Introduction:
Automatic Identification System (AIS) is a system that utilizes Very High Frequency System to transmit ship movement and technical data at specified intervals. Terrestrial AIS data is captured by ground stations in ports and along coasts; satellite-AIS (S-AIS) data is recorded by specially equipped satellites.
The system’s protocol specifies the kind of data that will be sent and what technology will be used. The data is separated into two categories: dynamic data from ship sensors, which contains trip-related information like vessel live position and current speed, and static data, which includes parameters like the ship’s name and destination.
AIS Data in Maritime Operations:
In order to keep track of vessel, the industry makes extensive use of the AIS. Ships having AIS transponders send data continually, including location, speed, trade route, and identity. Improving maritime safety has been made possible by the use of this real-time data.
Safety:
AIS data is essential for collision avoidance since it gives ships up-to-date information on the positions and movements of other surrounding ships. This helps to avoid mishaps, particularly on crowded waters where vessels frequently intersect one another.
Rescue Operations:
By giving precise and current information on a vessel’s last known position, AIS supports search and rescue operations. In an emergency, this helps authorities immediately reduce the search area and speed up rescue efforts.
Regulatory Compliance and Transparency:
AIS data plays a crucial role in assuring regulatory compliance in the maritime sector, as well as transparency. AIS encourages transparency by transmitting data about a vessel’s identification and actions. This facilitates the monitoring and enforcement of international regulations, notably those pertaining to bunkering operations.
Guidelines for AIS:
Regulation 19 of SOLAS Chapter V – Carriage requirements for ship borne navigational systems and equipment – defines what navigational equipment must be carried on board ships according to their type.
Carriage of AIS is mandatory for ships of 300 GT and upwards engaged on international voyages, cargo ships of 500 GT and upwards not engaged on international voyages and all passenger ships built after 2002 or operated after 2008 irrespective of size. Smaller vessels may also use AIS on a voluntary basis. Fishing vessels of more than 15 meters are also required to install AIS.
The AIS shall be maintained in operation at all times except where international agreements, rules or standards provide the protection of navigational information (SOLAS).
Use of AIS:
The development of AIS was initiated in 1994 as a joint project between several parties such as the International Maritime Organization (IMO) and the International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA). In 1998, IMO 11 amended regulations about use of AIS to the International Convention for the Safety of Life at Sea (SOLAS) (IMO,1974).
AIS was initially planned as an aid for collision avoidance and uses frequencies from the Very High Frequency (VHF) band to broadcast messages. Land based AIS collectors can distinguish AIS messages up to 40-50 nautical miles offshore. Traffic further offshore will not be identified by these receivers. However, a follow up study found that AIS signals can be recognized by satellite based AIS recipients situated in altitudes of up to 1000 km. With the capability of gathering information through satellites, the use of AIS information in studies on maritime transportation has ended up progressively predominant. In expansion to utilizing it for occurrence for fleet and cargo following and by harbour control to oversee traffic, it can be used in estimation of shipping outflows from fuel utilization and picking up knowledge on specialized and operational vitality efficiency in shipping.
SOG
Measured speeds in the AIS messages are recorded by the Global Positioning System (GPS) as speed over ground in knots. Speed through water does not consider the resistance on the vessel or the speed of the vessel relative to the currents of the surrounding water. Speed through water will be different from speed over ground when there is a tidal stream. For example will a vessel sailing at a speed of 14 knots with a tidal stream acting in the opposite direction at a speed of two knots experience a speed through water of 16 knots.
Transmission of AIS Messages:
AIS transmissions have two dedicated VHF frequencies, designated as channel A and channel B. In order to share the limited frequencies available, all transponders follow a transmission system known as Time Division Multiple Access (TDMA) making each transponder transmit for very short and accurately controlled time periods in designated time slots.
TDMA divides the time into frames, each of one minute length, where the time of each transponder is synchronised based on GPS. Each time frame is again divided into 2250 equal slots. One slot is approximately 256 bits, which is the equivalent of 40-50 text characters. As a result there are normally 4500 time slots per minute for AIS transmissions over the two frequencies
Transponders allocate information into time slots under three different modes. The first mode, “Autonomous and Continuous Mode”, autonomously assigns the slots it is transmitting in. If a transponder detects that there are other transmissions in the same slot i.e. interference, it will change its slot. In the second mode, “Assigned Mode”, a shore station will conduct all AIS transmissions within an area and will allocate slots to individual transponders. The last mode,
is the “Polling Mode” where the AIS transponder only sends information whenever interrogated by an authorised transponder.
Quality Issues Related to AIS Data:
Originally designed for ship-to-ship communication, AIS systems were not initially intended for space-based receivers. The expansive coverage area of satellites, exceeding the design parameters of AIS receivers, can lead to interference issues with ship AIS signals. This interference is particularly problematic in areas of high traffic density, potentially causing misidentification of signals and resulting in inaccurate vessel tracking. In regions covered by multiple base stations, AIS data from the same vessel may receive different time stamps for identical position stamps.
Vessel identifiers in AIS messages, such as IMO number, MMSI number, Call Sign, and/or Vessel Name, pose safety concerns when vessels broadcast under the identity of another using the same IMO number in a given area. Erroneous data manifests in various forms, with one common issue being significant time or space gaps between successive AIS records. This can arise from turning off the AIS transmitter or navigating in areas with limited satellite coverage during open-sea voyages.
Satellite-based raw data sampling rates, contingent on the number of satellite providers utilized by the AIS provider, can result in substantial data gaps. Additionally, proximity between a VHF antenna and the AIS, broadcasting on the same spectrum, may cause interference. Manually logged data, such as draught, can be inaccurately recorded by vessel personnel during visual inspections and data input into the AIS. The reliability of manually logged data depends on the on-board equipment setup, where errors can occur, for instance, if the radar is incorrectly configured, leading to inaccurate rate of turn data. The primary quality issue addressed in this thesis pertains to data gaps, necessitating certain modifications for resolution.
AIS Data in Bunkering Services:
Vessel Tracking:
AIS data enables real-time tracking of vessels engaged in bunkering operations. This capability allows bunkering service providers, port authorities, and regulatory bodies to monitor and manage vessel movements during the fueling process.
Collision Avoidance during Bunkering:
Leveraging AIS data during bunkering operations enhances safety by providing real-time information on the positions of bunkering vessels and other ships in the vicinity. This significantly reduces the risk of collisions, ensuring the smooth flow of bunkering services without compromising safety.
Regulatory Compliance and Documentation:
The integration of AIS data in bunkering services aids in regulatory compliance. Bunkering operations can be closely monitored to ensure adherence to international regulations and local laws. The transparency provided by AIS data also facilitates the documentation of bunkering activities for regulatory purposes.
Efficiency and Optimization:
AIS data offers valuable insights into vessel traffic patterns. Bunkering service providers can analyze this data to identify strategic locations for bunkering operations, minimizing travel distances and optimizing the overall efficiency of the bunkering process.
Global Impact of AIS Data in Bunkering Services:
Standardization and Collaboration:
Utilizing AIS data in bunkering services plays a crucial role in standardizing practices on a global scale. This standardization facilitates collaboration among diverse maritime stakeholders, including bunkering service providers, port authorities, and regulatory bodies. Consequently, it establishes a more cohesive and regulated maritime environment.
Safety in International Waters:
In the expansive realm of international waters, where vessels from various countries navigate common routes, AIS data contributes significantly to enhancing safety. Coordinating bunkering operations becomes more effective, reducing the likelihood of incidents with potential far-reaching consequences.
Environmental Responsibility:
Amidst the increasing global emphasis on environmental sustainability, AIS data becomes a valuable tool in promoting responsible bunkering practices. Monitoring vessels for compliance with environmental regulations and encouraging the use of cleaner fuels are facilitated through initiatives driven by comprehensive data analysis.
Data-driven Decision Making:
The integration of AIS data empowers bunkering service providers by providing capabilities for data-driven decision-making. Through the analysis of historical AIS data, providers can discern trends, optimize routes, and improve overall operational efficiency
Challenges and Future Developments:
Data Security and Privacy Concerns:
The increased reliance on AIS data raises concerns about data security and privacy. As vessels transmit sensitive information, it becomes crucial to implement robust cybersecurity measures to protect against unauthorized access and potential misuse of data.
Technological Advancements:
Continuous technological advancements, such as the development of more advanced AIS systems and the integration of artificial intelligence, are likely to further enhance the capabilities of AIS in bunkering services. These developments could lead to even more efficient and automated bunkering processes.
Global Regulatory Frameworks:
The establishment of global regulatory frameworks that govern the use of AIS data in bunkering services is essential. Harmonizing regulations across different regions will facilitate smoother operations and ensure a consistent approach to safety and compliance.
Conclusion:
In summary, integrating AIS data into the bunkering process significantly improves efficiency, safety, and transparency in the maritime industry. Real-time vessel tracking enhances communication, reduces risks, and streamlines operations. This technology also promotes environmental sustainability by optimizing fuel consumption. However, it is crucial to address cybersecurity and privacy concerns. Overall, AIS integration marks a crucial step toward a more efficient, safer, and sustainable bunkering process in the maritime sector.
– Krupali Gajara