Spread of AIS makes observation of actual marine traffic more easily and faster than before. Besides, description of collision avoidance behaviours of ships are indispensable to simulate a realistic marine traffic. It is important to develop and implement an algorithm of collision avoidance corresponding to a target traffic or target area into the marine traffic simulation because actual actions for collision avoidance depend on circumstances where ships are sailing. The authors developed an automated marine traffic simulation system with AIS data. And in this paper, we proposed a series of systematic procedures for marine traffic simulation including analysing for collision avoidance behaviours using AIS data.
EN
This paper proposes an estimation method for ships on collision courses taking crash astern maneuvers based on a new potential area of water (PAW) for maneuvering. A crash astern maneuver is an emergency option a ship can take when exposed to the risk of a collision with other ships that have lost control. However, lateral forces and yaw moments exerted by the reversing propeller, as well as the uncertainty of the initial speed and initial yaw rate, will move the ship out of the intended stopping position landing it in a dangerous area. A new PAW for crash astern maneuvers is thus introduced. The PAW is developed based on a probability density function of the initial yaw rate. Distributions of the yaw rates and speeds are analyzed from automatic identification system (AIS) data in Madura Strait, and estimated paths of the maneuvers are simulated using a mathematical maneuvering group model.
20
Content available Maritime Traffic Situations in Bornholmsgat
EN
Maritime traffic situations is regulated in the Convention on the International Regulations for Preventing Collisions at Sea (COLREGs), but how well are these rules followed by officers on board vessels? When the world shipping fleet grow and the traffic becomes more intensive, the risk of collision increase. By analysing AIS data from vessels in the traffic separation scheme Bornholmsgat during 24 hours in December 2013, 421 traffic situations were found where the passing distance between the vessels were less than 1.5 nautical miles. The compliance with the Convention on the International Regulations for Preventing Collisions at Sea (COLREGs) seems to be good, but the average avoiding action is less than the recommended manoeuver.
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