Communications systems - VMS
The communications system carries position reports and other messages from the Shipboard equipment - VMS , through space and surface lines, to the Fishery monitoring centre - VMS . The service providers used for the space segment in most fisheries VMS programmes are Argos, and Inmarsat-C and D+. Other service providers include Orbcomm and Qualcomm (EutelTRACS in Europe and Boatracs in North America). Very brief descriptions of these services are provided here. Readers are encouraged to visit the provider web sites.The Argos (CLS) system is carried on polar-orbiting satellites operated by the USA’s National Oceanic and Atmospheric Administration. The polar-orbiting satellites offer good coverage at high latitudes, and process one-way, ship to shore, communications (two-way communications are planned). Argos positions are provided in either of two ways: GPS positions for shipboard units that have an integrated GPS, and positions calculated by measuring Doppler shift for both units with GPS and those without it. Shipboard equipment for Argos service is manufactured by several companies. Inmarsat-C and Inmarsat-D+ services use geostationary satellites along the equator, providing almost global two-way coverage. Because of the satellites’ equatorial locations, coverage at very high latitudes is incomplete. Inmarsat offers several types of communication service, but Inmarsat-C and D+ are most suitable for VMS applications as they are cost-effective for text messages and data packets. Shipboard equipment for Inmarsat-C and D+ service is manufactured by several companies.
The Orbcomm system employs multiple satellites in low earth orbit. The Orbcomm earth stations process global, two-way data communications. Shipboard equipment for Orbcomm services is manufactured by several companies.
Two types of VMS programmes are available from Qualcomm – Boatracs and EutelTRACS. Position reports are provided in either of two ways: GPS positions for shipboard units that have an integrated GPS, and positions calculated by measuring Doppler shift (for units with and without GPS). EutelTRACS covers Europe and adjacent portions of the Atlantic Ocean, the Mediterranean and the Middle East. Boatracs covers eastern North America and adjacent portions of the Atlantic Ocean. The Qualcomm systems provide two-way communications, and shipboard equipment for Qualcomm service is manufactured by several companies.
Links to several providers of VMS communications systems (Note: FAO provides links to providers as an educational courtesy to readers, and does not endorse or promote any particular system):