China
Africa
Explore chapters and articles related to this topic
Navigation and Communication Practice
Published in D. J. House, The Command Companion of Seamanship Techniques, 2007
Masters should note that the ship’s existing radio licence allows full GMDSS use but personnel are expected to pass through a training course and become certificated operators for GMDSS communications. Each vessel will be issued with a nine-digit number known as the Maritime Mobile Service Identity (MMSI) for conducting radio traffic. (The MMSI is obtained from the licensing authority.)
A Review of NAVDAT and VDES as Upgrades of Maritime Communication Systems
Published in Adam Weintrit, Tomasz Neumann, Advances in Marine Navigation and Safety of Sea Transportation, 2019
AIS is a small radio transmitter, which broadcasts information on ship’s identity (e.g., call sign, Maritime Mobile Service Identity (MMSI), position, speed, course, and the like) on maritime VHF band. Therefore, it is usually called AIS transponder.
Digital Selective Calling (DSC)
Published in Graham D. Lees, William G. Williamson, Handbook for Marine Radio Communication, 2020
Graham D. Lees, William G. Williamson
A unique nine-digit code, the MMSI allows individual ship stations to be identified. A similar nine-digit MMSI code, but always starting with the digits ‘00’ identifies a particular coast station (see section 8.27).
A deep learning approach for port congestion estimation and prediction
Published in Maritime Policy & Management, 2023
Wenhao Peng, Xiwen Bai, Dong Yang, Kum Fai Yuen, Junfeng Wu
The primary data used in this study are AIS data and supplementary ship characteristics data. The AIS data record both the dynamic information of ships during the voyage (e.g., time stamp, speed over ground (SOG), course over ground, longitude and latitude) and static information (e.g., vessel type, destination and ship unique identifier). The data is sent through AIS transceivers and collected by satellites or AIS stations. In terms of one ship, its AIS data is a time series data frame tracking its voyage information at fixed time intervals. But for different ships, the time intervals of the records can be slightly different ranging from seconds to 6 minutes (Yang et al. 2019). In this study, we use the following information of ships from AIS data, i.e., time stamp, MMSI, SOG, longitude and latitude. Specifically, Time takes the value of a timestamp representing the exact moment of the observation, which can be transformed to a real-time format (i.e., Y/M/D h:m:s). MMSI represents the Maritime Mobile Service Identity, which is a unique ship identifier. SOG means the speed over ground used to measure the shipping speed in nautical miles. Longitude and Latitude with the format of decimal degrees locate the position of the ship. Specifically, the AIS data used in this study involve the movement information of 3,9571 containerships whose DWT is over 2,000 during 2017/03/01 to 2017/04/01. The raw data size is about 5 GB for 1 month and the overall observation is 76.1 million. The trajectories of those containerships are distributed globally, which is shown in Figure 1.
A method to estimate the capacity of an intersection of waterways in ports
Published in Transportmetrica A: Transport Science, 2019
Xavier Bellsolà Olba, Winnie Daamen, Tiedo Vellinga, Serge P. Hoogendoorn
Both AIS and radar data have several practical applications, such as collision avoidance, vessel traffic services (VTS), maritime security, aids to navigation, search and rescue and accident investigation (Yip 2008; Kujala et al. 2009; Mou, van der Tak, and Ligteringen 2010; Tsou 2010). The use of AIS and radar data for research provides the opportunity to develop statistical analysis of accidents, vessel behaviour, etc., taking into account different circumstances, including weather, time of the day or year, among other things. The relevant information included in the AIS and radar messages for this research is summarized in Table 1. As it can be seen, there are few differences in content between AIS and radar datasets, but these differences do not affect the application of the method and the required inputs are available in both datasets. One main difference between the two datasets is the signal identification. The AIS signals are recorded based on the MMSI, which is a unique number for each vessel and allows to follow their path with the consecutive signals. Although, the radar data records signals without any information for the identification of which vessel is it, the dataset used has already a track number that identifies each vessel trip with a unique number. Recent studies have shown the possibility of using data fusion algorithms to combine the both datasets, which might allow the detection of errors in the AIS data among others (Kazimierski and Stateczny 2015).
Intelligent Tracking of Moving Ships in Constrained Maritime Environments Using AIS
Published in Cybernetics and Systems, 2019
Yuanchang Liu, Rui Song, Richard Bucknall
Autonomous shipping is the future for the maritime industry involving a number of different evolutionary technologies. To ensure the success of autonomous shipping, navigational safety has become the priority and it is important for the ship to autonomously detect other vessels during the operation and consequently take proper evasive actions. To detect other ships’ movements, various navigational sensors such as the Autonomous Identification System (AIS), marine radar, and the Light Detection and Ranging (LIDAR) can be used. Among them, AIS is commonly used as it is fitted to all vessels over 300 gross tonnage (GT) and to many small-sized vessels to enhance the safety and efficiency of maritime navigation according to the International Maritime Organization (IMO) recommendations. The benefits of using the AIS are as follows: 1) the coverage of the AIS information is at least 15–20 nautical miles (Arroyo 2011); 2) the information provided by the AIS is more comprehensive, including maritime mobile service identity (MMSI) number, vessel name, vessel position, speed and etc.; 3) since AIS transmits on VHF radio frequency, it has the capability to continue to be used to detect other ships even in severe environments where the radar detection is compromised (Harati-Mokhtari et al. 2007).