by owners of marine seabed infrastructure, such as cables or pipelines, to monitor the activities of vessels close to their assets in close to real time. This information can then be used to trigger alerts to inform the owner and potentially avoid an incident where damage to the asset might occur. Fleet and cargo tracking Internet disseminated AIS can be used by fleet or ship managers to keep track of the global location of their ships. Cargo dispatchers, or the owners of goods in transit can track the progress of cargo and anticipate arrival times in port. Statistics and economics the United Nations Statistics Division organized the AIS Data Week to experiment with AIS data analysis and provide statistics to the UN Global Platform. It covered a number of use case studies by various statistical offices, and the AIS Handbook was developed to capture the experience from this experimentation: Faster economic indicators: Time in port and port traffic Maritime indicators Official Maritime statistics: Port visits Completing statistics on Inland waterways Mapping fishery activities Ships in distress Greenhouse gas emissions of ships (, , and calculation) Nowcasting of Trade Flows in Real-Time Experimental Statistics of Daily number of vessels Real-Time Data on Seaborne Dry Bulk Commodities Mechanism Basic overview AIS transceivers automatically broadcast information, such as their position, speed, and navigational status, at regular intervals via a VHF transmitter built into the transceiver. The information originates from the ship's navigational sensors, typically its global navigation satellite system (GNSS) receiver and gyrocompass. Other information, such as the vessel name and VHF call sign, is programmed when installing the equipment and is also transmitted regularly. The signals are received by AIS transceivers fitted on other ships or on land based systems, such as VTS systems. The received information can be displayed on a screen or chart plotter, showing the other vessels' positions in much the same manner as a radar display. Data is transmitted via a tracking system which makes use of a self-organized time-division multiple access (SOTDMA) datalink designed by Swedish inventor Håkan Lans. The AIS standard comprises several substandards called "types" that specify individual product types. The specification for each product type provides a detailed technical specification which ensures the overall integrity of the global AIS system within which all the product types must operate. The major product types described in the AIS system standards are: Class A Vessel-mounted AIS transceiver